On Tue, 11 Oct 2011, Scott Dorsey wrote:

Clutter wrote:

Great info. I had heard these were supposed to be fairly easy to fix
with that sort of problem. Your very specific suggestions are enough
to motivate me to take a second look at my beloved old boatanchor.
So I will as soon as I can get to it, and I'll stop back here and
let you know how it went.

The good news is that, unlike cheap Heathkits, they don't blow up their
power transformers often at all. Everything except the CRT and the power
transformer is readily replaced.

I have a 545?, the one with plugins that was first sold about 1959,
someone found it as a hospital discard and gave it to me.

This was 20 years ago. After a bit of use, I notice the trace is not
straight, clearly a bad filter capacitor in the power supply. I actually
find it by using the scope to check itself, at one point the trace gets
even more non-straight, so that was the bad capacitor. It was a fairly
large value for a high voltage electrolytic, I expected problems. But
there at the local surplus store was the right capacitance and voltage.
And then the trace was back to normal.

Michael VE2BVW

On 10/11/2011 02:12 PM, Michael Black wrote:
On Tue, 11 Oct 2011, Scott Dorsey wrote:

Clutter wrote:

Great info. I had heard these were supposed to be fairly easy to fix
with that sort of problem. Your very specific suggestions are enough
to motivate me to take a second look at my beloved old boatanchor.
So I will as soon as I can get to it, and I'll stop back here and
let you know how it went.

The good news is that, unlike cheap Heathkits, they don't blow up their
power transformers often at all. Everything except the CRT and the power
transformer is readily replaced.

I have a 545?, the one with plugins that was first sold about 1959,
someone found it as a hospital discard and gave it to me.

This was 20 years ago. After a bit of use, I notice the trace is not
straight, clearly a bad filter capacitor in the power supply. I actually
find it by using the scope to check itself, at one point the trace gets
even more non-straight, so that was the bad capacitor. It was a fairly
large value for a high voltage electrolytic, I expected problems. But
there at the local surplus store was the right capacitance and voltage.
And then the trace was back to normal.

Michael VE2BVW

So, clearly this is a boatanchor I should keep
(546 and three plugins *and* cart)!

73, David K3KY