I am an amateur “ham” radio operator, call letters: N0DL, and have been active in that hobby since 1973, first licensed as WN0LSI then shortly after that as WB0LSI. Here’s a photo of the ham radio shack at the High School in Staples, MN from the early 1970’s:
Shown above: A Heath oil-filled ‘cantenna’, Drake W-4 directional wattmeter, Drake TR-4B and a Heath HD-1410 keyer that I’m pretty sure I built for the club from a kit (Heathkit).
I created a PowerPoint slide show on the
Reduction of Telephone Interference that I presented at the 1999 Dakota Division Convention here in Watertown, SD.
A fellow ham buddy and I used to own a repeater in the late 70’s. We had a local radio announcer with a nice voice create an audio ID for N0DL Repeater.
There weren’t too many repeaters with voice IDs back then so the repeater was frequently ‘kerchunked’.
Articles of interest to hams and audiophiles:
Balanced Lines in Audio Systems: Fact, Fiction and Transformers by Bill Whitlock (PDF, ~8Mb)
Because I can’t find it anywhere else on the ‘net, the OCR’d PDF of the 1994 EIA Source and Date Code Book listing transformer and capacitor manufacturers as of that year. Here is a plain scanned version if you find my OCR version doesn’t display properly. I also found and OCR-scanned the EIA 1995 Source and Date Code Book. Link to additional years of the EIA Source and Date Code book.
Good article on inductance of gapped ferrite cores: Evaluation of Factors Affecting Inductance Measurements of Ferrite Components by Barbara Ann Livermore and Jan M van der Poel.
Audio Tech Types: JVC Compulink files viewed using a soundcard.