[RFI] RF

Robert Nobis n7rjn at nobis.net
Fri Dec 23 16:41:55 EST 2016


Bill,

I had a similar problem with an electronically operated doggy door.  What I found was that I had relatively high common mode current on my antenna feed so the feed was also radiating. My antenna was not perfectly balanced as one end was close to metal siding. I added an antenna feed line choke following the recommendations from Jim Brown’s tutorial (k9yc.com/RFI-Ham.pdf <http://k9yc.com/RFI-Ham.pdf> ), and the doggy door problem disappeared.  I used 6 turns of RG8 through five 2.4” o.d. #31 toroidal cores for 80-meters.

73,

Bob Nobis 
n7rjn at nobis.net


> On Dec 23, 2016, at 10:59, Bill Price <billp7634 at sbcglobal.net> wrote:
> 
> 
> I live in a HOA subdivision with restrictive covenants. As such, at this time all my antennas are in my attic. I just strung a fan dipole up for 75 and 17. When I operate on 75 I have RF issues. Two of my security lights come on, one of the garage door opener lights come and an electric soap dispenser (motion activated) comes on and dispenses a butt load of soap. I thought it may be due to one side of the 75M dipole coming close to a length of romex. So I located that romex and put two snap on ferrites around that wire with the romex wrapping twice through the ferrite. I also put a ferrite on the power wire from the wall wart after having wrapped that several times. The problem still exists. I also have a 40M dipole and a 10M beam in the attic and have no problems with running a KW at any frequency other than 75M. The ferrites I have are a 31 mix. Any ideas as to how to solve this issue?
> 
> Bill   W5LO
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