From andre.kesteloot at ieee.org Fri Jan 4 11:49:17 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:35 2003 Subject: [Lf] m-FSK: SNR vs bandwidth] Message-ID: <3C35DD0D.A7E41899@ieee.org> James Moritz wrote: > Dear LF Group, > > I seem to be the only station so far that has had some success with both > WOLF BPSK and 7FSK modes over transatlantic paths, so here is my comparison: > > W!TAG was able to get perfect copy on my WOLF signal, so BPSK definitely > does work for DX communication; however, he remains the only transatlantic > station to do so, in spite of weeks of trying. In part this can be put down > to the varagies of propagation, but also many people struggled to get WOLF > to work well. The reason for this seems to be mainly the requirement for > accurate frequency and timing calibration (of the order of 1ppm), not a > trivial problem to overcome since the equipment most people are using was > not really designed with this in mind. Operation of the software and > hardware is not intuitive like QRSS/spectrogram programs.Transmitting using > this mode is relatively difficult too; although very simple QRP > transmitters are possible, envelope shaping is required for higher powers > to avoid causing unacceptable QRM, making high power transmitters > significantly more complex. In the context of the European 136k band, the > bandwidth of some 10s of Hz required by Wolf would be a problem if the mode > was being used by several stations simultaneously. None of these are > fundamental limitations - ingenious frequency calibration schemes have been > devised, some success has been had with modified "variable phase" keying to > control sidebands without amplitude modulation, it would be possible to use > narrower bandwidths for BPSK too. However, BPSK does require significant > time and effort on the technical side to get working. > > I would not claim any great technical superiority of 7FSK over other modes, > but from a pragmatic viewpoint it has several good points. It can be > generated by a simple extension of existing DFCW techniques, and received > using the spectrogram software that people are familiar with. The frequency > accuracy required is much more relaxed (of the order of 10ppm on receive), > and timing accuracy isn't really an issue. The bandwidth, although greater > than that of QRSS, is small enough. In its short history, readable 7FSK has > already been received by a number of transatlantic stations, so it > definitely works too. The big advantage is of course in the increased speed > compared to QRSS. > > As for the SNR vs. bandwidth considerations, other subscribers to this > reflector have more expertise than me - but I would observe the following: > Both QRSS and 7FSK are made up of dots, so the probability of any one dot > being corrupted by noise is the same. However, 7FSK transmits on 1 of 7 > possible frequencies, while QRSS uses only one, so it is 7 times more > likely that a corrupted dot will appear in a 7FSK signal in a given period > of time. However, fewer dots are required by 7FSK to send the same number > of characters by a factor of about 5.5, so the relative probability of a > character being corrupted in 7FSK compared to QRSS would be 7/5.5, ie. 1.3 > times as likely; not very different - about 1dB. I realise this is only > approximately true, not considering redundancy and so on, and would apply > only when the ratio of corrupted dots to uncorrupted is small, but you > would need this anyway for a QSO, and the tests over Christmas and before > show that these conditions do exist fairly often. > > I think long-distance LF communications can be done with either of these > modes, and probably many others too. Theoretically, I think the more > sophisticated modes like BPSK will win out, but will always have limited > popularity due to the more elaborate technical requirements. A mode like > 7FSK may not ultimately be as good, but it is quick and easy to get going > and operate. It is interesting that in the US Lowfer community this winter > has seen an explosion in the number of QRSS beacons and reception reports, > while last winter WOLF BPSK was a la mode. The distances being covered > don't seem to be much different, but more people are getting results. Where > there is an unpredictable element involved, like propagation, the chances > of the success of any particular mode are going to be tied up with how > many people have the capability and the inclination to use it - a > technically mediocre mode in use by 100 stations will probably get more > positive results than an excellent one being used by only two stations. > This is no excuse for complacency of course, but factors like ease of > implementation, compatibility, inertia and "does it match the curtains?" > all comes in to how successful something is - just look at the history of > the personal computer! > > Cheers, Jim Moritz > 73 de M0BMU From andre.kesteloot at ieee.org Mon Jan 7 18:09:37 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:35 2003 Subject: [Lf] LF QSO records Message-ID: <3C3A2AB1.A99C05BC@ieee.org> Dave Pick G3YXM wrote: > I have "The Matrix" on my web-site, it doesn't cater for 1-ways and I've not > added many cross-bands but it's supposed to be a record of the first QSO > between each pair of countries. If anyone knows of any that aren't recorded, > please let me know. > > It's at http://www.wireless.org.uk/matrix.htm [..] > 73. > Dave > G3YXM. From akestel at attglobal.net Wed Jan 9 10:39:02 2002 From: akestel at attglobal.net (Andre Kesteloot) Date: Thu Jul 3 13:44:35 2003 Subject: [Lf] Phase meter? Message-ID: <3C3C6415.9DC5D101@attglobal.net> Talbot Andrew wrote: > >- > >From: boffin1 [mailto:boffin1@compuserve.com] > >Subject: LF: Phase meter? > >I have belatedly seen your queery about phase. In the abstract their is > >no answer to your question for phase reqires a reference i.e the phase of > >something relative to ....??? (i.e another part of the wave). In the > >limit the phase must always close; Nature abhors odd bits of phase > >73, Roger, G2AJV. > ------------------------------------ > The original question, I believe, was for software that would show the phase > of received signal / audio tone based on an internally generated reference. > This would obviously have to be at a specified frequency, but could easily > be generated by software using a Numerically Controlled Oscillator (a DDS in > software). The procedure is to generate COS and SIN waveforms at the > specified frequency, which are jusst two sinewaves in software 90 degrees > apart. Multiplying each of these by the incoming signal gives two > products, I and Q components respectively, these are usually then passed > through a (software) low pass filter. When displayed on a graph such that > the I compont is on the horizontal axis and the Q component on the vertical > a good representation of the signal in vector space is seen. Such a display > is usually called a Vectorscope. > > A clean tone with no noise appears as a dot on the screen, whose distance > from the origin is the amplitude. A frequency error between the tone and > internal reference causes the dot to rotate around a circle at the > difference frequency - anticlockwise for a frequency too low and clockwise > for too high. So this is a very good way of measuring exact frequency. > Noise appears as a amorphous circle around the dot. The instantaneous > phase (relative to the internal reference, Roger) of a signal can be > determined immediately just by its position on the vectorscope > > Soundcards are usually too unstable for this - their internal clock sources > are notoriously drifty and innacurate. However, for those who understand > Windoze programming (All Hail !) it is quite a simple piece of software to > write. It needs a user defined NCO which can be tuned in very fine steps - > 0.01 Hz error only takes 100 seconds to complete a whole revolution. > Amplitude needs to be controlled - you can have a log/dB display of > amplitude versus radius. An alternative would be to use the left channel as > the signal input and the right as a user supplied reference tone. This > would not have the versatility of an NCO appraoch, but could ensure absolute > freqeuncy stability of the display. > > A more advanced and better solution would be to use a reference input tone > to continuously determine the Soundcard sampling rate, then use this > calculated figure in setting the NCO. > > I use the 56002EVM module with its clock locked to a freqeuncy standard to > do the downconversion of a signal sampled at 8kHz. The NCO is set in steps > of 8000 / 2^24 Hz. The zero frequency I/Q samples are filtered and > decimated (reduced in sampling rate) to values of 800 right down to 1.95 > samples per second. These are output to a PC via a serial link for further > processing. This basic tuning / decimation / filtering routine for the EVM > forms the workhorse of just about everything I do in the DSP line these > days, splitting the processing between two boxes really makes for easy > writing of software using a 66 MHz 486 running in a DOS environment ! > > -- > The Information contained in this E-Mail and any subsequent correspondence > is private and is intended solely for the intended recipient(s). > For those other than the recipient any disclosure, copying, distribution, > or any action taken or omitted to be taken in reliance on such information is > prohibited and may be unlawful. From akestel at attglobal.net Wed Jan 9 10:39:29 2002 From: akestel at attglobal.net (Andre Kesteloot) Date: Thu Jul 3 13:44:36 2003 Subject: [Lf] Phase meter w/ 56002 EVM Message-ID: <3C3C6431.84E68224@attglobal.net> Talbot Andrew wrote: > >- > >From: boffin1 [mailto:boffin1@compuserve.com] > >Subject: LF: Phase meter? > >I have belatedly seen your queery about phase. In the abstract their is > >no answer to your question for phase reqires a reference i.e the phase of > >something relative to ....??? (i.e another part of the wave). In the > >limit the phase must always close; Nature abhors odd bits of phase > >73, Roger, G2AJV. > ------------------------------------ > The original question, I believe, was for software that would show the phase > of received signal / audio tone based on an internally generated reference. > This would obviously have to be at a specified frequency, but could easily > be generated by software using a Numerically Controlled Oscillator (a DDS in > software). The procedure is to generate COS and SIN waveforms at the > specified frequency, which are jusst two sinewaves in software 90 degrees > apart. Multiplying each of these by the incoming signal gives two > products, I and Q components respectively, these are usually then passed > through a (software) low pass filter. When displayed on a graph such that > the I compont is on the horizontal axis and the Q component on the vertical > a good representation of the signal in vector space is seen. Such a display > is usually called a Vectorscope. > > A clean tone with no noise appears as a dot on the screen, whose distance > from the origin is the amplitude. A frequency error between the tone and > internal reference causes the dot to rotate around a circle at the > difference frequency - anticlockwise for a frequency too low and clockwise > for too high. So this is a very good way of measuring exact frequency. > Noise appears as a amorphous circle around the dot. The instantaneous > phase (relative to the internal reference, Roger) of a signal can be > determined immediately just by its position on the vectorscope > > Soundcards are usually too unstable for this - their internal clock sources > are notoriously drifty and innacurate. However, for those who understand > Windoze programming (All Hail !) it is quite a simple piece of software to > write. It needs a user defined NCO which can be tuned in very fine steps - > 0.01 Hz error only takes 100 seconds to complete a whole revolution. > Amplitude needs to be controlled - you can have a log/dB display of > amplitude versus radius. An alternative would be to use the left channel as > the signal input and the right as a user supplied reference tone. This > would not have the versatility of an NCO appraoch, but could ensure absolute > freqeuncy stability of the display. > > A more advanced and better solution would be to use a reference input tone > to continuously determine the Soundcard sampling rate, then use this > calculated figure in setting the NCO. > > I use the 56002EVM module with its clock locked to a freqeuncy standard to > do the downconversion of a signal sampled at 8kHz. The NCO is set in steps > of 8000 / 2^24 Hz. The zero frequency I/Q samples are filtered and > decimated (reduced in sampling rate) to values of 800 right down to 1.95 > samples per second. These are output to a PC via a serial link for further > processing. This basic tuning / decimation / filtering routine for the EVM > forms the workhorse of just about everything I do in the DSP line these > days, splitting the processing between two boxes really makes for easy > writing of software using a 66 MHz 486 running in a DOS environment ! From andre.kesteloot at ieee.org Wed Jan 9 21:55:55 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:36 2003 Subject: [Lf] Inductive RFID transmit spectrum] Message-ID: <3C3D02BB.EBDDE628@ieee.org> John W Gould wrote: > Inductive RFIDs that operate at 134.8kHz pose a possible treat in the future > to the noise floor in the 136kHz amateur band. A paper is currently being > considered internationally that would allow an increase in the modulation > sidebands, falling in the 136kHz band and elsewhere, from the RFID system. > > One item of detail omitted from the papers that are being reviewed is a > precise specification of the transmit spectrum from the RFID "readers" as > the interrogators are termed. It is assumed that it is a flat spectrum > with constant spectral density. > > Grateful if anyone can provide me with more detail of the system's > modulation scheme / transmit spectrum. > > 73 John, G3WKL > RSGB HF Committee > g3wkl@btinternet.com From andre.kesteloot at ieee.org Thu Jan 10 15:57:18 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:36 2003 Subject: [Lf] Overtaking Shannon's theory? Message-ID: <3C3E002E.F84136FA@ieee.org> ZEOSYNC'S MATHEMATICAL BREAKTHROUGH OVERCOMES LIMITATIONS OF DATA COMPRESSION THEORY International Team of Scientists Have Discovered How to Reduce the Expression of Practically Random Information Sequences WEST PALM BEACH, Fla. - January 7, 2002 - ZeoSync Corp., a Florida-based scientific research company, today announced that it has succeeded in reducing the expression of practically random information sequences. Although currently demonstrating its technology on very small bit strings, ZeoSync expects to overcome the existing temporal restraints of its technology