[Heath] SB-200 problems...solved...

[Kenneth G. Gordon]

On 20 Sep 2011 at 15:14, Jerry Haigwood wrote:

> Ken,
>     I get about 90 mA of idle current using the Keyall.  I don't think it is
> affecting my SB-200.

It sure doesn't sound like it, all right. Out of my curiousity, which 572Bs are you using? 

>  I also added a soft-start circuit, HV fuse, glitch
> resistor, new fan, new caps, new rectifiers, meter protection diodes, new
> tubes, new knobs and a new paint job.  I get 600 Watts output with 52 watts
> of drive.  It is a very nice amp.

Well, I certainly agree with your assessment. IMHO it IS a very fine amp. Completely reliable 
and always works. I get a minimum of 600 watts output with between 50 and 70 watts of 
drive, and as soon as I "indulge" in some of the suggested mods at this site:
 
http://pa0fri.home.xs4all.nl/Lineairs/SB200/sb200eng.htm

I expect it to be even more reliable and efficient.

I had already installed new caps and new diodes, and done some work in the final "cage" to 
improve efficiency.

It is pretty obvious to me that most of the problems I have been having with this particular 
SB-200 are due to poor original construction and abuse by later owners. I bought it used from 
a ham north of us, who had bought it used from someone, who had...etc.

vy 73,

Ken W7EKB
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