Topband: FairRite Products 2873000202

Gary K9GS GaryK9GS at
Sun Feb 5 12:15:46 EST 2006

Rick Karlquist wrote:
> 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.

Hi Rick,

That's interesting that Mini-Circuits used Parlyene.  It's a very 
expensive material to use although a great solution to the problem.  We 
have a Parlyene coating system at work and due to the way the material 
is deposited it costs the same amount of money to coat one as it does 
1,000 pieces.

Parlyene is a great material, tough and practically impervious to just 
about anything.  The nice thing is it is so thin it is almost impossible 
to even know it's there....something on the order of fractions of a 
thousandth of an inch thick.



   Gary Schwartz           email: k9gs at
   Check out K9NS on the web: 

   Society of Midwest Contesters (SMC)     GMDXA

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