and optimize its algorithms to lead to significant changes in how data is stored and transmitted. Existing compression technologies are currently dependent upon the mapping and encoding of redundantly occurring mathematical structures, which are limited in application to single or several pass reduction. ZeoSync's approach to the encoding of practically random sequences is expected to evolve into the reduction of already reduced information across many reduction iterations, producing a previously unattainable reduction capability. ZeoSync intentionally randomizes naturally occurring patterns to form entropy-like random sequences through its patent pending technology known as Zero Space TunerT. Once randomized, ZeoSync's BinaryAcceleratorT encodes these singular-bit-variance strings within complex combinatorial series to result in massively reduced BitPerfectT equivalents. The combined TunerAcceleratorT is expected to be commercially available during 2003. According to Peter St. George, founder and CEO of ZeoSync and lead developer of the technology: "What we've developed is a new plateau in communications theory. Through the manipulation of binary information and translation to complex multidimensional mathematical entities, we are expecting to produce the enormous capacity of analogue signaling, with the benefit of the noise free integrity of digital communications. We perceive this advancement as a significant breakthrough to the historical limitations of digital communications as it was originally detailed by Dr. Claude Shannon in his treatise on Information Theory." [C.E. Shannon. A Mathematical Theory of Communication. Bell System Technical Journal, 27:379-423, 623-656, 1948] "There are potentially fantastic ramifications of this new approach in both communications and storage," St. George continued. "By significantly reducing the size of data strings, we can envision products that will reduce the cost of communications and, more importantly, improve the quality of life for people around the world regardless of where they live." Current technologies that enable the compression of data for transmission and storage are generally limited to compression ratios of ten-to-one. ZeoSync's Zero Space TunerT and BinaryAcceleratorT solutions, once fully developed, will offer compression ratios that are anticipated to approach the hundreds-to-one range. Many types of digital communications channels and computing systems could benefit from this discovery. The technology could enable the telecommunications industry to massively reduce huge amounts of information for delivery over limited bandwidth channels while preserving perfect quality of information. ZeoSync has developed the TunerAcceleratorT in conjunction with some traditional state-of-the-art compression methodologies. This work includes the advancement of Fractals, Wavelets, DCT, FFT, Subband Coding, and Acoustic Compression that utilizes synthetic instruments. These are methods that are derived from classical physics and statistical mechanics and quantum theory, and at the highest level, this mathematical breakthrough has enabled two classical scientific methods to be improved, Huffman Compression and Arithmetic Compression, both industry standards for the past fifty years. All of these traditional methods are being enhanced by ZeoSync through collaboration with top experts from Harvard University, MIT, University of California at Berkley, Stanford University, University of Florida, University of Michigan, Florida Atlantic University, Warsaw Polytechnic, Moscow State University and Nankin and Peking Universities in China, Johannes Kepler University in Lintz Austria, and the University of Arkansas, among others. Dr. Piotr Blass, chief technology advisor at ZeoSync, said "Our recent accomplishment is so significant that highly randomized information sequences, which were once considered non-reducible by the scientific community, are now massively reducible using advanced single-bit- variance encoding and supporting technologies." "The technologies that are being developed at ZeoSync are anticipated to ultimately provide a means to perform multi-pass data encoding and compression on practically random data sets with applicability to nearly every industry," said Jim Slemp, president of Radical Systems, Inc. "The evaluation of the complex algorithms is currently being performed with small practically random data sets due to the analysis times on standard computers. Based on our internally validated test results of these components, we have demonstrated a single-point-variance when encoding random data into a smaller data set. The ability to encode single-point-variance data is expected to yield multi-pass capable systems after temporal issues are addressed." "We would like to invite additional members of the scientific community to join us in our efforts to revolutionize digital technology," said St. George. "There is a lot of exciting work to be done." About ZeoSync Headquartered in West Palm Beach, Florida, ZeoSync is a scientific research company dedicated to advancements in communications theory and application. Additional information can be found on the company's Web site at www.ZeoSync.com or can be obtained from the company at +1 (561) 640-8464. From dibene at usa.net Thu Jan 10 23:31:38 2002 From: dibene at usa.net (Alberto di Bene) Date: Thu Jul 3 13:44:36 2003 Subject: [Lf] Re: Overtaking Shannon's theory? References: <3C3E002E.F84136FA@ieee.org> Message-ID: <3C3E164A.E1819E77@usa.net> Andre Kesteloot wrote: > ZEOSYNC'S MATHEMATICAL BREAKTHROUGH OVERCOMES LIMITATIONS OF DATA > COMPRESSION THEORY > > International Team of Scientists Have Discovered > How to Reduce the Expression of Practically Random Information Sequences > [...] Funny, I thought that there were still two and half month before April 1st...:-) 73 Alberto I2PHD From lemaster at pressroom.com Fri Jan 11 19:02:28 2002 From: lemaster at pressroom.com (George Lemaster) Date: Thu Jul 3 13:44:37 2003 Subject: [Lf] Re: Inductive RFID transmit spectrum References: <3C3D02BB.EBDDE628@ieee.org> Message-ID: <001601c19afc$6db99700$40ca19d8@v2q9a1> Some clues may be found in the documentation for Texas Instruments Series 2000 LF RFID at: http://www.ti.com/tiris/docs/manuals/s2000.htm Some transmission format detail begins on page 24 of "Description of ....Transponders" : http://www.ti.com/tiris/docs/manuals/refManuals/mpt-tsp.pdf Also 'Reader System' appendix C, beginning on page 66 (field strength limits): http://www.ti.com/tiris/docs/manuals/rfm01-98.pdf 73 George WB5OYP ----- Original Message ----- From: Andre Kesteloot To: lf-amrad ; AMRAD Tacos Sent: Wednesday, January 09, 2002 9:55 PM Subject: Inductive RFID transmit spectrum] > John W Gould wrote: > > > Inductive RFIDs that operate at 134.8kHz pose a possible treat in the future > > to the noise floor in the 136kHz amateur band. A paper is currently being > > considered internationally that would allow an increase in the modulation > > sidebands, falling in the 136kHz band and elsewhere, from the RFID system. > > > > One item of detail omitted from the papers that are being reviewed is a > > precise specification of the transmit spectrum from the RFID "readers" as > > the interrogators are termed. It is assumed that it is a flat spectrum > > with constant spectral density. > > > > Grateful if anyone can provide me with more detail of the system's > > modulation scheme / transmit spectrum. > > > > 73 John, G3WKL > > RSGB HF Committee > > g3wkl@btinternet.com > > > > > _______________________________________________ > Tacos mailing list > Tacos@amrad.org > http://www.amrad.org/mailman/listinfo/tacos > From fgentges at mindspring.com Sun Jan 13 16:19:14 2002 From: fgentges at mindspring.com (Frank Gentges =?iso-8859-1?Q?K=D8BRA?=) Date: Thu Jul 3 13:44:37 2003 Subject: [Lf] CFA Message-ID: <5.0.2.1.0.20020113161144.024ca900@pop.mindspring.com> LFers, I have read the paper by Trainotti. (Short Medium Frequency AM Antennas, Valentin Trainotti, IEEE Transactions on Broadcasting, Vol 47, No. 3, September 2001.) It is a really good paper. It provides a great quantitative overview of about all the short antennas and their performance and characteristics. Then he analyzes the Cross Field Antenna. He builds and tests one and shows that it falls short of more conventional short antennas. I think this will put the CFA to bed. A great tutorial on short antennas and the strong and weak points of each. Frank Frank Gentges K?BRA LF web site at From dibene at usa.net Sun Jan 13 22:36:19 2002 From: dibene at usa.net (Alberto di Bene) Date: Thu Jul 3 13:44:37 2003 Subject: [Lf] CFA References: <5.0.2.1.0.20020113161144.024ca900@pop.mindspring.com> Message-ID: <3C41FDD3.2CD643D6@usa.net> Frank Gentges K?BRA wrote: > LFers, > > I have read the paper by Trainotti. (Short Medium Frequency AM Antennas, > Valentin Trainotti, IEEE Transactions on Broadcasting, Vol 47, No. > 3, September 2001.) > [...] Is that paper available on line, by chance ? TNX. 73 Alberto I2PHD From andre.kesteloot at ieee.org Mon Jan 14 12:16:11 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:37 2003 Subject: [Lf] Introducing Jason - and asking for cooperation] Message-ID: <3C43125B.4E5C8BCC@ieee.org> Alberto di Bene wrote: > Hello group, > > I have devised a novel coding scheme, and have written a new > software to support it. > > I have named it Jason, from the name of the coxswain of the mythological > ship Argo, which was headed to Colchis by the Greek hero Jason. > > The coding scheme of Jason is based on the ideas about IFK that can be found > on the Web site of Steve Olney, VK2ZTO. > > I need your cooperation to test it. I have done some preliminary tests, which > have given very good results, but a true test on the LF hasn't been performed > yet. Instead of cluttering this reflector with the gory technical details of Jason, > I invite you to visit this page : http://www.weaksignals.com/jason > > You can use Jason with a mosfet Class-D Tx, no need for a linear amp. > You can drive the Tx either using a DDS board connected via the parallel port or > the serial port, or up converting an audio signal generated by Jason. > > I tested only the audio interfacing. I need someone who volunteers for testing > the interfacing via the DDS board (I haven't one), with true on-the-air tests. > > Thanks for any cooperation > > 73 Alberto I2PHD From andre.kesteloot at ieee.org Tue Jan 15 21:55:14 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:38 2003 Subject: [Lf] LF: G3YXM received in Italy with Jason] Message-ID: <3C44EB91.382AB5CB@ieee.org> Alberto di Bene wrote: > > Hi Dave and the group, > > very good reception of your transmission in Italy : > > [Image] > > Your signal was rather weak here, and I had some QRN, which increased > suddenly > at 20:20 UTC > After some minutes the screen was this : > > [Image] > > Thanks for your time and patience Dave ! > > 73 Alberto I2PHD -------------- next part -------------- Skipped content of type multipart/related From andre.kesteloot at ieee.org Tue Jan 15 21:55:31 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:39 2003 Subject: [Lf] LF: G3YXM went on !] Message-ID: <3C44EBA3.AE63A2C4@ieee.org> Alberto di Bene wrote: > Well, when I thought the transmission was over, and > I was about to switch off the Rx, I checked again, > and, sure, Dave was still transmitting ! > > Strong QSB which at times wiped off your signal, > but I was able to copy this : > > [Image] > > When in the message there were errors, in the waterfall > your signal was totally absent. > > Well, I am satisfied of this first true test on the air ! > Now, before going to bed, I will prepare the version > with the option to slow it down. Tomorrow I will put it > on the Web site. > > Good night to all, and thanks especially to Dave for > his time and cooperation ! > > 73 Alberto I2PHD > -------------- next part -------------- Skipped content of type multipart/related From andre.kesteloot at ieee.org Wed Jan 16 14:36:11 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:39 2003 Subject: [Lf] Jason test sigs] Message-ID: <3C45D62B.318ED624@ieee.org> Alberto di Bene wrote: > James Moritz wrote: > > > If the centre frequency is > > F, and the spacing between tones is f, the possible tone frequencies are F > > +/- (n-0.5)*f where n is an integer from 1...16. Therefore there are 32 > > possible equally-spaced tone frequencies from F-15.5f to F+15.5f. Is this > > correct? > > > > Hi Jim and the group, > > yes, correct, that's how the information is encoded in Jason. > There is another possible format, which has pros and cons. > It has been also suggested by Stewart Nelson. I had initially, > when designing Jason, dismissed it, but now I am here asking > your collective opinion. > > Presently only the absolute value of the frequency delta is used > to encode the information. If I use also the sign, I have this results : > > -Pros The band occupied is nearly halved, from 32 slots, it goes > down to 17 slots. > > -Cons The system is no more sideband independent. Now it is > immaterial whether the RX is set to LSB or USB. > This would not be any more the case with the alternate scheme. > > So, what would all you judge more important, sideband independence, > or bandwidth used ? Your vote will decide the final format for Jason. > > 73 Alberto I2PHD From andre.kesteloot at ieee.org Wed Jan 16 14:38:00 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:39 2003 Subject: [Lf] Jason V0.91 released Message-ID: <3C45D698.85B143F@ieee.org> Alberto di Bene wrote: > Hello Group > > I have just uploaded the version 0.91 of Jason. > The mods are : > > - The Options menu now allows to set the speed > to Normal or Slow (for PCs in the 200 MHz class) > > - The center frequencies both for reception and transmission > (when using the audio output) are now user-selectable. > > The problem of excessive blooming of the waterfall trace > is being investigated. Anyway it shouldn't affect the decoding, > as the AGC applied to the visual trace is not used elsewhere. > > Also the problems of occasional double letters, and systematic > errors are under scrutiny. > > Please test it in the Slow setting with a slow PC. > Before someone asks, the settings are not remembered. > It is one of the touches that will be added to the final version. > > 73 Alberto I2PHD From andre.kesteloot at ieee.org Thu Jan 17 22:15:39 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:39 2003 Subject: [Lf] G0MRF/SM6LKM DDS VFO and Jason] Message-ID: <3C47935B.BECB12D5@ieee.org> Johan Bodin wrote: > Hello > > I know there are some DDS users/programmers out there! > > We have probably not seen the final variant of "sequential single tone > modulation" yet. So, in order to avoid unnecessary (and painful) PIC > software changes in the future, I'd suggest that we establish a standard. > > It