[Milsurplus] [ARC5] GO-9: Cathode Mod Questions

[Kenneth G. Gordon]

The October issue of Electric Radio Mag includes an excellent article on 
cathode-modulation beginning on page 34.

I highly recommend it to anyone contemplating this method. From this article, it appears that 
rather than dropping the final plate current by 50%, it is better to drop it even further before 
modulation....like 70% lower, or 30 watts instead of 100 watts.

I also have a long discussion of that method in an old Radio Handbook around here  
somewhere. 

And on this page:

http://www.w7ekb.com/glowbugs/projects/index.html

you will find a discussion of a cathode-modulator used with a transmitter which uses a 
250TH final amp by Dennis Brady W5FRS and Patrick Jankowiak.

Many years ago, I built one of those cathode-modulators which had been published in either 
QST or the handbook, and used it with my DX-35, mainly just to experiment with it, since the 
DX-35 already included controlled-carrier modulation. My mic was a JT-30 crystal mic.

Testing audio quality with local hams showed un-important differences, and both sounded 
pretty good. One fellow ham recorded my audio and played it back to me, and I was 
pleased.

But, of course, I was young and didn't know anything either.

Ken W7EKB