On Mon,1/12/2015 12:56 PM, Kenneth G. Gordon wrote:
Ah, HA!!!! I have been hearing a very strong carrier, slightly modulated, on
14.030, and 21.063 for years and had never, ever thought it might be RF
from the network!!!!
If you have neighbors, it's quite normal to hear them too. When I lived
in Chicago, I heard at least three carriers most of the time. These are
locked to a clock in the router, each neighbor will be on a slightly
different frequency. To identify yours, kill power to the router/switch
and note which one goes away.
6 turns on a #31 or #43 2.3-in o.d. toroid is about right to choke those
carriers up to 10M, but you'll want 14 turns on a #31 to choke 160M and
80M, and it will still be effective on 40M.
Note that chokes can't help for interference that is coupled to internal
wiring of the router due to poor shielding or poor circuit layout, but
they will kill the common mode stuff coming in on the antennas (cables).
I've written extensively about this in k9yc.com/RFI-Ham.pdf. Lots of
conceptual discussion, lots of specific advice for different kinds of RFI.
73, Jim K9YC
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