Topband: Common Mode Isolation

Bill Tippett btippett at
Wed Dec 28 13:37:20 EST 2005


 >In this system the antenna "pumps" the ground rod connection
up and down with voltage, since the ground rod is not a
perfect zero resistance ground. This effect is shared by the
coax shield, which if connected to the same ground rod would
also "pump" the ground voltage up and down the same way.

         Tom, most seem to recommend ferrites
on the outside of coax to reduce common mode.  Why
wouldn't a 1:1 isolation transformer with 2 turns
on both sides of a binocular core do the same thing?
Seems like this is how audio isolation transformers
work and I would think it should work for RF also.

                                 73,  Bill  W4ZV

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