Topband: FairRite Products 2873000202

[Rick Karlquist]

Minicircuits coats their cores with "Parylene".  The cores are conductive
like FairRite73 and are in fact probably similar material.  A long time
ago, a batch of uncoated cores managed to find their way into a bunch
of ASK-1 mixers.  We had a special application at HP where we put a DC
bias on one of the windings.  Most users do NOT do this.   These
defective mixers caused a devil of a problem because they didn't
just fail outright.  They would get noisy when DC was applied
and eventually short out the DC.  It took us 6 months to get MCL
to admit the problem.

What I learned from this is that you should not wind ordinary
enameled wire on conductive cores even if it seems to be OK
at first.  It may be a time bomb.

Rick N6RK