would be very nice if we could agree on a simple serial protocol > that would allow any PC program, be it DOS or Windoze, to take total > control over the DDS (I know that Andy G4JNT has done something > in this direction). > > I am in the process of rewriting the PIC software for G0MRF's DDS > board, a serial input port is on the "todo" list. > > If the DDS clock frequency, and possibly also a division ratio and offset > frequency, is known to the PC software (via a setup menu or whatever), > the math can be done in the PC, only the DDS phase increment has to be > sent to the DDS box. > > Proposed serial protocol: > > 9600 baud, 8N1. > > Only printable ASCII characters are used. > > '=' is used as "start-of-message" character. > > The '=' is followed by eight hexadecimal digits representing the 32-bit > phase increment, MSB first! Example: "=0245FD4C3" > > The DDS box changes the output frequency if it receives 8 consecutive > valid hex digits after the leading '='. In case of error, it will do nothing > but continue putting out the old frequency and wait for a new > '=' start character. > > A simple checksum byte (two hex characters) could be added at the > end to prevent the TX from exploding if the frequency data should get > corrupted from RF interference... Either "vertical parity" (just XOR the > bytes) or a modulo 256 sum. CRC seems to be overkill... > > (Alberto has indicated that he might add direct DDS TX control to Jason > if all DDS owners/programmers can agree on a serial protocol) > > Please comment! > > 73 > Johan SM6LKM From andre.kesteloot at ieee.org Fri Jan 18 08:29:51 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:39 2003 Subject: [Lf] G0MRF/SM6LKM DDS VFO and Jason] Message-ID: <3C48234F.C4E8CB8D@ieee.org> Johan Bodin wrote: > Larry VA3LK wrote: > > > Please, for serial protocol just use what Andy has already done or do the > > exact same functions, Integer steps at the limits of the DDS chip. > > OK. It looks like we already have a standard. Andy, can you describe your protocol? > > > The worst result for me would be doing something like 10 milliHz steps, > > which again would be not quite 10 milliHz for those with different > > Reference oscillator frequencies. The use of a second DDS to make a nice > > round integer clock for a DDS would be the best solution but is overly > > costly at the moment. > > If we all clock our DDS chips with 5 or 10MHz from frequency standards, we > will have common "channels" although the numbers will not be nice (a lot of > ugly decimals). The 10MHz guys (including me) will only have access to > half the number of "channels" because of the doubled step size... However, > 901943 "channels" on the 136kHz band is enough for me :-) > > > PS, one final point, I would implement a trigger input on the PIC as well > > so that one can easily make the whole DDS setup coherent to a 1 Second > > resource as well. I have that here now on the BPSK and it could be used to > > squeeze a bit out of the system..... > > Yes, I am thinking about a way to implement this in the new software for the > G0MRF DDS board. It is probably a good idea to make soft phase > transitions considering the huge reactive power that is circulating in the > antenna circuits at the QRO stations. Swiching phase 180 degrees > instantaneously in such a setup would be like throwing in the reverse gear > when driving forward at 100 MPH... > > 73 > Johan SM6LKM From andre.kesteloot at ieee.org Fri Jan 18 08:30:36 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:40 2003 Subject: [Lf] [Fwd: LF: G0MRF/SM6LKM DDS VFO and Jason] Message-ID: <3C48237C.4797768C@ieee.org> Talbot Andrew wrote: > >OK. It looks like we already have a standard. Andy, can you describe your > protocol? > I'll send it out under separate cover. > > >If we all clock our DDS chips with 5 or 10MHz from frequency standards, we > >will have common "channels" although the numbers will not be nice (a lot of > > This is too prescriptive. For instance, I am looking at a simple GPS > locking scheme that will allow any frequency that is a multiple of 1Hz to be > locked giving very good long term stability, but poor short term over a few > seconds - suitable for long duration signalling purposes. Using a > 4.194304MHz is perfect for DDS synths as 'nice' frequencies occur > automatically. The step is 1/1024Hz so 1Hz steps and its subdivisions are > exact > > >It is probably a good idea to make soft phase > >transitions considering the huge reactive power that is circulating in the > >antenna circuits at the QRO stations. Swiching phase 180 degrees > >instantaneously in such a setup would be like throwing in the reverse gear > >when driving forward at 100 MPH... > > A Tx with a guard circuit such as the Decca one can survive such abuse - the > only real problems is an ethical one of switching sidebands - but a spike of > a few 100s of microseconds, a function of the antenna bandwidth, every few > 10s of seconds isn't going to annoy too many people. > > BTW, What's MPH in Sweden - or any other country outside the US/UK for that > matter ;-) > > Andy G4JNT > > -- > The Information contained in this E-Mail and any subsequent correspondence > is private and is intended solely for the intended recipient(s). > For those other than the recipient any disclosure, copying, distribution, > or any action taken or omitted to be taken in reliance on such information is > prohibited and may be unlawful. From andre.kesteloot at ieee.org Fri Jan 18 08:29:15 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:40 2003 Subject: [Lf] [Fwd: LF: RE: G0MRF/SM6LKM DDS VFO and Jason] Message-ID: <3C48232B.4DBB9A0E@ieee.org> Talbot Andrew wrote: > >From John Bodin > >It would be very nice if we could agree on a simple serial protocol > >that would allow any PC program, be it DOS or Windoze, to take total > >control over the DDS (I know that Andy G4JNT has done something > >in this direction). > > My DDS control protocol allows the 32 bit frequency word or 5 bit phase to > be sent as printable Ascii hex characters using a simple serial protocol > with simple handshaking, useable from any terminal or driver software, at > 19200 baud. Driver software reads back user data from the DDS controller to > let this know the clock frequency. That way, the software can be > independant of any particular DDS unit it has to control. (Very useful when > you have five DDS modules in the shack operating from clocks ranging from 5 > MHz up to 94.45 MHz and soon 4.194304MHz as well) There is also a module > address facility built in (thanks to Larry for that idea) to allow multidrop > use where one serial line can control several DDS units, a-la Icom C-IV > interface. Last option is a command that updates the frequency or phase in > the DDS only after an external trigger pulse. This makes GPS timed PSK or > FSK straightforwrd, after the new value is sent to the DDS controller, the > new value will appear exactly 3.2us after the UTC timing pulse. > > Summary of the DDS module commands : > > ------------------------------------ > The first character sent is a Board Address which precedes all commands. > This is a single Hex character sent as ASCII 0 - F and potentially allows > up to 16 modules to be driven from the same COM port. If correctly > addressed, the module responds with a Z [cr][lf] and this response sould be > waited for > > The next character is a command which may have hex data following it. > > Q Followed by eight hex digits for the frequency command word > terminated by a carriage return > P Followed by two hex digits for phase word and [cr] > U Writes the data sent above to the AD9850 DDS chip > T Writes the data to the AD9850 after the next 0/1 transition on the > external trigger input > W As for U, but also stores the data in the PIC's non-volatile EEPROM > memory for switch on next time. > Y Followed by one Hex digit, changes the board address and stores in > EEPROM. No [cr] needed > K Followed by 10 hex digits & [cr]. Read back user data, usually clock > frequency > R Readback current data values in operation - not necessarily those in > EEPROM > > So, to update the frequency (to one mentioned a lot on this reflector :-| > the following characters are sent assuming the board address is 7 The dot > . means wait for a response : > > 7.Q06F58E8C[cr] > 7.U > > Andy G4JNT > > -- > The Information contained in this E-Mail and any subsequent correspondence > is private and is intended solely for the intended recipient(s). > For those other than the recipient any disclosure, copying, distribution, > or any action taken or omitted to be taken in reliance on such information is > prohibited and may be unlawful. From fgentges at mindspring.com Sun Jan 20 17:09:14 2002 From: fgentges at mindspring.com (Frank Gentges K0BRA) Date: Thu Jul 3 13:44:40 2003 Subject: [Lf] Re: [Lowfer] Re: New Antenna Message-ID: <003f01c1a1ff$19996420$e30ab73f@mercury> Alberto, I talked to Crystalonics last week. The QST article exhausted their supply of these transistors. They made a new run of these transistors and they are again available. They said they still get about 5 or 6 orders a week for these transistors for the QST project. Do not forget to tell them that as they have a special deal for that project, otherwise they may not want to deal with you for one or two transistors. I do not know of any suitable direct replacements. These are special high grade transistors and have not been sold in reels of 5000 although I suspect they would like to. :-) If you do not want the highest performance, I make some suggestions on our web site on using U310s or J310s in the same design with 12 volts and different bias and you can eliminate the heat sink. You might be disappointed with the intermod performance as the intercept point is around 20 dB lower. However, with 12 volts, it makes a good antenna for your LF mobile rig. Our web site is at . Frank -----Original Message----- From: BOB RIESE To: lowfer@mailman.qth.net Date: Sunday, January 20, 2002 1:07 PM Subject: Re: [Lowfer] Re: New Antenna >That is a good question > >I ordered 2 of them before Christmas and >received them within a few days. I suspect >other devices of the same class will work >here is Franks addr. ,he may be of some help >I was planning to order a back up unit so I hope >the production run has not been shut down > > > fgentges@mindspring.com > >Bob > > > > >On Sat, 19 Jan 2002 18:13:16 +0100 Alberto di Bene >writes: >>Bob Riese srote: >> >>> this is a real easy project to build. the PC boards are from FAR >>and >>> total price to me >>> came to 40 bux. Without a Junk Box probably could be done for 60 to >>70 >>> bux >> >>Where did you find the CP-666 ? I contacted Crystalonics, >>but they have sold out all those they had... TNX >> >>73 Alberto I2PHD >> >> >>_______________________________________________ >>Lowfer mailing list >>Lowfer@mailman.qth.net >>http://mailman.qth.net/mailman/listinfo/lowfer >_______________________________________________ >Lowfer mailing list >Lowfer@mailman.qth.net >http://mailman.qth.net/mailman/listinfo/lowfer From andre.kesteloot at ieee.org Tue Jan 22 17:34:45 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:41 2003 Subject: [Lf] Questions about Jason.] Message-ID: <3C4DE905.E0672193@ieee.org> Rik Strobbe wrote: > >Rik ON7YD is much expert than me in QRSS speed calculations, but let's try : > >suppose I want to send CQ DE I2PHD > >Unless my computation is wrong, that amounts to a total of 106 dot lengths, > >so the time needed is the following : > >QRSS3 106 x 3 = 318 seconds, i.e. 5 minutes, 18 seconds > >QRSS10 106 x 10 = 1060 seconds, i.e. 17 minutes, 40 seconds > >QRSS60 106 x 60 = 6360 seconds, i.e. 1 hour, 46 minutes > >Jason 12 characters / 2.5 = 4 minutes, 48 seconds > > > >I leave to Rik the computation for DFCW... > > In DFCW it would be a length of 40 dots so : > DFCW3 = 2 min 0 sec > DFCW10 = 6 min 40 sec > DFCW60 = 40 min > > If we simplify a bit and assume that SNR is only determined by the > dotlength we would have to compare Jason with QRSS12 or DFCW12 : > QRSS12 = 21 min 12 sec > DFCW12 = 8 min 0 sec > Jason = 4 min 24 sec (I count only 11 characters) > > The other way arround, if we want to transmit the text at the same speed as > Jason we would need to use QRSS at 2.5 sec/dot or DFCW at 6.6 sec/dot. > This would make QRSS about 6.8dB and DFCW about 2.6dB inferior to Jason. > In the real world the differences will be a bit less since Jason is using a > larger bandwidth. > > 73, Rik ON7YD From andre.kesteloot at ieee.org Thu Jan 24 09:45:50 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:41 2003 Subject: [Lf] [Fwd: LF: Soldering down fine-pitch parts] Message-ID: <3C501E1E.AED9004@ieee.org> Steve Dove wrote: > Greetings, > > I find the best tool for sticking down fine-pitch parts is an intern. > But that's cheating, really. There is one truly gruesome, > cringe-worthy technique that I've used when pushed, and always > successfully, to stick dsps and fpgas down. It takes a bit of nerve. > > With best eyeballs, aided or otherwise, line up the chip onto the > pads; restrain it (g-cramp etc.) such that it won't budge. With a > normal-sized iron (no need for a really teensy tip at this point) > solder all the pins along each side in turn down onto all the pads; > the result will be a solid bar of solder along each side of the chip, > engulfing the pins. Naturally, don't go overboard, but all the > adjacent pins will be stuck to each other as well as the pins being > stuck to their appropriate pads. Try not to panic or cry. > > The next phase is to use solder-wick (the real stuff, not coax > braid) to drain off the excess solder; gently slide the wick in line > with the pins, not sideways 'against the grain', methodically around > the chip. Use a magnifying glass to peer between the pins for > sneaky bridges; wick more if you have to. > > Any human attempt at laying these things down will always result > in a long period of squinting, cleaning and picking between its teeth > with a scalpel, including this, but it is amazing how well this horrible > method works. Never lost a device. Oh, except for the dsp on which > a mold ejection dimple was more prominent than the 'pin 1' marker, > resulting in an 80-pin part glued on 180 degrees out . . . > > Cheers, > > Steve From andre.kesteloot at ieee.org Fri Jan 25 09:31:05 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:41 2003 Subject: [Lf] Jason DDS software released Message-ID: <3C516C29.87B34DA1@ieee.org> Johan Bodin wrote: > Hi > > Version 1.0 of the new Jason software for G0MRF's DDS is now > available. > > I found some time to test and debug the program on real hardware. > It appears to work very well now. > > The frequency range has been extended to cover 10Hz - 200kHz. > I am not sure if the hardware (filters etc.) will handle this range though... > > I will be