[JMS] Is anyone running a 90881 amp?

Sat, 6 Mar 2004 02:59:37 GMT

Thanks Jim/co on the advise:

FYI, I am not running the 90881 in plate modulation configuration. It will be per the manual: that is cathode modulation. I suspect I can jack up the bias on this for class C operation. Won't this require more drive from the 90800 transmitter? Also, how will this situation be affected by cathode modulation? Thanks. Cal, N6KYR. 

Cal,

You can run a push-pull amp in Class C just as well and as easily as you can run 
it in Class B or Class A.  Just set the bias and plate voltage according to the 
handbook recommendations.  By the way, we had a home brew push-pull 812 final on 
the air at W8GYH, my High School radio club, back in the 50's.  We drove it with 
a 90800, ran it class C, and modulated it with a pair of 211's (push-pull, class 
B).  So I do have some experience with an amplifier that was awfully close to 
your 90881.  

Jim, W8KGI

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