I have a few DirectTV boxes. Some old, some new.
havn't had too much noise from the boxes, but certain ham frequencies 160-20m
can make them unhappy with hi power I suspect the heads (lna) in the dish arm
just got overloaded . within say 30ft antenna to antenna. thats with a
text book install and set up good swr , resonant antenna, good grounds etc
havent' given any rfi to the set top boxes
goodluck
N2EHG
"No matter where you go there you are". Buckaroo Bonzi across the 8th
Dimension...
On Aug 26, 2013, at 3:43 PM, "W5JR.Mike" <w5jr.mike@gmail.com> wrote:
> 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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