[Heath] SB-200 weirdness

[pmarkavage at juno.com]

Years ago on one of my SB-200 I had similar problems. Jogging the meter
switch back and forth would clear the problem for awhile. Eventually
wound up replacing the meter switch. 

Pete, wa2cwa

On Sun, 23 Jan 2011 20:18:31 -0800 "Kenneth G. Gordon"
<kgordon2006 at frontier.com> writes:
> I am hoping that someone else here, besides me, has had the following 
> 
> problem with their SB-200 and can tell me what, if any, solution 
> they came 
> up with:
> 
> My SB-200 has had this problem since the day I bought it from a 
> friend: idle 
> current appears to be 10 mA instead of the correct 50 mA....most of 
> the time.
> 
> There will be times when the idle current suddenly appears to be 
> correct (50 
> mA), staying that way for, perhaps, a day, then dropping back down 
> to 10 
> mA.
> 
> During the times when the idle current is correct, input plate 
> current at 
> resonance, and power output rise to what I consider to be correct 
> values, 
> and grid current drops.
> 
> During those times when the idle current is low, I have difficulty 
> keeping grid 
> current below 100 mA (I prefer it to be about 50 mA), and both plate 
> current 
> and power output are low, plate current being lower than 400 mA at 
> those 
> times.
> 
> I have examined every component several times, subsituting a good 
> component where and when I thought I had a "marginal" one, but 
> nothing 
> seems to help.
> 
> I have also substituted final amp tubes, and the same thing occurs 
> with all of 
> those I have tried.
> 
> It seems to me that I am overlooking something, but I have, so far, 
> not 
> discovered what that might be.
> 
> Is there any help out there for this?
> 
> I am about to dismantle the entire thing and rebuild it from scratch 
> in hopes 
> that I will somehow find the intermittant part...if there is one.
> 
> Ken Gordon W7EKB
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