[Heathkit] SB-610 focus issues

[manualman at juno.com]

Chuck:
Count yourself lucky you have one SB-610 that doesn't have an astigmatism
problem with the trace. Even though you have checked all related
components, I would checked them all again especially the resistors. Some
resistors will change value when current is flowing through them. If
they're the original resistors, I would replace them. Also consider
adding an astigmatism control similar to what's in the SB-620 or SB-614.
If I remember correctly, both of my SB-610's, HO-10, and HO-13 all now
have an astigmatism control.

Pete, wa2cwa

On Sun, 28 Sep 2014 15:50:39 -0700 Chuck Penson <wa7zze at gmail.com>
writes:
> Thanks, Glen. The 610 in my main station does not exhibit this focus 
> problem. It is sharp from end to end. The 610 on my bench is another 
> story.  I have not seen this trouble on several IO-21s that have 
> passed through my shack. They were all sharp. 
> 
> Curious. 
> 
> Chuck / WA7ZZE
> 
> > On Sep 28, 2014, at 3:33 PM, Glen Zook <gzook at yahoo.com> wrote:
> > 
> > Very common with the SB-610!
> > 
> > One can get a "so so" focus across the entire line.  But, 
> definitely not sharp.
> >  
> > Glen, K9STH 
> > 
> > Website: http://k9sth.net
> > 
> > 
> > On Sunday, September 28, 2014 5:10 PM, Chuck Penson 
> <wa7zze at gmail.com> wrote:
> > 
> > 
> > Hi, all;
> > 
> > I've got an SB-610 that works great but the trace goes out of 
> focus at the far ends. So, good in the middle and not so good at 
> either end. One end or the other can be brought into focus but then 
> the middle goes out of focus. 
> > 
> > Have checked all the focus related voltages and components. 
> > 
> > Any ideas?
> > 
> > Thanks!
> > 
> > Chuck / WA7ZZE