[R-390] Z503 Replacement

[rbethman]

I've torn one coil that was an excess part, since it had been damaged 
elsewhere.

I have no idea what the resin was, but it showed no flexing remnants.

I have gone as far as chipping off the ferrite cup, AND *still* have 
continuity.

I believe that Roger has it correct.  It would very likely be a flaw in 
the wire itself.

Having wound transformers, it is NOT the easiest thing to do.  You MUST 
remain vigilant and watch closely for some unusual twist or flaw in the 
wire as you go along.

Bob - N0DGN

On 4/4/2011 9:13 AM, bavarianradio at comcast.net wrote:
> I have been kicking this question around as well. In several discussions with other techy types, we are surmizing that the varnish/laquor or whatever it is that it's potted in, becomes quite brittle and is actually breaking the wire where it passes through the material.This could be very likely enhanced by temperature change or temperature extremes like un heated/cooled storage.It would be interesting to carefully disassemble one that is open and try to find the break. FWIW mine is still working OK  after the arc repair I performed on it almost 2 months ago. I don't expect it to last forever though. Ross W1EKG
> ----- "Stephen M. Murphy"<murphys at comcast.net>  wrote:
>
> That's what I was wondering, whether it is a manufacturing defect or an
> upstream failure causing the problem, since these things typically don't
> (can't) just fail on their own.  I'm also wondering if it's an "across
> the board" problem, or just affects those radios that were subjected to
> outdoor storage.
> 73-
> Steve
>
>
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|               AM Amateur Radio Operator    NØDGN                 |
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| Bob Bethman                \\\|///     " The absence of a danger |
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