[Amps] Alpha 8100/GU74B Tetrode question

[Gary K9GS]

Hello all,

I have an Alpha 8100 with a pair of GU74B/4CX-800 Tetrodes.  I recently 
had a problem occur with the amp going into a fault condition as soon as 
any drive was applied.

Through some help from RF Concepts, I isolated the problem to an open 
series resistor that supplies screen voltage to the tubes.  It's a 15 
ohm/1 W resistor.

My question.....what would be the most likely cause for this resistor to 
fail open?


-- 


73,

Gary K9GS

Greater Milwaukee DX Association: http://www.gmdxa.org
Society of Midwest Contesters: http://www.w9smc.com
CW Ops #1032   http://www.cwops.org

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