I agree with Jim to watch out for the switcher power supplies. My own
experience with a Comcast unit replaced over the summer was noticed to be quite
ugly on 160m later in the fall when my focus turned back to TopBand. I could
easily trace the electrical wiring in our walls with my AM radio looking for
the source. Unplugged the very tiny wall wart and all was quiet. I plugged it
back in after the contest and found flipping it 180* was quiet, but as
originally plugged in was noisy. My outlet indicated proper wiring from one of
the usual plug-in checkers. I left it plugged in the "quiet" way.
tnx
Mike / W5JR
On Aug 26, 2013, at 3:23 PM, Jim Brown <jim@audiosystemsgroup.com> wrote:
> On 8/26/2013 11:33 AM, Tim Duffy wrote:
>> Also, how about RFI problems associated with nearby transmitting antennas
>> that might cause RFI overload problems to the Dish or Direct TV systems - as
>> in TVI?
>
> I would expect any issues to be the result of 1) noisy switching power
> supplies, 2) noise from the downlink electronics, and 3) common mode
> coupling on the coax (both TX and RX). and I would expect them to be easily
> solved by winding turns around ferrite cores. I had DirecTV in Chicago, and
> never had any issues, with antennas and DirecTV downlead in close proximity
> (5-25 ft). I don't remember if I did anything with chokes.
>
> 73, Jim K9YC
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