[AMPS] vom check of 3-500Z tubes

[Ron D. Rossi]

Jim Spears" said: 
> 
> >
> >> my amp supply lk-500 zb did a funny thing a while back when I powered
> >> it up after a long time in the closet and a cross country move.  so
> >> far I have found a blown 1 ohm, 5 watt wire wound resistor.  it was in
> >> two pieces so there is little debate on whether or not it blew...

I am one of the least experienced amplifier debuggers on the reflector having 
only debugged and repaired five HF amplifiers (some more than once due to 
severe contest quest-op abuse). I have spent a great deal of time however 
troubleshooting other electronic things in my career.

I try to start with an open mind to the problem. Root cause determination is a 
methodical process. Analyze the failure and then take the simplest and least 
expensive steps first working toward the more expensive and exotic. In this 
case DC check the tubes, look for obvious arcing or a discharge path, inspect 
and measure critical components in the path. Then replace the resistor and try 
again! Dust, bugs, errant shards of solder, etc. could surely trigger the 
disappearing glitch resistor trick. Doesn't it make sense after following the 
steps above to just replace the resistor and fire the rig up again? Then take 
the next step.

I stand ready to be corrected!

-- 
73 es God Bless de KK1L...ron (kk1l@arrl.net) <><
QTH: Jericho, Vermont
My page: http://www.qsl.net/kk1l



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