CBM8032 - wobbly screen (The saga continues)

From: Adrian Vickers <avickers_at_solutionengineers.com>
Date: Sat Oct 6 20:14:30 2001

Hi Michael, welcome to the list! I hope it proves as useful to you as it
has to me (so far) - I only hope I can be as useful myself someday...

At 23:15 06/10/2001, you wrote:

>Tha most probable cause is indeed the transformer, more precisely: the
>aging core
>of the transformer. This core usually is made of a lot of thin sheets of

[snip excellent description - and yes, eddies is correct]

>Now, this is the point: With old transformers, this insulation starts to
>literally crumble
>away, which leads to a significantly larger stray magnetic field around
>the transformer.

I can see how this could be the case. for instance, I can't believe that
Commodore would have let the units out of the door 20 years ago with as
much screen wobble as is present in mine. In fact - I know they didn't, as
about 10 years ago I used an 8032-SK for quite some time, and that
definitely didn't wobble.

>Shielding of the old transformer is no real option. You would need what
>we Germans
>call "mu-Metal", which is a special alloy of steel and other things i
>have long
>forgotten but that make it EXPENSIVE.
>It is magnetic, but not a good conductor, which make it ideal for
>shielding magnetic

Oh, I don't know. I can probably get hold of some for relatively little
money (beer tokens, if that).

>You could try a shielding out of steel sheets, but they might get hot if
>the stray
>currents induced by the transformers magnetic field are too large. And
>the shielding
>effect is not too good...

I may give something like that a whirl, just to check it is the problem.
I'll also be having a poke around to make sure it's not being unnecessarily
amplified by a component failure. And the caps are still on the list... :)
When I've finished this one, I've got two more to do.... AND there's
another 8032 to breath life back into (that one is more seriously broken).

I can see I'm not going to have much time left over to do my motor
racing.... :)

>I live somewhere in southern Germany, which is not that bad. No,
>really.... 8-)

Well, it's got to be warmer and drier than the UK....

Cheers, Ade.
Be where it's at, B-Racing!
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Received on Sat Oct 06 2001 - 20:14:30 BST

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