The Nashoba Valley Amateur Radio Club held its annual Homebrew / Show & Tell Night on December 18^th with numerous members displaying their different projects.  It was interesting to see what everybody was working on and here are three projects that really caught my eye.

Mike WU2D & Mark WA1QHQ displayed a number of different projects they had designed and built including a Noise canceller & a Paraset spy radio.  Mike explained his replica of a WWII Paraset spy radio and how it was used.  Originally built by the British it was used for clandestine radio communications in France.  The word Paraset is a combination of “radioset” & “parachute”.  Paraset radios were dropped by parachute behind enemy lines.  Mike & Mark have agreed to come back on March 19^th, 2026, to provide a more detailed presentation on spy radios, their history and how they work.

Phil W1PJE, brought in an old Western Electric automated tube tester from the 1960s.  While tube testers aren’t that unusual, automated ones from that time are.  Phil explained how punch cards were inserted into the instrument to configure the specific electrical parameters for each tube.  The automated tube tester was built into a rugged metal suitcase so it could presumably be tossed in the back of a truck.  Phil also displayed the companion library of old punch cards housed in a smaller rugged metal suitcase.

Tom W1PKX brought in his PKX40 transceiver that he designed and built.  Tom explained many of the features of this high performance 40w transceiver and some of his recent improvements.  I was blown away by some of the CW performance specifications of this transceiver and how they were similar to some top commercial radios.  For more information on this project and others that Tom has made you can look him up on QRZ.com.

Les, N1SV

The 48^th NEWS VHF/UHF/Microwave Conference was held in Windsor, CT from May 8^th thru 11^th.  This event brings together VHF/UHF/Microwave enthusiasts from around the Northeast and Canada.  They always have an interesting lineup of speakers.  This year there were two presentations that really caught my eye.

The presentation on Basic Light Communications by Paul W1VLF gave a good overview of the subject including an interesting story on how he scavenged 140 IR diodes for his optical transmitter from old tv remote controls when he worked for a CATV company.  Fred K1FMS followed this up with a presentation on the details of his equipment and a series of 940nm (319 THz) contacts he made with Paul at up to 25 miles so far using basic DIY hardware.

The optical equipment consists of simple available components that are mounted on a tripod.  A common transmitter consists of a bank of Infrared LED diodes combined to make a high-power emitter.  A cheap square wave generator powers the LED bank with a simple switch to send CW.  The receiver consists of an IR optical receiver IC behind a projection TV lense.  The output of the optical receiver feeds a trans-conductance amplifier and then a software defined receiver (SDR) like an AirSpy.

Following the presentations Paul W1VLF & Fred K1FMS displayed their equipment and gave a demo.  For more information visit Paul’s YouTube page https://www.youtube.com/user/W1VLF/videos .