WORKSHOP AND MINI-SWAP MEET REPORT
Sunday February 16, 2014
Pavek Museum of Broadcasting
St. Louis Park, Minnesota
It was another very cold day, but a small group of dedicated radio collectors still set up tables and sold a few radios prior to the workshop. But mostly they were all waiting for Steve Raymer to open the door, so they could go inside and warm up.
Everyone piled into the warehouse to see what was for sale, and we found a nice variety of items marked with reasonable prices. There were several horn speakers, some vintage tube hi-fi, and a number of floor model radios. Probably the best deal was a heavy 1930 Fada console in a fancy cabinet with carved sides for $35. Kip Wallace brought snacks and soft drinks and we had about an hour to socialize before the workshop started.
As usual, there was a good sized crowd. Steve Raymer ran the show and started by having Jim Thompson tell us a little about the upcoming Radio Daze 2014 event. It should be another must-attend meet!
Next, George Werl demonstrated a freeware SPICE program, LTspice IV, a very powerful tool that can be used to design electronic circuits and simulate their operation on a PC. George also presented a brief history of how Tesla was able to broadcast power, and then entertained us by operating his Chromatic Electricity Demonstrator, which he claimed was like one Tesla had, although it seemed to most of us that there might be some sort of trick involved. See him demonstrate this to some kids at the Pavek Museum: Vimeo video
Steve Brown, a CBS Radio Engineer who works with the antenna towers in Shoreview, demonstrated how an Array Solutions model 4170 Antenna/Lab RF Analyzer can analyze transmitting antenna circuits. It is simply a circuit board that plugs into a PC, along with some software, and costs about $500. It can be used to measure antenna SWR curves by sending pulses over a range of frequencies and monitoring what is reflected back.
Ken Ladd talked about various crystal radios he has built, many with parts scavenged from household items. Jim Reynolds had a inexpensive portable shortwave radio from the C. Crane Company capable of presetting 200 stations. Sanyo Eneloop rechargeable batteries were recommended.
Steve Raymer talked about Del Schlumpberger's method to replace a 6U5 magic eye tube with an easier-to-find 1629, and Lyn Mattson told us about a transmitter project he is working on.
Steve wrapped up another great workshop with a demonstration of Allen Lein's latest handcrafted vacuum tube Dual Curve Tracer. Thank you Steve!