[Amps] Heathkit Warrior High Plate Current

[Paul Kraemer]

Eddie
I seriously doubt there is anything wrong with power supply choke from what 
you describe.
Sound like instability in amplifier plate circuit from any number of 
possibilities, open connections, defective t/r relay to ???
Paul K0UYA
----- Original Message ----- 
From: "Eddie Bradshaw KJ4R" <kj4r at ftc-i.net>
To: <amps at contesting.com>
Sent: Sunday, October 19, 2008 8:10 PM
Subject: [Amps] Heathkit Warrior High Plate Current


>I recently bought an "as is" Heathkit HA - 10 Warrior.  The amp is in good 
>overall condition, but I'm having a problem that has me stumped. Here is a 
>little background........ The amp has relays installed for transmit / 
>receive switching and standby bias switching.  The standby bias is 
>around -75v and the bias during transmit is -7v.  The plate current is 
>around 30 ma with the cutoff bias applied which is normal.  When the amp is 
>switched to transmit, the plate current rises to 100ma, which is also 
>normal. I've experimented with adjusting the transmit bias to the 
>recommended -4.5v but it has no effect on the problem.
>
> The problem arises when I apply even the slightest level of drive to the 
> amp.  The least amount of drive causes the plate current to rise to almost 
> 500ma or higher with very little output power. The tune and load controls 
> seem to have no effect on the plate current.  I've tried the amp on all 5 
> bands and the problem is the same on each band.  I'm driving the amp with 
> a Kenwood TS 530 (tube output). I suspect the swinging choke may be bad, 
> but I'm not sure how to test or verify it.   Any ideas from anyone who has 
> experience with this amp would be much appreciated.   Eddie KJ4R
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