[Hallicrafters] SX28 power transformer

[Roy Morgan]

At 09:27 AM 7/29/2005, Todd, KA1KAQ wrote:

>Roy and I disagree a bit on a few things here.

Todd,

Well, not necessarily.

>  Roy thinks variacs are evil and shouldn't be used because you will kill 
> your radio eventually if you use one.

Not "will" but "can". And it all depends on how you use the variac.

>... I also disagree that you can't 'bring a
>radio up slowly' with one because you can - it's just a lot more
>involved than plugging it in and cranking the knob every few hours.

I completely agree on this point.  My whole point is to get bad capacitors 
out of there before you put normal power to the radio.  (And get the 
dampness out of high voltage windings.)

>...Simply sticking a 60w bulb near the transformer in a cardboard box for a
>limited time is more likely to give you a false sense of security than
>it is to really drive moisture out of a transformer.

This could very well be true. Maybe an initial resistance measurement 
between windings on the transformer would help you track how much moisture 
has been heated out of the thing.

> > >... Check your voltages, change the necessary components
> >
> > No. Replace the caps first.
>
>This is another area where I disagree(with one caveat*) with Roy,
>simply because the 'shotgun' approach can and often does) create more
>problems than it solves.

I was too terse: Replace the BAD caps first, and/or the ones most likely to 
cause damage (like audio output tube grid coupling caps.)

>  Wholesale replacement of components can
>create problems

I agree. I don't recommend wholesale replacements of components (unless 
they are the failure-assured paper foil caps we hear so much about.)

Roy


- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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