happy to e-mail the program to anyone interested. > > 73 > Johan SM6LKM From andre.kesteloot at ieee.org Fri Jan 25 09:32:17 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:41 2003 Subject: [Lf] LF antenna gain] Message-ID: <3C516C71.10A793AD@ieee.org> Rik Strobbe wrote: > Hello Walter, > > You are raising a question I have been thinking about for quite some time. > Even after discussion with some antenna specialists I didn't come to a > conclusion. > You are right stating that the gain figures you mention for a short > vertical (4.77dBi or 2.62dBd) is based on the directivity (as for any gain > from any antenna). And this directivity is caused by interference of the > signal radiated 'into the air' and reflected by the (perfect) ground. > In fact a vertical monopole can not radiate without some form of > 'counterweight', wether it is the ground, some form of radial system or > even just the shielding of the coaxcable it is fed through. > > Some time ago I did a simple test : I built a small battery operated xtal > oscillator, using a CMOS gate (7400) and a 3.579MHz xtal running on a 9V > battery. I did put the whole thing a a small plastic (not metal !) box, > connected a 1m piece of wire (= antenna) to the oscillator output and hung > it on the brach of a tree (few m high) at about 100m from the shack. Using > my TS440 and a 1m wire antenna I could barely hear the signal. Next I cut > 50cm of wire from the oscillator's antenna and connected it to the minus of > the battery and hanging down, as counterweight (in fact making a kind short > vertical dipole). > Now the signal was very clear, I assume at least 10-20dB stronger. Changing > the position of the counterweight wire from vertical to horizontal made the > signal sleightly weaker (few dB) and adding a number of additional > horizontal counterweight wires increased the signal again. > > I believe this confirms the fact that a vertical monopole is not much of a > radiator without a counterweight. > > Now returning to your question : what is the gain (directivity) of a 'real > world' short vertical monopole ? > As you mention only a very small part of the transmitter power is radiated > (typical between 1% and 0.01% of the power for amateur sized antennas). > But this means that the part that is radiated 'sees' some kind of > counterweight. Unfortunately is it impossible to know the shape and > dimension of this counterweight and I believe that the directivity of the > antenna just depends on this. > For example : assume you have a full size (half wave) vertical dipole. This > antenna will have a gain of 0dBd (obvious) or 2.15dBi. Further assume that > the lower half of the dipole is a multi-strand wire and you 'untwist' all > the strands. Now you get a lot of parallel wires, but nothing will change > on the antenna behaviour. Next you start to tilt all the parallel wires, > creating a kind of Ground Plane antenna. Assuming the number of wires would > be endless the antenna directivity would slowly increase from 0dBd/ 2.15dBi > (all wires vertical) to 3dBd /5.15dBi (all wires horizontal). This last is > the gain of a quarter wave monopole. > So in practice the directivity of a short vertical monopole over an > imperfect ground will be somewhere between the gain of a short vertical > dipole (1.77dBi / -0.39dBd) and the gain of a short vertical monopole over > perfect ground (4.77dBd / 2.62dBd). > > That's the way I see it, no claims to be 100% correct. But I hope it helps. > > 73, Rik ON7YD > > At 10:04 25/01/02 +0000, you wrote: > >Could one of you experts help me with the following please: > > > >A short vertical monopole antenna over perfect ground has a gain relative > >to isotropic of 4.8 dB. > >A half-wave dipole in free space has a gain rel. isotropic of 2.15 dB > >Therefore, a monopole should have a gain of 2.65 dB over a dipole. > >So the theory goes............ > > > >But look at the qualifier on the short vertical gain - it has to be > >operating over "perfect ground". No amateur has "perfect ground"; at least > >not that I am aware of. I haven't heard of anyone laying out 36 radials 550 > >metres long under his antenna (not even G3KEV.......yet!) > > > >So nearly all the energy that goes into the ground is dissipated and does > >not return to the feedpoint. Therefore it cannot reinforce the radiation > >pattern. In that case, does the theoretical gain still hold? > > > >Gain is only obtained from directivity. Directivity can be calculated from > >physical considerations but the equation to obtain gain from directivity > >is G = e*D , where G = power gain, D = directivity, and e = radiated > >power/total power. The "gains" quoted above are actually theoretical > >directivity figures but they assume that e = 1, that is, that there are no > >ground losses (as the definition states) and that accordingly gain is the > >same as directivity. > > > >Not so in an average amateur situation, where e = 1/1000 (1w radiated for > >1000w input) so G = 0.001*4.8 = .0048 dB. In other words, the average > >amateur LF antenna is no better than isotropic. > > > >Or should I be ignoring earth losses and only counting copper losses? > > > >Walter G3JKV. > > > > > > > > > > > > > > > > From andre.kesteloot at ieee.org Fri Jan 25 12:31:05 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:42 2003 Subject: [Lf] Re: LF antenna gain] Message-ID: <3C519659.ADE76A0A@ieee.org> James Moritz wrote: > At 10:04 25/01/2002 +0000, you wrote: > >...So nearly all the energy that goes into the ground is dissipated and > >does not return to the feedpoint. Therefore it cannot reinforce the > >radiation pattern. In that case, does the theoretical gain still hold? > > > >Gain is only obtained from directivity. Directivity can be calculated > >from physical considerations but the equation to obtain gain from > >directivity is G = e*D , where G = power gain, D = directivity, and e = > >radiated power/total power... > Dear Walter, LF Group, > > Not sure if I'm an expert, but... > > I think the losses that the signal is subject to between transmitter output > and receiver antenna can basically be divided into 2 types: > > Firstly, the losses that are incurred in producing a current in the antenna > in the first place. In the case of a vertical it is necessary to generate a > huge voltage gradient between the antenna element and earth in order to get > useful current to flow, and this field gives rises to large losses in > materials in that field; the earth itself, buildings, trees; the antenna > wire and it's immediate environment can be modelled as a lossy capacitor. > The theorists say that it is the RF current in the wire that is actually > causing the propagating E and H fields, so the losses due to the electric > field are not really "radiation" losses and make up the "e" part of the > gain formula. These are the losses which make the feed point resistance of > the antenna greater than the radiation resistance - the power dissipated by > the radiation resistance is that part which is being radiated away, and > wether it is absorbed or carries on propagating, it does not come back and > affect the impedance of the antenna > > Given that a particular current is produced in a wire of a particular > geometry, the radiation pattern (and so the "D" part of the formula) can be > calculated either analytically or a numerical result obtained using NEC or > something similar. "Image" currents in a ground plane are taken into > account. The radiation pattern for a monopole over lossy ground uses a > model for the ground which, as I understand it, is a plane surface with a > reflection coefficient of magnitude < 1 to account for the energy "radiated > into the ground". This type of modelling is one way of producing ground > loss curves. As PA0SE pointed out some time ago, The lossy ground model > produces different radiation patterns at different distances from the > antenna. The default radiation pattern displayed by EZNEC and shown in the > text books is the "far field" pattern, mathematically the radiation pattern > at a distance tending to infinity. For lossy grounds this inevitably has a > null at ground level, because over very large distance, the ground wave > will be attenuated very much more than the signal propagating through > space, while a monopole over perfect ground has maximum signal at zero > elevation. However, as the distance decreases, the attenuation of the > ground wave is reduced, until at short distances, where the excess loss due > to ground losses is negligible, it turns out that the monopole over lossy > ground has much the same radiation pattern and D as the perfect ground case. > > This actually seems to be close to the truth - calculating the field > strength produced by my piece of wet string with a certain current in it by > using a NEC model consisting of perfectly conducting wire over a perfect > ground gives results that are within a few dB (usually a few dB higher) of > reality, over distances between 1 - 10km. It seems reasonable that the few > dB's additional "site loss" that occurs could be explained by the obstacles > close to the antenna which the radiated signal runs into - since higher > antennas that reach above this local clutter have reduced site loss, at > least on the basis of the very limited data that is available. > > So in summary: There are "antenna" losses, the power dissipated by the > antenna and its near environment whilst a certain current is flowing, which > are responsible for the efficiency "e" part of the gain formula, and which > determine the loss resistance of the antenna.. The directivity D is > affected by the distance from the antenna - close in, D is much the same as > an ideal monopole, far away the ground losses modify the radiation pattern. > Due to the very low values of e for all amateur antennas, G will always be > a large negative number of dB, however. Calculating the radiation > resistance and measuring the antenna current is the best easily done way of > determining what ERP is being radiated, since it does not require knowledge > of the antenna losses, only D, which is much the same for any electrically > small vertical antenna, ie. 1.8 relative to a dipole in free space. So ERP > = D.Iant^2.Rrad. In practice, the actual ERP may be lower by a few dBs > "site loss" > > There are lots of loose ends to this - it means that the radiation pattern, > gain, and so by definition the value of ERP, depends on the distance > at which it is measured where ground losses are significant. Also, > modelling the ground as a 2 dimensional plane is not very satisfactory - > currents and fields exist within the ground, as the cave radio guys well > know! Significant LF radiation from "earth" antennas has been demonstrated. > NEC just does not seem to model real grounds well where one part of the > antenna actually has a ground connection. More work needs doing on the > "site loss". The lobed radiation pattern of verticals shown in the > textbooks is fine at HF, but at LF the "upwards" components of the radiated > signal will be bumping into the ionosphere and coming back down long before > the ground wave has decayed. One could spend a whole lifetime on this sort > of thing... > > Cheers, Jim Moritz > 73 de M0BMU From andre.kesteloot at ieee.org Fri Jan 25 23:14:46 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:42 2003 Subject: [Lf] Improvements to WWVB Message-ID: <3C522D36.C17022C9@ieee.org> Improvements to the old WWVB Tx http://www.boulder.nist.gov/timefreq/general/pdf/1406.pdf Andr? N4ICK From andre.kesteloot at ieee.org Sat Jan 26 11:33:43 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:42 2003 Subject: [Lf] USART in the 16F628 Message-ID: <3C52DA67.7D40A7F6@ieee.org> Larry Kayser wrote: > Greetings: > > I have for some days been struggling with achieving consistent and accurate > serial port operation, especially when the Interrupts are being hit at a > high rate. The APNOTE from MICROCHIP does not work most of the time and > never worked properly. However a fine piece of work by Tom McGahee, > PICUART.ASM for the 16C74A should be adaptable to the 16F628. > > It was adaptable and works like a charm. I have now tried this with the > following Oscillator configurations. For the 16F628, the Internal 4 MHz, > an external 4 MHz crystal, a 1.8432 MHz crystal and with a high speed > 16F628 it ran just fine with a 21.7 MHz crystal. > > I will send any and all who ask a copy of this ASM file, which I happen to > call PIC8_4B.ASM, configured to run on a 4 MHz crystal or 4 MHz internal > oscillator by just compiling it with MPASM. > > I will decline to express my thoughts about Microchip documentation and > product support. It is suffice to say that my first copy of CPM-80, the > one with both handwritten and typewritten documentation from Gary Kendall > about 1976/7 was of higher quality and vastly more accurate than what I > have received from Microchip for the 16F628. > > Larry Kayser > VA3LK From andre.kesteloot at ieee.org Sun Jan 27 12:02:55 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:42 2003 Subject: [Lf] DDS controlled via soundcard Message-ID: <3C5432BF.357BE494@ieee.org> DL4YHF@aol.com wrote: > Hi all, > > During a nice QSO in Jason mode today, and thinking about this and > that, a crazy idea went through my brain. Maybe it's only good for the > waste bin but how about this: > > Let the PC produce a digital control word for a DDS VIA THE SOUNDCARD > ? > > A DDS like the AD9832 needs a special serial control word, which is > generated by a PIC processor in most cases. Three digital lines are > required. How about "producing" the control word for the DDS via the > SOUNDCARD ? We could either use a stereo output for clock+data > (producing digital signals) , a few clamping diodes, two or three > transistors and possibly a monoflop for the FSYNC signal (a third > control line from PC to PIC). An alternative would be using different > levels for the FSYNC, but proper level adjustment and clamping would > be required because most audio outputs are only "AC coupled". > > Johan (SM6LKM) has written a routine in "C" for PIC controllers which > I have adapted to run under DOS, using the parallel port. But it's > complicated to do this under windoze, especially if the DDS shall be > controlled in a highly "synchronous" way through the parallel port. > > > What would be the benefit of using the soundcard to drive a DDS ? > - you wouldn't need a programmed PIC processor acting as an interface > between PC and DDS. > - you wouldn't need a LPT interface which is tricky to access under > Windoze NT + XP. > - you wouldn't need a serial interface which does not exist on some > cheap notebooks. > - no need to fool around with USB programming > - The serial control word for the DDS chip can be timed very precisely > under windoze. A > continuous output (with update the DDS every 100 ms or so) is > possible. > > > Disadvantages: > - It's not a 'stand-alone' solution. A PC (or at least one of these > tiny PDA's) is always needed. But which of the "modern modes" runs > without a PC ? > - To implement this, basic knowledge of Windoze API programming is > required. But I know at least one other reader of this reflector who > has.. ;-) > > > If this sounds interesting, let me know and I'll do some more > "research". The result could be a routine which produces raw 16-bit > analogue samples to drive an AD9832 (which is the only DDS I have at > the moment). > > 73, > Wolf DL4YHF. