a broadband high level modulator -1948

[Opcom]

"a broadband high level modulator"

Found this in an old magazine. September 1948 proceedings of the IRE. Interesting approach.
The IRE proceedings are online here but the issue is >18MB.
https://worldradiohistory.com/IRE_Proceedings.htm

The 5 pages are attached. If it's interesting then get the issue because its better quality.

[W7TFO]

Kinda reminds me of a Doherty-version of an audio amp.

73DG

[WBear2GCR]

Rather interesting.

Seems to have gotten lost in time.
Wonder if anyone ever built one.

It's a bit unclear how they derive the "rectified feedback"... but I'm guessing it's
a detector from the RF output?

The cost and size of an extra PS for the "boost" could be a factor, but I seem to
think that it ends up being two transformers, each of which works out to be
approximately 1/2 the current of the usual single transformer. But maybe only if
one assumed a duty cycle for a Class A PP modulator?? In AB only 1/2 of the tube
compliment is drawing current at a time... but in this scheme each power transformer
needs the same current available for each tube. Hmmm...

Then there are the issues of the choke...

Nice to get 100kc bandwidth!!! Ha!
Probably would pass a nice squarewave?

Interesting...

                 _-_-

[Opcom]

fig 4 on the feedback - they didn't connect a class C stage as a load for the experiment.