[Heathkit] Heathkit SB-610 monitor scope

[Donald Spoon]

This is just a Wild Guess, but you might want to check into the circuits 
of the SB-614 and SB-620.  I was needing a new power transformer for my 
SB-614 and found out the same one was used in the SB-620.  The P/S 
supply circuits were identical!  Those circuits "might" give you some 
ideas of how to replace the rectifiers, and "might" be quite similar to 
yours...  dunno since I don't have the SB-610 schematic here.

Wouldn't hurt to replace the filter caps with higher voltage ones...  
They tend to go out in the SB-614, and are the first place to look when 
you lose HV.

Just some thoughts...

Cheers,
-Don Spoon-

On 11/7/2011 7:25 AM, Dick KF4NS wrote:
> Decided to dig into it again since I had not done much with it since I got it 2002 and replaced all the
> power supply caps. Recent testing showed poor focus and low vertical gain.
>
> I found the two B+ diodes shorted. Wow, never saw any selenium rectifiers that looked like those two. The
> focus problem should be fixed after replacing the rectifiers and a few resistors. About those diodes, I
> will likely use a couple 1N5408s but the usual thing would be to series a resistor with each anode lead
> which is usually a good idea in power supplies with original seleniums. In this case though I wanted to
> get you input because I noticed that the capacitors are not electrolytic and there shouldn't be the usual
> increase in voltage. What do you think? One chap has a solution online whereby he used 4 1N4007s in
> series for each replaced diode which I guess he thinks will make up for not using series resistors.
>
> I also observed that the blue and yellow xfmr leads are reversed but don't believe that should be a
> problem since we are looking at AC here and don't think secondary polarity should be of concern here.
>
> I have a couple options here will take care of the vertical gain situation. Got that covered.
>
> 73, Dick KF4NS
> St Petersburg, FL 33714 USA
> Keep The Glow!
>
>
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