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Old September 3rd 07, 04:47 AM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default making a common mode filter

On 03 Sep 2007 03:26:50 GMT, Ed G
wrote:

loop fed by an SG-237 tuner. I wanted the choke for the coax feeding the
tuner.


Hi Ed,

You will have to choke the control lines just as much.

I do have RF causing
various issues inside the coach while I am transmitting.


That could be as easily through the air, or "ground currents" in the
chassis. All points of the chassis, doors, hood, etc. are not usually
bonded very well. Even the exhaust system can be "floating" to
provide a path from ground, right up into the engine compartment.

On your RV grounding question, yes, the antenna feedpoint and all
related ground areas are very well bonded to the main vehicle chassis
with rather large tinned braid, (2" wide).


Re my paragraph above, does this include doors? A lot may be taken
for granted and hinged points are sometimes insulated, allowing large
panels (capacitive plates) to couple RF inside what is considered to
be an otherwise tight box.

73's
Richard Clark, KB7QHC