On Thu, Jun 10, 2021 at 4:55 PM Greg D ko6th.greg@gmail.com wrote:

Interesting find, Bob. I have a copy of the 1948 ARRL Handbook, and they have a design for a "Self-Contained 60-Watt Transmitter for Three Bands" (pg 173). Uses a 6V6GT and an 807 (not 804). Covers 3.5, 7, and 14 megacycle bands (crystal controlled or with an external VFO; CW only). 5R4GY for the rectifier, 1.2kv center tapped transformer. Yikes!

Looks like quite a project. Speaking of 807s, I'm getting thirsty...

73,

Greg KO6TH

Robert Bruninga wrote:

...

I'm reading "the secret wireless war" and am surprised that the entire basis for transmitters throughout the British traffic network including spy radios and fixed stations transmission of decrypted ULTRA (Enigma) traffic to those with need-to-know was handled by a two tube 6V6 and 804 arrangement called the MKIII.

The secret service built them all themselves from the design in the ham radio handbook to avoid raising suspicions if they began buying the few commercial ham equipment.

That is the same arrangement as the first Novice transmitter I built back in 1963 in middle school just 18 years after the war. Amazing.

Bob, WB4APR.