[Elecraft] Broken core

Stuart Rohre rohre at arlut.utexas.edu
Wed Mar 15 20:24:12 EST 2006


Super Glue should be fine.  Some epoxies however, have fillers in them and 
might NOT be passive to the RF specs of the core.

I saw this happen while working in the EMC field.  We were testing a 
transformer for a customer that had to attenuate RF passage thru its core 
and windings.  It was a three phase power unit for a LORAN station.

They potted each phase core in a chassis with epoxy and sand mix. 
Unfortunately, there were some ferrous rocks in the mix and, the RF 
attenuation was affected such that the transformer FAILED the RF attenuation 
test.  It passed LORAN signals like a tuned circuit!

Made me realize that colorant in an epoxy might mean there are things other 
than adhesive in the mix.

Stuart
K5KVH 





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