[Amps] When does an GG Amp draw current.

[Jim Thomson]

Date: Tue, 31 May 2016 11:53:10 -0700
From: Paul Baldock <paul at paulbaldock.com>
To: <amps at contesting.com>
Subject: [Amps] When does an GG Amp draw current.

My 2 x 3-500Z amp starts to draw a few mA of grid current with about 
1 watt applied. Bias is about 8V.

My home brew GS35B amp  starts to draw a few mA of grid current with 
about 15 watts applied. Bias is about 40V.

Is my GS35B amp behaving as it should? When does an GG Amp start to 
draw grid current? Is it when the peak rf  voltage applied to the 
cathode exceeds the bias voltage?

Thanks

- Paul  KW7Y

##  U nailed it.   You require enough Rf V  to overcome the bias. 
Both amps are operating normal.   For CW use, you can increase the
bias V even more, a lot more, with the caveat that you dont lower the
idle current  down to 0-1 ma...other wise you will get key clicks.
10-25 ma of idle works just fine on any GG amp on  CW / FM...and is still AB2. 
Flip side is the drive requirement will increase. 

Jim   VE7RF