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://atanasoff.rf.org/pipermail/lf/attachments/20020127/8d8d1e5c/attachment.html From andre.kesteloot at ieee.org Mon Jan 28 08:44:23 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:43 2003 Subject: [Lf] Novegro Hamfest Message-ID: <3C5555B7.52F16A75@ieee.org> Alberto di Bene wrote: > Hello Group, > we had two nice days at the hamfest of Novegro, near Milano. > Firstly, the weather was good, sunny, not even too cold, about > 7 - 8 degrees Celsius. Lot of people at the fair, and to our boot. > We were side by side with those demonstrating the first commercial > version of the EH antenna, so many of the visitors, after having > heard how well it performed, and how it generates the Poynting > vector, blatantly defying a couple of Maxwell equations, then > came to us asking what those funny shapes on the screen stood > for. "Is it PSK31 ?" - "No sir, it is a way of communicating on the > LF using very slow CW, with dot length of 3 seconds and more, > up to 60" - "Oh, I see.... but why so ? Even Marconi, when he sent > his famous three dots, used a faster speed..." > At this point, we had two choices : convincing him that he was the > perfect buyer for the EH antenna, and that he could not do without one, > or starting a long and boring explanation about S/N ratios, frequency > analysis, time and resolution dualism, etc. > We used one or the other approach after having "smelled" a little who > we had in front of us. We hope to have in the two days gained a few > new adepts for the "under the noise" world. Time will tell.... > > The QRN was tremendous... Friday afternoon Claudio IK2PII had > installed a loop outside the fair building, in the open, and he told me > that evening that the noise level was quite acceptable. > Not so on Saturday and Sunday... with hundreds of PCs and monitors > switched on, we were unable to copy Giulio IK2DED, who transmitted > with 100W from his QTH less than 100km away. So it is remarkable > that we copied, Saturday with T report and Sunday with M- report, > Laurie G3AQC ! We copied also Valerio IK5ZPV, but his QRO > station usually produces an aurally copyable signal at my QTH. > > To put an end to this long message, we are satisfied of the affluence, > and we thank Laurie, Jim, Wolf, Valerio, Cesare, Giulio and in general > all those who put a signal on the air during the weekend. > > 73 Alberto I2PHD From andre.kesteloot at ieee.org Mon Jan 28 15:46:17 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:43 2003 Subject: [Lf] Frequency standards for LF. The next generation] Message-ID: <3C55B899.1D95D86@ieee.org> Talbot Andrew wrote: > Looking at frequency standards for LF, the requirements are slightly > different than for the higher frequencies. For microwaves, where > instantaneous frequency (over a few seconds) needs to be very good to avoid > chirp on SSB or CW, a high stability oscillator has to be used as part of > the Phase Locked Loop, locked to a master reference source. The master > source can be off air such as Droitwich or TV Sync pulses in which case loop > bandwidths can be made wide enough that lockup to a few parts in 10^-9 is > possible in minutes. Both these are very good in the short term, but may > have glitches or anomalies if relied on for hours at a time. Another > standard in use is that by Brooks Shera that locks a high quality VCXO to > 1PPS from a GPS receiver - requiring hours to lock up and a very good VCXO. > In all cases long term accuracy is that of the standard used - typically > parts in 10^-10 or better. Designs for all these have appeared in Amateur > publications over the last few years. > > For LF, however, particularly where we are integrating over many seconds > worth of data, the requirement for short term stability goes away, provided > this period is significantly shorter than the signalling interval; long term > stability is now even more important. So the requirement for the high > stability VCXO has gone, and all we need is a locking scheme that can > maintain phase to within a few degrees over a few seconds, and in the long > term remain perfectly locked to the master reference without cycle slippage. > > Here a GPS receiver really excells itself. Rather than try to phase lock an > oscilltor at a 1Hz reference frequency which would lead to inordinately long > lockup times, I have used a frequency locked loop, based very roughly on the > old Huff & Puff stabiliser published in the 1970s. A sort of H & P > stabiliser Mark 3. > > The idea is this : > > A VCXO runs at any frequency that is an exact multiple of 1Hz (I use > 4.194304MHz ). This directly clocks an 8 bit synchronous counter made up of > 74HC161 chips. The outputs of this are connected to an 8 bit latch, > 74HC374, and the 1 Pulse per Second signal from a GPS receiver module > latches the count once per second. The latch outputs then contain the > counter contents, updated very second. For frequencies that are an exact > multiple of 256Hz, the reading should therefore not change. For frequencies > that are not an exact multiple of 256, the count will increment each second > by (Frequency MOD 2565). If the frequency deviates slightly from its > correct value, the count will increment each second by 1 for every 1Hz in > error. By not resetting the counter, as is done in normal frequency > counters, the effect is more of a phase detector than a frequency counter as > any error leads to a cumulatively increasing count. > > A PIC interrupted by the 1 PPS signal then reads this latched figure, and > calculates the error from a nominal mid value of 128. Using a PIC here > allows a calculation to be made for any frequency, not just a multiple of > 256Hz. The direction and magnitude of the error count is then used to > drive a charge pump, which in turn drives the varicap diode of the VCXO. > The effect is to keep the VCXO precisely locked in the long term to the GPS > signal, although in the short term it's instantaneous phase is jittering, > and therefore the frequency is shifting by a Hz or two every second. By > apropriate choice of charge pump R/C values, the jitter can be minimised. > When this source is subsequently divided down to LF, the phase shift is > reduced by the division factor. The PIC includes an initiallisation > routine to force the charge pump to a mid voltage, which is close to that > needed for zero frequency error, so the loop can lock up in less than five > minutes. In comparison, a conventional PLL with 1Hz reference would needs > over 20 minutes even if the capacitor can be precharged AND the two pulse > edges forced into synchronisation by allowing the GPS to reset the divider. > > Results so far are encouraging. The residual phase blip when divided down > from 4.194..MHz to 137kHz is about 10 - 20 degrees over a 1s period, and > when averaged out over a typical 30s signalling period amounts to less than > 1 degree overall. Long term, when compared locally to other frequency > standards available(Caesium, Droitwich, TV Sync) there is no overall phase > shift of the 137kHz signal visible after many hours of monitoring, other > than the propagation effects of the latter two standards themselves. > > A GPS receiver may seem an extravagance, but its value for LF signalling > will be immense ! As well as providing the ultimate long term accuracy for > frequency, by timing PSK signalling to GPS pulses as well, the requirement > for data clock recovery is removed, so gaining many potential dB's in S/N > capability. By defining the starting phase as being at particular time, > even the requirement for differential coding has gone, immediately giving a > factor of two reduction in error rate and removing the threshold effect wrt. > S/N seen with differential coding. > > A GPS receiver also makes an ideal instrument for general purpose frequency > measurements (use it to drive a frequency counter) and a time standard as > well as giving your location ! > > For anyone who wants to have a go and duplicate the design, I will supply a > copy of the circuit, a PCB layout and the PIC software on request. There > may be a bit of a delay however, as the design was only 'frozen' this > weekend and easy-to-read documentation is almost non existant at the moment > ! TAPR still market the Garmin GPS25 receiver module as far as I know, see > their web at www.tapr.org > > (4.194304 MHz was used as it allows a DDS to generate any frequency that is > an exact multiple of 1 Hz without any rounding errors. Which is not the > case for 5 or 10MHz references !) > > Andy G4JNT From andre.kesteloot at ieee.org Tue Jan 29 08:40:05 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:43 2003 Subject: [Lf] LF: PSK31 generation] Message-ID: <3C56A635.59225C03@ieee.org> Johan Bodin wrote: > Dear Jim and the Group > > Jim Moritz wrote: > > > I tried some experiments with a scheme similar to that suggested by Johan - > > The problem with this is that, while the square wave output contains > > essentially no even harmonics, as soon as you change the duty cycle, or the > > relative phase of the two totem pole outputs, a strong second harmonic > > component appears. > > I don't understand this... Perhaps I am missing something, but as far as I can see, > the waveform *will* be symmetrical if the drive to each totem pole has a 50/50 duty > cycle and the modulation is done only by varying the phase between the totem pole > drivers 0 - 180 degrees. For example, with 90 degrees shift it looks like this: > > 0, +1, 0, -1, 0, +1, 0, -1... > > Curiousity made me write a simple program to simulate the signal. The program > generated an audio file containing the difference between two 50/50 square waves. > It starts with the two waves at 180 degrees. The phase difference is then gradually > reduced to zero at the end of the file. > > The file was analysed whith Spectrogram - there was no sign of any even harmonic! > > (This was easier than doing Fourier calculations :-) > > As expected, the level of 3*F approaches that of 1*F when the phase shift > approaches zero. > > As Andy mentioned, the fundamental voltage / phase ratio seems *very* > non-linear. > > 73 > Johan SM6LKM From andre.kesteloot at ieee.org Tue Jan 29 12:52:40 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:43 2003 Subject: [Lf] Tesla Coil as an antenna] Message-ID: <3C56E168.995536E8@ieee.org> Tom Tishken KD4WOV wrote: > Hello, > I have not experimented in a while with my partially built tesla coil, but > has anyone used their Tesla coil as an antenna for ELF or other Freqs? If we > try to use it for 137 KHz how do you determine ERP? > > I had one I was building a few years ago using a 555 timer as an > oscillator with a buffer. Followed by a Darlington pair diving a pair of > power transistors. never got past the primary coil, due to frying the > primary wire with too much current (i.e. too small of a current limiting > resister and too much drive). From andre.kesteloot at ieee.org Tue Jan 29 12:56:56 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:43 2003 Subject: [Lf] re: Tesla Coil as an antenna] Message-ID: <3C56E268.E4FD8AE7@ieee.org> James Moritz wrote: > At 09:14 29/01/2002 -0500, you wrote: > >Hello, > > I have not experimented in a while with my partially built tesla coil, but > >has anyone used their Tesla coil as an antenna for ELF or other Freqs? If we > >try to use it for 137 KHz how do you determine ERP? > Dear Tom, LF group, > > Well, occasionally I have inadvertently used my LF antenna as a Tesla coil > :-) But seriously, The Tesla coil is essentially a helical antenna (see > ON7YD's LF antenna web pages http://www.qsl.net/on7yd/136ant.htm ). So if > it is several metres tall, and you can persuade it to resonate on 136kHz, > it might make a usable LFantenna. Of course, you would want to avoid the > discharges that occur in the normal Tesla coil mode of operation, since > these generate QRM and absorb lots of RF power. > > Cheers, Jim Moritz > 73 de M0BMU From andre.kesteloot at ieee.org Tue Jan 29 18:41:47 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:44 2003 Subject: [Lf] [Fwd: LF: Tesla Coil as an antenna] Message-ID: <3C57333B.26712098@ieee.org> Tom Tishken KD4WOV wrote: > Yes, keeping the sparks from flying is one major concern i was having. I > had a primary coil that resonated very well at 138 KHz, but I never finished > making a secondary coil. Other than a Large globe atop a large secondary > coil, has anyone else found a way to keep it from arcing? > > Second question, should we try to drive it with high voltage (400 to 1200 > volts and very little current) or should we drive it with low voltage (12 to > 24 volts and 10 to 40 amps). The primary coil I was using would withstand 12 > volts and 30 amps, I cooked it when I went to 37 amps. > > Third question, For all you LF antenna guru's. should I use stranded or > solid copper, steel, or aluminum wire. I know each one has good and bad, but > what have you all had better luck with? > > I have thought about keeping the primary coil in mineral oil for heat > dissipation, any suggestions about cooling of the primary? What do you all > use to keep your LF antennas cool? > > -----Original Message----- > From: majordom@post.thorcom.com [mailto:majordom@post.thorcom.com]On > Behalf Of James Moritz > Sent: Tuesday, January 29, 2002 11:05 AM > To: rsgb_lf_group@blacksheep.org > Subject: Re: LF: Tesla Coil as an antenna > > At 09:14 29/01/2002 -0500, you wrote: > >Hello, > > I have not experimented in a while with my partially built tesla coil, > but > >has anyone used their Tesla coil as an antenna for ELF or other Freqs? If > we > >try to use it for 137 KHz how do you determine ERP? > Dear Tom, LF group, > > Well, occasionally I have inadvertently used my LF antenna as a Tesla coil > :-) But seriously, The Tesla coil is essentially a helical antenna (see > ON7YD's LF antenna web pages http://www.qsl.net/on7yd/136ant.htm ). So if > it is several metres tall, and you can persuade it to resonate on 136kHz, > it might make a usable LFantenna. Of course, you would want to avoid the > discharges that occur in the normal Tesla coil mode of operation, since > these generate QRM and absorb lots of RF power. > > Cheers, Jim Moritz > 73 de M0BMU From andre.kesteloot