[Amps] Henry 2KD-5 Problem

[Mitch Cox]

Grid to filament short in one tube.
  ----- Original Message ----- 
  From: TexasRF at aol.com 
  To: kb5gt at cableone.net ; amps at contesting.com 
  Sent: Thursday, May 26, 2011 6:38 PM
  Subject: Re: [Amps] Henry 2KD-5 Problem


  Hi Ed, sounds like a leakage to ground somewhere on the B+ side of the  
  plate supply. Perhaps a HV feed through lost it's insulation or plate bypass or 
   some other component in the B+ circuit has developed a leakage path to  
  chassis/ground.
   
  73,
  Gerald K5GW
   
   
   
   
  In a message dated 5/26/2011 5:18:23 P.M. Central Daylight Time,  
  kb5gt at cableone.net writes:

  Last  night I was using my 2KD-5, and it was working fine. After making
  several  transmissions with no problem, it made a loud pop when keyed. Now
  the grid  current indication goes off scale in the negative direction as 
  soon
  as it  is turned on, and stays there even with drive applied. It also has
  plate  current flowing ( about 300 mA ) even when not keyed. It is still
  working  and has output.
  I have to get someone to move it to my workbench due to a  back injury, so
  all I've done so far is to remove the top. The bias diode  reads 13.5 Kohm 
  in
  both directions when checked with one end of the 220 Ohm  parallel resistor
  lifted, but I see nothing that made the loud pop, so  far.
  When I get it on the bench I can get into it, but wondered if anyone  else
  had seen these problems in this or a similar amplifier.
  Thanks  & 73,
  Ed,   KB5GT
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