Re: 547 HV Transformer: Bill Schell rewind failed
Chuck Harris <cfharris@...>
Hi Tom,toggle quoted messageShow quoted text
Moisture is definitely a factor, but the problem is not
Yes, you can gain an improvement by cooking, or vacuum
drying, a tektronix epoxy transformer, but it will return
to its failed condition in a much shorter time than it did
My guess is the brownish/red coloration to the epoxy is
because tektronix added a fire retardant to the epoxy...
most everyone did back then, resulting in a lot of failures
over the years. One place you hear quite a lot about it is
in red doorknob style epoxy molded HV capacitors.
Time has showed that the bromine, and other fire retardants,
have failed in a variety of ways everywhere industry used
Fire retardant plywood loses its structural integrity after
about 10 years, causing roofs to collapse. Fire retardant
added to plastic computer and monitor enclosures caused
them to turn brown over time... and let's not forget about
tris added to kid's pajamas!