at ieee.org Sun Feb 3 13:51:50 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:44 2003 Subject: [Lf] [Fwd: LF: New Jason record] Message-ID: <3C5D86C5.9F076D50@ieee.org> Alberto di Bene wrote: > On February 2nd, Lyle Koehler, K?LR, has received the 1W RF > beacon of Dexter McIntyre W4DEX at a distance of 1035 miles > (1666 km) operating in Jason mode. Screen shots here : > http://www.gostanly.com/w4dex/ > > Congratulations to both Dex and Lyle ! > > 73 Alberto I2PHD From andre.kesteloot at ieee.org Wed Feb 6 21:07:54 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:44 2003 Subject: [Lf] QRM on 125 kHz ? Message-ID: <3C61E17A.CD7B5A1E@ieee.org> They Want Their ID Chips Now By Julia Scheeres 2:00 a.m. Feb. 6, 2002 PST Meet the Jacobs family: Jeffrey, Leslie and their son, Derek. They're a fairly typical American family, middle class and ambitious. The father is a dentist, the mother is an account executive at an interior design magazine and the 14-year-old son plays jazz and tinkers with computers in his spare time. But one thing may soon make the Jacobses stand out: They could become the first family in the world to be implanted with microchips that contain their personal information. The chip in question, the VeriChip, is similar to the biochips that have been used to identify pets and livestock for years. Made by Applied Digital Solutions (ADS), the VeriChip stores six lines of text and is slightly larger than a grain of rice. It emits a 125-kHz radio frequency signal that can be picked up by a special scanner up to four feet away. The company initially plans to market the chip in the United States as a medical device that would allow hospital workers to simply scan a patient's body in an emergency situation to access their health record. The Jacobses, who live in Boca Raton, Florida, first heard about the microchip in a television news report. "Derek stood up and said, 'I want to be the first kid to be implanted with the chip,'" Leslie Jacobs said. "For the next few days all he did was talk about the VeriChip." Derek, an eighth-grader who became a Microsoft Certified Systems Engineer at age 12, fantasizes about merging humans and machines. Jeffrey Jacobs, who is severely disabled, was interested in the device for health reasons. So Leslie called up Palm Beach-based ADS and offered her family as guinea pigs once the microchip is approved for testing by the FDA. ADS chief technology officer Keith Bolton said he was a bit wary about the family's motives at first, but the Jacobses quickly convinced him they'd be perfect subjects. Since the VeriChip was announced in December, the company has been bombarded with queries from people interested in the device, Bolton said. "Right now we have over 2,000 kids who have e-mailed, wanting to have the chip implanted," he said. "They think it's cool." Derek, for one, dreams of a day when he'll be able log onto his computers or unlock his house and turn on the lights without lifting a finger, functions that British professor Kevin Warwick was able to do in a 1998 experiment with an implanted microchip. Derek was also inspired by Richard Seelig, the company's director of medical applications, who injected two VeriChips into himself after hearing stories of rescue workers at the World Trade Center scrawling their names and Social Security numbers onto their bodies in case they didn't make it out of the rubble alive. "I think it's one more step in the evolution of man and technology," said Derek, who once needed to move into the family room after his electronics equipment crowded his bedroom. "There are endless possibilities for this." (Currently the chip is immutable once the device is injected via a syringe, using local anesthetic. In future applications, the chip may include a GPS receiver and other advanced features, company officials said.) Jeffrey, a 48-year-old cancer survivor, has more practical reasons for wanting the VeriChip. "If something happens to me and there's no one that knows anything about my medical history, any paramedic or hospital worker, if they have the scanner -- which hopefully everyone will have at some point -- will be able to scan all my information," he said. "It could save my life." Leslie, 46, said she was motivated by security concerns. The Sept. 11 terrorist attacks hit close to home: Her family lives in South Florida, where authorities say 14 of the 19 hijackers lived. Her office is a block away from tabloid publisher American Media, where a photo editor died after contracting anthrax. The world would be a safer place if authorities had a tamper-proof way of identifying people, she said. "I have nothing to hide, so I wouldn't mind having the chip for verification," Leslie Jacobs said. "I already have an ID card, so why not have a chip?" Pilots could be chipped and scanned before they entered the cockpit, she suggested, to ensure the person sitting at the controls was indeed an airline employee. Her husband went further, suggesting that violent criminals and known terrorists should be routinely chipped as a matter of policy. The idea of requiring people to be implanted was brought up by Applied Digital Solutions CEO Richard Sullivan in an interview with the Palm Beach Post, in which he suggested microchips be used to track foreigners visiting the United States. (The company has since downplayed his comments.) But an X-Files-type scheme where everyone is forcibly marked and monitored by the government worries both civil libertarians and Christians, who believe new technologies such as biometrics and biochips may be the feared "Mark of the Beast" of Biblical lore that is described in Revelations 13:16: "He also forced everyone, small and great, rich and poor, free and slave, to receive a mark on his right hand or on his forehead, so that no one could buy or sell unless he had the mark, which is the name of the beast or the number of his name." Gary Wohlscheid, the president of The Last Day Ministries -- a group espousing the belief that humanity is on the verge of an apocalyptic showdown between the forces of good and evil -- believes the VeriChip could be this mark. Although the chip is not yet small enough to be injected into the forehead or right hand at the moment, it could be in the future, he said. "Out of all the technologies with potential to be the mark of the beast, the VeriChip has got the best possibility right now," he said. "It's definitely not the final product, but it's a step toward it. Within three to four years, people will be required to use it. Those that reject it will be put to death." Wohlscheid felt so strongly about this possibility that he created a Web page to warn others of the microchip's evil potential. To quell Christians' fears, Bolton, the Jacobses and a theologian recently appeared on the 700 Club, hosted by televangelist Pat Robertson. Privacy expert Richard Smith scoffed at the Jacobses' plans. "Sounds like a publicity stunt and nothing more," he said. "Being chipped today has no value because hospitals and the police don't have the reader units." Although the VeriChip is awaiting FDA approval in the United States, the company recently announced a deal to market the chips to potential kidnap victims living in South America, such as corporate executives. The device could be used to identify abduction victims who are unable to communicate with their rescuers because they are unconscious, drugged or, in a worst-case scenario, dead. The company hopes to get the FDA green light in the next couple of months. When and if that happens, the Jacobses would be among the first subjects to receive the VeriChip, company officials said. ************************ 73 Andr? N4ICK From andre.kesteloot at ieee.org Fri Feb 8 17:42:15 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:44 2003 Subject: [Lf] Mitnick's ham license ? Message-ID: <3C645447.433D4E63@ieee.org> Mitnick to Plead for Ham License By Michelle Delio 2:00 a.m. Feb. 8, 2002 PST Hacker Kevin Mitnick will soon be back in court, this time facing charges that may require him to testify on whether his bad reputation is solely a media-created myth. The Federal Communications Commission filed an action in late December to revoke Mitnick's amateur radio license. The commission does not charge (PDF) that Mitnick, who spent four-and-a-half years behind bars on various hacking charges, has violated any amateur radio rules or regulations. It is rather that the court fears, based on his past actions, he might violate those rules in the future. Mitnick has wavered on whether he could afford to contest the FCC's charges, but late last week he opted to hire a lawyer, and said he intends to fight for as long as his finances permit. In order to retain his license, Mitnick now faces a legal battle that will most likely require him to admit to an FCC court that he was a very bad man, according to legal sources who said that Mitnick's "attitude" may be the determining factor in whether he wins this case. "He's been high-profile recently, and in some circles he has left the impression that he is unrepentant, that he sees himself as a pawn in the government's war against computer criminals," said an FCC source, speaking on condition of anonymity. FCC representatives refused to comment officially on Mitnick's case. Mitnick, since his release from prison last January, has publicly said he is not guilty of every crime that the media and the government have accused him of perpetrating. "But I have never, ever, said that I was totally, or even mostly, a complete innocent," Mitnick said. Clouding the issue is the complexity of Mitnick's case. In trial transcripts, the government charges Mitnick with crimes resulting in financial damage of widely varying amounts -- anywhere from $1.5 million to $300 million. Even the lowest figure has been disputed by computer security experts. "It's difficult to know exactly what Kevin did in the way of damages," said Lauren Colby, the lawyer who is representing Mitnick in the FCC case. "Frankly, he doesn't know how much damage he caused and neither does the government. The critical point here is that he never intended to do damage." The current problem is further complicated by Mitnick's decision to accept a plea bargain that would release him from jail in a specified amount of time, as opposed to taking his chances with a jury. He based that choice on the advice of his lawyer at the time and after being held in prison pending trial for four years. "I saw it as a way of acknowledging my guilt, as well as a way out of what seemed to be a never-ending waiting game," Mitnick said. "I think the vast majority of people placed in my position would have done the same." Colby believes the outcome of the FCC case will depend on Mitnick's attitude. "He needs to make it clear he has not denied that he committed crimes," Colby said. "He also needs to prove to the FCC that he will not repeat his past actions, either because he has discovered the error of his ways or because he doesn't want to go back to jail. It doesn't much matter why he's changed, the point that he needs to make is that he has changed." Mitnick said that he had hoped to resume a normal life and use his technology skills for positive purposes after his release from prison. In the past year, he has testified before the U.S. Senate and industry groups on security. And he is authoring a book on how to make information secure against social engineering hacks. The amateur radio community appears to be split over whether Mitnick should retain his license, according to Bennett Kobb, a journalist who covers communications and the author of Wireless Spectrum Finder, a guidebook for amateur radio enthusiasts. "Kevin is a high-profile 'bad guy,' and so I suspect a lot of people in the amateur radio community would applaud if his license was pulled," Kobb said. "A lot of people only know what they have read in the media about Kevin." Mitnick's friends have created a legal defense fund to help defray the costs of his latest court battle. From hfeinstein at cox.rr.com Sat Feb 9 01:49:52 2002 From: hfeinstein at cox.rr.com (Hal) Date: Thu Jul 3 13:44:45 2003 Subject: [Lf] Re: Mitnick's ham license ? In-Reply-To: <3C645447.433D4E63@ieee.org> Message-ID: <4.3.2.7.2.20020209011504.00b62470@pop-server> The government conducted a wide scale witch hunt against Mitnick and now the FCC seems to be infected by the same loss of perspective. He is not innocent. Nor is he the computer savvy master criminal bent on destruction made out by the government. Usually the commission's decisions are appropriate and proportional but it seems, at least in this case, not to be able to tell the difference between fact and fantasy. Nor is its act proportionate. This agency sets the market conditions for emerging communications technologies and fortunes are made or lost on its decisions. One hopes they see more clearly on these matters then they demonstrate in the Mitnick case. Hal At 05:42 PM 2/8/02 -0500, Andre Kesteloot wrote: >Mitnick to Plead for Ham License >By Michelle Delio >2:00 a.m. Feb. 8, 2002 PST >Hacker Kevin Mitnick will soon be back in court, this time facing >charges >that may require him to testify on whether his bad reputation is solely >a >media-created myth. > >The Federal Communications Commission filed an action in late December >to >revoke Mitnick's amateur radio license. The commission does not charge >(PDF) that Mitnick, who spent four-and-a-half years behind bars on >various >hacking charges, has violated any amateur radio rules or regulations. It > >is rather that the court fears, based on his past actions, he might >violate those rules in the future. > >Mitnick has wavered on whether he could afford to contest the FCC's >charges, but late last week he opted to hire a lawyer, and said he >intends >to fight for as long as his finances permit. > >In order to retain his license, Mitnick now faces a legal battle that >will >most likely require him to admit to an FCC court that he was a very bad >man, according to legal sources who said that Mitnick's "attitude" may >be >the determining factor in whether he wins this case. > >"He's been high-profile recently, and in some circles he has left the >impression that he is unrepentant, that he sees himself as a pawn in the > >government's war against computer criminals," said an FCC source, >speaking >on condition of anonymity. FCC representatives refused to comment >officially on Mitnick's case. > >Mitnick, since his release from prison last January, has publicly said >he >is not guilty of every crime that the media and the government have >accused him of perpetrating. > >"But I have never, ever, said that I was totally, or even mostly, a >complete innocent," Mitnick said. > >Clouding the issue is the complexity of Mitnick's case. In trial >transcripts, the government charges Mitnick with crimes resulting