Jim-
Was the update to the 168 page power point entitled "Coaxial Transmitting
Chokes"
Or to:
"A Ham's Guide...."
Version 5a, 5 June 2010
Or:
Something else?
Thanks,
73
Ed McCann
AG6CX
Sent from my iPhone
> On Dec 23, 2016, at 2:33 PM, Jim Brown <jim@audiosystemsgroup.com> wrote:
>
> 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
>>> _______________________________________________
>>> RFI mailing list
>>> RFI@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/rfi
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>
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