AMRAD LF Receiver Page

Receivers can be:

• Commercially available units covering LF. Sandy, WB5MMB, talked Andre', N4ICK out of his RBA-1, built for the US Navy in 1942. It weighs a mere 95 lbs. This RBA-1 was able to hear the transmission from SAQ, Grimeton Sweden. It really proved it is still a performer.
• Some Icom and Kenwood receivers also cover down to 100 Khz.
• Commercial receivers. Two members have Cubic R-3030 receivers and they perform superbly on LF and VLF.
• Short wave receivers preceded by a converter, which upconverts the LF band to a SW band.
• Designed from scratch, especially for the job. AMRAD is looking at designing one now.
• Modified commercial short wave receivers such as the TenTec RX-320.
• Regardless of the receiver, the noise at LF can be a problem. An LF noise blanker can be a real asset.

UpConverter

• An upconverter converts the LF band up to the HF range so a high performance HF receiver that does not receive LF can be used to receive LF.
• AMRAD has an upconverter design that was published in the April 2002 QSt. Performance is really good. Grab this QST and check it out.

TenTec RX-320

• Modification has proved simple and effective by AMRAD making high performance available to those interested in trying LF.
• Information on our modification is provided here.

CUBIC R-3030/R3080

• Several AMRAD members were fortunate to have obtained surplus Cubic R-3030 receivers.
• This receiver goes down to 5 kHz and works really well on VLF and LF. If you run across one at a hamfest, by all means, take a hard look at it.
• We have obtained permission of Cubic to put the whole manual up for download. It is a great lesson in modern receiver design and look at the details on how they make it work on VLF and LF. The manual file is Acrobat and is almost 6 megs in size. Download here.

Rycom 2171/R1307A

• Several other AMRAD members have obtained the vacuum tube selective voltmeter made by Rycom and have had good results.
• The manual can be downloaded and you can see if it fits your version. Download here.

LF Noise Blanker

• Andre' Kesteloot, N4ICK has built a noise blanker that works well against AC power line noise.
• A challenge to LF amateurs is working in the presence of thunderstorm static. We call this sferics.
• AMRAD is developing a noise blanker that works against both AC power line noise and sferics. We hope to have a working prototype soon that can be built by others. Stay tuned.