in >financial damage of widely varying amounts -- anywhere from $1.5 million > >to $300 million. Even the lowest figure has been disputed by computer >security experts. > >"It's difficult to know exactly what Kevin did in the way of damages," >said Lauren Colby, the lawyer who is representing Mitnick in the FCC >case. >"Frankly, he doesn't know how much damage he caused and neither does the > >government. The critical point here is that he never intended to do >damage." > >The current problem is further complicated by Mitnick's decision to >accept >a plea bargain that would release him from jail in a specified amount of > >time, as opposed to taking his chances with a jury. He based that choice > >on the advice of his lawyer at the time and after being held in prison >pending trial for four years. > >"I saw it as a way of acknowledging my guilt, as well as a way out of >what >seemed to be a never-ending waiting game," Mitnick said. "I think the >vast >majority of people placed in my position would have done the same." > >Colby believes the outcome of the FCC case will depend on Mitnick's >attitude. > >"He needs to make it clear he has not denied that he committed crimes," >Colby said. "He also needs to prove to the FCC that he will not repeat >his >past actions, either because he has discovered the error of his ways or >because he doesn't want to go back to jail. It doesn't much matter why >he's changed, the point that he needs to make is that he has changed." > >Mitnick said that he had hoped to resume a normal life and use his >technology skills for positive purposes after his release from prison. >In >the past year, he has testified before the U.S. Senate and industry >groups >on security. And he is authoring a book on how to make information >secure >against social engineering hacks. > >The amateur radio community appears to be split over whether Mitnick >should retain his license, according to Bennett Kobb, a journalist who >covers communications and the author of Wireless Spectrum Finder, a >guidebook for amateur radio enthusiasts. > >"Kevin is a high-profile 'bad guy,' and so I suspect a lot of people in >the amateur radio community would applaud if his license was pulled," >Kobb >said. "A lot of people only know what they have read in the media about >Kevin." > >Mitnick's friends have created a legal defense fund to help defray the >costs of his latest court battle. > > > > > >_______________________________________________ >Tacos mailing list >Tacos@amrad.org >http://www.amrad.org/mailman/listinfo/tacos From andre.kesteloot at ieee.org Tue Feb 12 09:40:49 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:46 2003 Subject: [Lf] GPS Locked PSK Message-ID: <3C692971.2DC6E56F@ieee.org> Talbot Andrew wrote: > I am now in a position to transmit GPS locked and timed PSK signals using > the high power transmitter giving around 100mW ERP - at least it should be > that power when the weather eventually stops raining. A lower power Tx is > also available for microwatt ERP levels. > Software driving the DDS module can generate any of these types of PSK data > : > > Pure binary code, specified as Hex or by its 1/0 sequence. > ASCII - non differentially coded in the Varicode alphabet as used > for PSK31. > As above, but differentially coded to remove the phase ambiguity but > giving 2* error rate. > CW representation, where key down = 0 deg, key up = 180 deg > - Ideal for visual decoding on a time / phase plot but less > efficient than varicode. > > Data rate can have any bit period that is an exact multiple of one second, > and timed to UTC pulses. For decoding purposes it may be convenient to > define a time reference, such as the hour, where the data sequence starts; > and also to define the start polarity at that point. > > Frequency using the GPS locked reference can be any exact multiple of 1/1024 > Hz (so all 1Hz values are possible) but could have up to 20 degrees of > phase jitter on it over a period of a few seconds. The effect of this is to > give 1Hz sidebands at a level of -40dB. A more short term stable source > can generate Caesium, MSF or TV sync locked frequencies that are based on > 6.5536 MHz / 2^32, so exact Hz multiples are available every 25Hz. I prefer > not to have the Cs tube runing for extended periods as it has got to last a > lifetime and I don't know how many hours are left in the tube. > > So if anyone is ready with vectorscopes, PSK demodulators etc......... > > Andy G4JNT > > -- From andre.kesteloot at ieee.org Wed Feb 13 18:57:40 2002 From: andre.kesteloot at ieee.org (Andre Kesteloot) Date: Thu Jul 3 13:44:46 2003 Subject: [Lf] Class E stages Message-ID: <3C6AFD74.1EE6C233@ieee.org> well worth looking at ! 73 Andr? http://www.alan.melia.btinternet.co.uk/classepa.htm#Class E Power Amplifier Design From g3wkl at btinternet.com Thu Feb 14 15:09:59 2002 From: g3wkl at btinternet.com (John W Gould) Date: Thu Jul 3 13:44:46 2003 Subject: [Lf] RSGB HF & IOTA International Convention 2002: Call for Papers Message-ID: You will be aware through the excellent articles in the AMRAD Newsletter by Andre', N4ICK, this annual convention has been one of the foremost occasions in Europe where amateurs interested in LF have met and exchanged views and shared their knowledge on LF operating, technical and experimental matters. Indeed AMRAD has been well represented by Andre' who has been very active in providing a valuable US input to the proceedings. After taking a back seat last year on account of other commitments I am chairing the organising committee this year. This will give me an even better opportunity to improve the event further for those interested in LF. I know that Andre's yardstick of success is to get LF into the title of the convention! As a part of the initial preparation I am issuing a copy of the announcement that will appear in the March RadCom, the RSGB, CDXC and IOTA websites, onto this list. -- CALL FOR PAPERS Papers are invited for the RSGB International HF and IOTA Convention to be held at the Beaumont Convention Centre, Old Windsor, Berkshire over the weekend 11th - 13th October 2002. The Convention covers DXing and technical topics that relate to amateur bands from (and including) 50MHz to 73kHz. This year we will be particularly interested to consider topics of interest to the new Foundation Licence holders. If you have an interesting idea and wish to be considered as a speaker please submit a brief abstract on the subject matter to the Chairman of the HF Convention sub-committee via e-mail to HFC2002.Chairman@rsgb.org.uk or by post to RSGB HQ. -- 73 John, G3WKL From andre.kesteloot at verizon.net Sun Feb 17 10:04:46 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:46 2003 Subject: [Lf] 162 and 183 KHz BC in NC] Message-ID: <3C6FC68D.B7184E47@verizon.net> "Dexter McIntyre, W4DEX" wrote: > I tried for several hours to copy W1TAG's WOLF signal on 177.8 KHz with > no success. When I put the receiver in wide IF mode I realized why. > The LF BC stations were booming in. I have uploaded .wav files of the > 162 and 183 KHz stations at: > > http://www.gostanly.com/w4dex/BC/162KHz.wav (.941 MB) > > http://www.gostanly.com/w4dex/BC/183KHz.wav (1.8 MB) > > BC on 177 and 153 were coming also but not as well. > > Dexter From andre.kesteloot at verizon.net Tue Feb 19 14:05:17 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:46 2003 Subject: [Lf] Vectorscope Message-ID: <3C72A1ED.F0F138D1@verizon.net> Jim Moritz Vectorscope scematic is now available at http://www.wireless.org.uk/XY.htm Andr? N4ICK From andre.kesteloot at verizon.net Tue Feb 26 18:31:04 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:46 2003 Subject: [Lf] ADSL QRM ? Message-ID: <3C7C1AB8.4B993F44@verizon.net> for information on interference from ADSL, look up http://www.ce-mag.com/archive/02/01/newsline.html 73 Andr? From andre.kesteloot at verizon.net Mon Mar 4 08:44:06 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:47 2003 Subject: [Lf] [Fwd: LF: Noise Cancelling RX antennas] Message-ID: <3C837A26.3F2241AF@verizon.net> James Moritz wrote: > Dear LF Group, > > As I mentioned a few weeks ago, I have been having problems with local > mains-generated QRM from an unknown source which made it impossible to copy > the weaker signals on the band. Over the weekend I tried out a noise > cancelling system which seems to more or less solve the problem. > > I first tried using various antennas I already had as "signal" and "noise" > antennas, with the HF type phasing circuits that have been around for a > while. I found that it was possible to null the noise, but the bandwidth of > the null was at best a few 100 Hz; changing frequency or re-tuning the > antenna meant complete re-adjustment of the phasing network was required, > which was not easy because the noise level varies rapidly and makes it > hard to tell if the null has been found. So the system was not very practical. > > Thinking about it, the problem compared to HF is that the LF antennas and > phasing networks are relatively very narrow band, and so phase and > amplitude of the signals changes rapidly with frequency. In order to get a > null, the noise signals from the 2 antennas must be equal in amplitude and > 180degrees out of phase when the signals are combined, therefore a null is > obtained only over a narrow bandwidth. I decided the solution would be to > use two identical, matched, loop antennas with fairly wide bandwidth, in > combination with differential phase shift networks (similar to those used > for the LO in a phasing SSB exciter), so that the whole system has a > reasonably constant relative phase over a considerable bandwidth. > > I made 2 tuned loop antennas with 2m sides from 15mm copper water pipe. > These have low noise pre-amps and a bandwidth of about 30kHz, and by > themselves have more than adequate sensitivity to hear the external noise > in a quiet band. One is located at the end of my garden nearest the noise > source, while the "signal" antenna is positioned at the opposite end of the > garden. Both loops are oriented to null the Loran signal form Lessay, which > at the same time gives quite good Europe/NA coverage at my QTH. The signals > are each passed through RC phase shift networks tuned by a dual gang pot, > arranged so that as the phase shift of one increases, the other decreases. > The phase shift networks are buffered to prevent loading effects. The > relative phase can be varied over a range of about +/-120degrees, and a > transformer and switch gives a further 0/180degree shift means any phase > shift can be nulled. The "noise" antenna signal also passes through a > variable attenuator, and the two signals are combined in a transformer and > fed to the RX. > > In operation, once the null is found it seems to be quite stable, and > covers the whole amateur band without adjustment. While operating, there > was no noticeable interaction with the TX vertical, although one of the > loops is directly under it (the TX ant is de-tuned on receive). Without > noise cancelling, the normal mains noise is about 10-15dB above the natural > band noise, with peaks up to 30 - 40 dB. After nulling, the normal mains > noise is inaudible, while the peaks can still be heard but are obviously > much weaker. The system is still in the breadboard phase, but is certainly > a huge improvement over the situation before - it is entertaining to switch > the noise antenna on and off and hear the change in noise level! > > Cheers, Jim Moritz > 73 de M0BMU From andre.kesteloot at verizon.net Wed Mar 13 10:19:11 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:47 2003 Subject: [Lf] [Fwd: LF: Demodulator program for the W & G Pegelmesse] Message-ID: <3C8F6DEF.D6899B27@verizon.net> Alberto di Bene wrote: > Many LF enthusiasts have a Selective Level Meter, generally > made by Wandel & Golterman. Some of these units have a > demodulated output, others don't, instead providing a last > IF output at 10 kHz on the rear panel. > > For this last kind of equipment I have written a sort of last IF > stage in software, which accepts as input a frequency between > 40 and 20000 Hz, and extracts the AM, USB or LSB modulation > it may have, playing it through the PC sound card. > > The program sports also a graphical Phase Meter, which works > only when AM is selected, and measures the incoming carrier > phase referred to the program 'BFO' phase. It can be used for > a very superfine tuning. A frequency difference of 1 Hz between > the incoming signal and the BFO produces a whole revolution > every second, so frequency differences of 10 mHz are easily > appreciated. > > The program does not touch the audio mixer, so it's up to the user > to set it correctly. Basically you have to set the Recording panel > so that only Line In is selected, and the Playback panel so that > only Wave is selected. Make sure that Line In is *deselected* > for Playback. > Of course you will have to connect the 10 kHz output of your > Selective Level Meter to the Line In of the sound card. > > The program has a very serious problem, as the played audio lags > the input by almost a second, so tuning is quite difficult. > This is due to the processing of the signal, and to the MME system > of Windows. There are ways to improve this, and maybe I will > pursue this, depending on my spare time and the acceptance > of the program. > > Bear in mind that this is just a first cut, more an alpha version than > a beta, so do not have excessive expectations.... I wrote it more > as an exercise, using some routines I had already written for > the version 0.93 of Jason (to be released). > Of course any criticism, suggestions, bug reports are welcome. > > The program can be downloaded from : > http://www.weaksignals.com/bin/radiopak_090.exe > > 73 Alberto I2PHD From fgentges at mindspring.com Wed Mar 13 20:41:41 2002 From: fgentges at mindspring.com (Frank Gentges =?iso-8859-1?Q?K=D8BRA?