[Heathkit] SB-610 focus problem?

[Ian Wilson]

Some of the Heathkit scopes have a separate Astigmatism trimpot
in the HV divider chain. The SB-610 doesn't. I would guess that some
CRTs are OK without and some need the extra balancing.

The deflection circuits are single-ended so there's always going to
be some compromise, I think.

73, ian K3IMW



On Sun, Oct 27, 2013 at 6:54 PM, Alexander N. Gerli <ac1wye at gmail.com>wrote:

> *Hi, folks,
>
> *
> *I've been using my '610 for a long time and it's always been reliable,
> especially after I recapped it.
>
> *
> *I'm wondering about something. For those who run these, have you ever
> noticed how the trace line can be focused real sharp in the center and it
> gets out of focus at the edges? Not by a whole lot, but it's noticeable.
>
> *
> *I also have a HO-10 I've rebuilt and I use that on my bench with my dummy
> load for testing. The horizontal trace on that is clean all the way across
> once the focus is set.
>
> *
> *Is there something I need to get into and check on the '610, maybe an
> out-of-spec resistor(s) or something else in the Focus circuit? Anybody
> have a thought on this?
>
> *
> Thanks es 73,   Sandy AC1Y
>
>
> Alexander N. Gerli, Sr.
> 548 Allred Mill Road
> Mount Airy, NC 27030-2202
>
> Scotsmen walk about 900 miles each year.
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