Upcoming Meetings
March 20, 2014, 7:30pm NOTE: THIRD THURSDAY - "An Amateur-Radio Solution to Frequency-Hopping Synchronization" André Kesteloot N4ICK and Maitland Bottoms AA4HS will jointly present a creative approach to the spread spectrum challenge posed by André in his December 2013 presentation. Dolley Madison Library, McLean, VA. Dolley Madison Library, McLean, VA.
April 17, 2014, 7:30pm NOTE: THIRD THURSDAY - "Fun With Electric Motors" Karl Berger, W4KRL will take us back to the 19th Century to explore the fundamentals of direct current motors. Karl will demonstrate an open frame dc commutator motor that has slip rings connected to one rotor winding. This enables observing the rotor voltage on an oscilloscope. We return to the modern era and do all the motor control with an Arduino using Pulse Width Modulated power supplies and Hall-effect current sensors. We will run the motor to synchronous speed and energize the motor with ac, making it run as a synchronous converter to rectify ac by mechanical means. Dolley Madison Library, McLean, VA.
Recent Meetings
February 13 - cancelled by snow
January 9 - "Rubidium Frequency Standards and Teardown" Frank Gentges, KØBRA, briefed us on rubidium frequency standards. Then, upholding a proud AMRAD tradition, he toredown a Frequency Electronics type FE-5682A standard.
December 12 - Annual Business Meeting. Directors elected for 2014-2015: Paul Rinaldo, W4RI, Frank Gentges, KØBRA, Karl Berger, W4KRL
André Kesteloot, N4ICK, demonstrated an Arduino-based "Spread-Spectrum Frequency-Hopping Transmitter Module" that he has developed. André needs ideas for the receiver side of the system. AMRAD members engaged in a lively discussion about how the receiver could detect and lock on to the transmitted signal.
- November 21 - Bill Liles, NQ6Z “100 Years of Amateur Aerials” The Radio Society of Great Britain is 100 years old this year. For the celebration they have gone through their archives and produced a set of talks. One talk is on 100 years of amateur aerials. Bill presented this talk with photos and discussion.
Upcoming Events
- June 8, 2014 - Manassas Hamfest Manassas, VA, Ole Virginia Hams http://www.manassashamfest.org/