=) Date: Thu Jul 3 13:44:47 2003 Subject: [Lf] [Fwd: LF: Demodulator program for the W & G Pegelmesse] In-Reply-To: <3C8F6DEF.D6899B27@verizon.net> Message-ID: <5.0.2.1.0.20020313203728.0298bdd0@pop.mindspring.com> We need to try this out. The last IF of the RX320 is 12 kHz so this software might have something to add. I assume it needs a full duplex sound system. But for now I must head out the door to take care of more mundane business for a week. Frank K0BRA At 10:19 AM 3/13/02 -0500, Andre Kesteloot wrote: >Alberto di Bene wrote: > > > Many LF enthusiasts have a Selective Level Meter, generally > > made by Wandel & Golterman. Some of these units have a > > demodulated output, others don't, instead providing a last > > IF output at 10 kHz on the rear panel. > > > > For this last kind of equipment I have written a sort of last IF > > stage in software, which accepts as input a frequency between > > 40 and 20000 Hz, and extracts the AM, USB or LSB modulation > > it may have, playing it through the PC sound card. > > > > The program sports also a graphical Phase Meter, which works > > only when AM is selected, and measures the incoming carrier > > phase referred to the program 'BFO' phase. It can be used for > > a very superfine tuning. A frequency difference of 1 Hz between > > the incoming signal and the BFO produces a whole revolution > > every second, so frequency differences of 10 mHz are easily > > appreciated. > > > > The program does not touch the audio mixer, so it's up to the user > > to set it correctly. Basically you have to set the Recording panel > > so that only Line In is selected, and the Playback panel so that > > only Wave is selected. Make sure that Line In is *deselected* > > for Playback. > > Of course you will have to connect the 10 kHz output of your > > Selective Level Meter to the Line In of the sound card. > > > > The program has a very serious problem, as the played audio lags > > the input by almost a second, so tuning is quite difficult. > > This is due to the processing of the signal, and to the MME system > > of Windows. There are ways to improve this, and maybe I will > > pursue this, depending on my spare time and the acceptance > > of the program. > > > > Bear in mind that this is just a first cut, more an alpha version than > > a beta, so do not have excessive expectations.... I wrote it more > > as an exercise, using some routines I had already written for > > the version 0.93 of Jason (to be released). > > Of course any criticism, suggestions, bug reports are welcome. > > > > The program can be downloaded from : > > http://www.weaksignals.com/bin/radiopak_090.exe > > > > 73 Alberto I2PHD > > > > >_______________________________________________ >lf mailing list >lf@amrad.org >http://www.amrad.org/mailman/listinfo/lf Frank Gentges K?BRA LF web site at From dibene at usa.net Thu Mar 14 14:56:59 2002 From: dibene at usa.net (Alberto di Bene) Date: Thu Jul 3 13:44:47 2003 Subject: [Lf] If you have downloaded PHD Radio... Message-ID: <3C90AC2B.898F7C6@usa.net> If you have downloaded PHD Radio 0.90, please download 0.91 V 0.90 has been removed from the Web site.It contained a couple of bugs, introduced during some experiments performed just minutes before uploading it. Then I forgot to undo the changes done for the tests... http://www.weaksignals.com/bin/radiopak_091.exe Sorry for the inconvenience. 73 Alberto I2PHD From andre.kesteloot at verizon.net Fri Mar 15 20:50:46 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:47 2003 Subject: [Lf] Re: LF Transmitting References: <20020315.194009.-838905.1.kb9mbn@juno.com> Message-ID: <3C92A4F6.5038C205@verizon.net> kb9mbn@juno.com wrote: > Hi my name is Myron and I have been enjoying the information on > the AMRAD web site. I was reading about the part where the last > Alexanderson alternator was used as a transmitter. I remember > reading a little about alternators used as transmitters in the early > days of radio. yes there was a whole article about this, including an alternator _receiver_ in the latest issue of the RSGB magazine RadCom > > The question is can a automotive alternator be used for a transmitter > or are they not usable for transmitting because of the way the coils are > wound? no idea > > I was just wondering if anybody has thought of this idea. I am thinking > of > getting into LW experimenting good , in fact excellent > but with working and two small kids it gets > hard to get projects started. why don't you just start by building a simple small transmitter? Look at the projects described in the RSGB's excellent book "The LF Experimenter's Handbook" You can build a Tx with just a couple of ICs plus a MosFET as the output stage. > One more thing, what is the success if any with monitoring LW near towns > and especially near medium wave radio stations?Thanks we do some of our most successful reception in downtown Oakton, near Vienna Virginia, with the antenna (a active dipole -see QST last October (?) for a description of K0BRA's AMRAD antenna) on the roof of a building full of computers :-) Keep in touch and let me know of your progress 73 Andr? N4ICK From andre.kesteloot at verizon.net Sat Mar 16 07:58:48 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:48 2003 Subject: [Lf] HAARP Tests Message-ID: <3C934187.9CB475A0@verizon.net> The HAARP project in Alaska will be performing their VLF injection campaign from March 15-28th. Transmissions will be on frequencies around 3200, 3300, and 5800 kHz. Transmissions will start at 1900 Alaska time (0400 UTC) and lasting about 10 hours. What kind of signals to look out for: 3.2 MHz: 12.5 Hz on/off keying 50 % duty cycle 3.3 MHz and 5.8 MHz: sinusoidal modulation with the following frequencies; 1225 Hz, 1875 Hz, 2125 Hz, 2375 Hz, 3365 Hz. At these two frequencies, there will also be chirp transmissions. The HAARP website is: http://server5550.itd.nrl.navy.mil/projects/haarp/ Regards & Best Wishes Roy MM0LOS From andre.kesteloot at verizon.net Sat Mar 16 18:20:56 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:48 2003 Subject: [Lf] [Fwd: LF: Best receiver for LF.] Message-ID: <3C93D358.62D5922B@verizon.net> Giulio Scaroni wrote: > Thank for all the station that has answered me with private e-mail for > my question on best LF receiver.I have bought last week end at ham > fest here an EDK300 by RFT, is a very good receiver tunable from 14 > Khz to 30 Mhz, very very good stability from an OCXO at 10 Mhz, but > not better than my IC775, the Icom have a better phase noise becouse > its use the DDS, in EDK, the design is like Racal little older, so PLL > from late 80 is little noisy.Also i have bought a W&G SPM-12, and also > this unit is very well working on LF, so at the end, after many test, > not big difference from all the equipment, also the W&G, with the 25 > Hz filter is very good in QRSS (but not good stability, the OL is not > phase loocked).The last is my IC 738 with an external DBM Mini Circuit > mixer and preselector, not worse, not better than all the other here, > with my short antenna, may be that in Mantova with big antenna the > history may be different!!So, after this test, i dont know if is > really good buy a receiver designed for LF, when a good HF radio with > external converter do the same job!!But is also the spirit of our > hobby testing all the equipment, for find the better solution at less > price.73 to all IK2DED Giulio. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://atanasoff.rf.org/pipermail/lf/attachments/20020316/81640b05/attachment.html From hfeinstein at cox.rr.com Sun Mar 17 08:30:26 2002 From: hfeinstein at cox.rr.com (Hal) Date: Thu Jul 3 13:44:48 2003 Subject: [Lf] Re: HAARP Tests In-Reply-To: <3C934187.9CB475A0@verizon.net> Message-ID: <4.3.2.7.2.20020317082818.00b72b10@pop-server> This is a very well designed web site and is very informative too. However, there is no mention of the blue aliens which is disappointing. H At 07:58 AM 3/16/02 -0500, Andre Kesteloot wrote: >The HAARP project in Alaska will be performing their VLF injection >campaign >from March 15-28th. Transmissions will be on frequencies around 3200, >3300, >and 5800 kHz. Transmissions will start at 1900 Alaska time (0400 UTC) >and >lasting about 10 hours. > >What kind of signals to look out for: > >3.2 MHz: 12.5 Hz on/off keying 50 % duty cycle >3.3 MHz and 5.8 MHz: sinusoidal modulation with the following >frequencies; >1225 Hz, 1875 Hz, 2125 Hz, 2375 Hz, 3365 Hz. At these two frequencies, >there >will also be chirp transmissions. > >The HAARP website is: >http://server5550.itd.nrl.navy.mil/projects/haarp/ >Regards & Best Wishes >Roy >MM0LOS > > > > >_______________________________________________ >Tacos mailing list >Tacos@amrad.org >http://www.amrad.org/mailman/listinfo/tacos From prinaldo at mindspring.com Mon Mar 18 07:43:01 2002 From: prinaldo at mindspring.com (Paul L Rinaldo) Date: Thu Jul 3 13:44:48 2003 Subject: [Lf] QST Message-ID: <3.0.32.20020318074214.006b8b48@pop.mindspring.com> Gang, Frank Gentges, K0BRA and Steve Ratzlaff, AA7U, authored an article entitled "AMRAD Low Frequency Upconverter," which appears on pages 34-39 of the April 2002 edition of QST. Congratulations. 73, Paul, W4RI From andre.kesteloot at verizon.net Tue Mar 19 12:19:06 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:49 2003 Subject: [Lf] RU6LA QRV from KN97LN March 30-31, 2002] Message-ID: <3C97730A.FD9D70F5@verizon.net> "'Geri' Kinzel, DK8KW" wrote: > Hello LF Group, > > I got an e-mail from Ed, RU6LA, who has a license on hand for 136 kHz > operation. > > He and UA6LV are preparing the first Russian DX-pedition on LF, they intend > to be QRV during the WPX contest weekend March 30-31, 2002, using a 135 m > high antenna tower with 100 Watts output. His QTH is near Taganrog/Russia, > the locator is KN92LN, which is approximately 2100 km from my QTH. > > Ed will try to be QRV in QRSS around 137.700 kHz (3 second dots). More > details about his operation schedule and possible QSX frequencies will be > available later. > > Looking forward to some "firsts"! > > Vy 73 > > Geri, DK8KW (W1KW) From andre.kesteloot at verizon.net Tue Mar 19 20:15:01 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:49 2003 Subject: [Lf] The ultimate in stealth antennas ... Message-ID: <3C97E295.D15F2F30@verizon.net> The ultimate in stealth antennas ... http://www.alandick.com/pages/enviro/enviro.html 73 Andr? N4ICK From andre.kesteloot at verizon.net Wed Mar 20 22:12:51 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:49 2003 Subject: [Lf] Re: LF and NB References: Message-ID: <3C994FB3.CCB053EA@verizon.net> Paul.Katz@bakerbotts.com wrote: > I have a Squires-Sanders SS-1R I am interested in using with the LF > converter featured in QST for April 2002. The SS-1R has provision for noise > blanking but I don't have the noise blanker for it. I was interested in > adapting your noise blanker to use with the SS-1R. The SS-1R has a wideband > IF of 5-5.5 MHz and a blankable IF of 1 MHz. > > 73, Paul W5NTQ ****************************************** Hello Paul, Thanks for your interest in the AMRAD LF Up-converter. In our experience, at LF one of the uppermost noise problems can be mains-synchronous interference, often produced by light dimmers and such. These pulses essentially overload the receiver's AGC. Hence one prefers to get rid of the noise before it enters the receiver, rather than at the IF level. One way to dispose of this 60HZ QRM is to create sharp pulses synchronized to the 60 Hz mains. Then, further shaping circuits allow for (a) adjustable broadening of these pulses and (b) variable delaying in time. These pulses are then applied to a double-balanced mixer connected between the antenna and the up-converter. Looking at the display of the output of the receiver on a PC screen (using a program such as Spectran or Argo, for instance) it is now easy to adjust the width and phase of the pulses to ground the receiver's input during the occurrence of these pulses. Hope this helps, and good hunting on LF. 73 Andr? N4ICK From andre.kesteloot at verizon.net Sat Mar 23 09:27:09 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:49 2003 Subject: [Lf] [Fwd: LF: ZL6QH seen in Massachusetts] Message-ID: <3C9C90BD.D4A6D7A2@verizon.net> John Andrews wrote: > I know this doesn't set any new distance records, but I appear to have > captured two of the DFCW "Q's" from ZL6QH this morning, on 137.789 kHz. The > screen shot may be seen at: > http://webpages.charter.net/w1tag/files/ZL6QH.jpg > > The shot covers the 1000 - 1100 UTC time period, with the reception > occurring around 1030. This is about a half hour before my local sunrise. An > attempt to record the session on another computer with a 60 sec/dot setting > failed when the computer locked up overnight. The 120 second screen smears > the consecutive characters, so each of the long lines is actually two > "dashes." > > The receiving location is in Holden, Massachusetts, grid square FN42ch. > Coordinates are 42d 19m 12s N and 71d 49m 43s W. An Icom R75 receiver with a > 12 turn loop was used. > > I'll be out of email contact for a day or so. > > John Andrews, W1TAG From andre.kesteloot at verizon.net Sat Mar 23 09:32:08 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:49 2003 Subject: [Lf] [ZL6QH 137khz test received in North Carolina] Message-ID: <3C9C91E7.95849AAB@verizon.net> "Dexter McIntyre, W4DEX" wrote: > Best Q received just after 0900 posted at: > > http://www.gostanly.com/w4dex/Argo/ZL6QH/ZL6QH23mar020930.jpg > > More screen shots at this directory: > > http://www.gostanly.com/w4dex/Argo/ZL6QH/ > > ARGO screen time is UTC. > > My thanks to ZL2CA and the Quartz Hill group for their efforts. > > Dexter, W4DEX From andre.kesteloot at verizon.net Wed Mar 27 14:35:10 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:49 2003 Subject: [Lf] Heathkit schematics Message-ID: <3CA21EED.689C1492@verizon.net> http://www.circuitarchive.co.uk/heath.htm From andre.kesteloot at verizon.net Thu Mar 28 10:33:55 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:50 2003 Subject: [Lf] [Fwd: LF: Jason V0.93] Message-ID: <3CA337E3.C52EB3F7@verizon.net> Alberto di Bene wrote: > Hello all, > Jason 0.93 has been just uploaded to the weaksignals Web site. > The signalling format is compatible with 0.92 > The main changes are : > > - A different demodulation method (zero IF) has been used, which makes > unnecessary the Low Speed mode. Now the program works ok on > a 150 MHz Pentium, with no compromises. > > - The program now remembers from session to session the various > settings > > - Tweaking of the decode routine, with (maybe) a fraction of a dB in > decoding gain. > > - Minor adjustments to the code and bug fixes. > > To download it : http://www.weaksignals.com > > Reports are welcome. > > 73 Alberto I2PHD From andre.kesteloot at verizon.net Fri Mar 29 16:49:11 2002 From: andre.kesteloot at verizon.net (Andre Kesteloot) Date: Thu Jul 3 13:44:50 2003 Subject: [Lf] [Fwd: LF: loop resonant frequency] Message-ID: <3CA4E157.BC28ECA1@verizon.net> Larry Kayser wrote: > Tuning a large loop to resonance and measuring the loop inductance is easy > without any instruments but a receiver and a calculator. > > Just couple to the loop with a toroid and put a silver mica bank of > capacitors in series with the loop. Feed a receiver and tune for peak in > the noise. Once you find a noise peak the standard resonance formula with > the known capacitance will tell you the inductance of the loop. To check > it out, and what I did here, was to setup a resonance on 138.83 and another > on 135.922. The mathematics works very precisely down to less than 30 pf > ambiguity, in my case just about half a kHz. The difference is a small > plug in bunch of small value silver mica capacitors. > > Larry > VA3LK > > I did not originate this, Bill, VE2IQ did many years ago.