[SCCC] SB-220 Re-Build

[Joe]

I have been re-building this AMP.
Installed:
Harbach Soft Start,
Harbach RM-220 Meter Board,
Toroid HV Transformer,
New HV Filter cap's stack and resistors,

Now that the HV Transformer is close to 1 KV higher than Stock, The 
diode string on the Harbach board did not supply a high enough Bias 
voltage. Idle current was close to 250 ma. Thats almost 900 Watts of 
power doing nothing really. And the tubes would turn orange just idleing 
doing nothing amplifier wise.

So I added some more diodes to the string to get the Bias down to a more 
reasonable level.

The AMP works great BUT.....

Before it let all it's smoke escape (the reason for the rebuild) it had 
some sort of a Homebrew Bias circuit that shut off the Bias when the amp 
was not needing it. the AMP ran MUCH MUCH Cooler!

But this Bias circuit must have had it's smoke escape also because it no 
longer works.

So been hunting for a design of another one, and have actually found a 
ready to install one. from Ameritron.

http://www.ameritron.com/Product.php?productid=EBS-1H

They will sell me one, but will not provide any support because it will 
not be going into an Ameritron AMP.

They provide a downloadable schematic,,,, well kind of. it is of such 
poor quality Very low contrast, and the resolution is soo bad, by the 
time you enlarge a connection lead to learn what it is, the name of the 
lead is un-readable.

So I am looking for anyone that has used one of these in a SB-220 with 
the Harbach Meter board.

Joe WB9SBD