Results tagged “circuits”

Radio 1946

Radio - Design, Production Operation, a technical magazine from 1946

I've always liked collecting old radio books and magazines, from kid's science project books to Popular Electronics.


I enjoy reading the scans done by other radio freaks trying to preserve history, so here's a contribution from me, scanned several years ago. It's a trade magazine called Radio, with 56 pages, written for engineers and technical people. One could say it's like a 1940s version of Radio World.

I believe that this magazine came from the trash of Peter Granba here in Pittsburgh. In the 1980s there was a big curb side trash pile on a main road nearby, and the trove was so good that I asked my dad to drive me there so that I could pick up some of the radio-related items. Granba was apparently a Ham radio operator and electronics experimenter.

April 1946 contents include:

  • Cover: Western Electric's 'Clover-Leaf' FM broadcasting antenna
  • Inductive Tuned Loop Circuits
  • IF Amplifier Stability Factors
  • Electro-Mechanical Analogy In Acoustic Design
  • AM Transmitter Design
  • D-F For Static Pulses
  • Recent Radio Inventions
  • Bridged T And H Attenuators, Diode Conduction
  • Loss Due To Shunt Or Series Resistance
  • Capacitor Machine, Co-ax And TV, FM With Non-Linear L

In 1946, television and FM seemed to be well on their way, with the FM antenna tower on the cover, and high power FM, VHF, UHF and microwave tubes for airplane instrument landing being detailed. One advertisement is for the Eimac 3X2500A3 external anode tube, capable of 3500 watts output from 88-108 mhz, the modern FM band.

My favorite article is Modern AM Transmitter Design starting on page 30, which is about the latest 250 watt broadcast transmitter, as used in many communities across the country. It's fan-less, so it can be placed right in the studio, uses motorized final amplifier tuning, a high level plate modulator, and has a frequency response from 30 to 10,000 hertz.

250 watt AM band transmitter

Get the full draft quality but readable PDF scan here: