Bill and Bob,
While this is certainly worth trying, I suspect that the problem is
caused by the antenna itself being so close to the victim devices. And I
would definitely wind serious chokes onto wiring connected to that
garage door unit. By serious, I mean at least 12 turns around a #31
toroid, or half as many through a clamp-on that's an inch long.
Since this antenna is inside, I suspect that you're running barefoot. If
so, or if you're running less than about 300W, the bifilar-wound choke
using a pair of #12 or #14 THHN on a single #31 core would handle the
power unless the antenna is VERY badly unbalanced.
BTW -- about six months ago, I updated RFI-Ham.pdf to address power
handling of bifilar wound chokes on #31 toroids. If you are considering
using one, by all means download it again.
73, Jim K9YC
73, Jim K9YC
On Fri,12/23/2016 1:41 PM, Robert Nobis wrote:
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@nobis.net
On Dec 23, 2016, at 10:59, Bill Price <billp7634@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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