On Wed, 9 Nov 2016 15:25:58 -0500, "Michael A. Terrell"
wrote:

Jon Elson wrote:
wrote:

I tried posting something about this in the past but got no response. I'm
holing that this time someone might read it who may have a theory as to
what could be going on.

I live in southern New Hampshire and watch OTA TV out of Boston, which is
about 60 miles from here. Lately I as well as several other people I know
have been experiencing intermittent problems with channel four. While most
other channels are presently operating fine, for the past 10 days or so
channel 4's signal has been in the toilet. This station, WBZ TV operates
on UHF channel 30, runs 825KW, and has an antenna height of 390 meters. By
contrast Channel 5, WCVB, operates on UHF channel 20, runs 625 KW, and
shares the same tower and has it's antenna at the same height as channel
4's, and we never have any problems with that channel. Could propagation
be that much different 60 MHZ apart? What is really weird is that the
signal just drops to almost nothing.

I discussed this with the chief engineer at Channel four and he had no
explanation for this. Does anyone have any theories about this? Thanks,
Lenny
Anybody hit or knock down a pole in the area? I assume your neighborhood is
wired for cable. Damage to poles can knock connectors partially loose,
allowing a LOT of signal to flow onto the outer sheath. Could be a signal
right on the same frequency as Chan 4.


Digital CATV uses QAM modulation, not ATSC.

What is your point? His point was that a leaky cable system with
signals on channel 4 could interfere with the OP's over the air
channel 4 signal. That is certainly possible even if different
modulation schemes are used. (And by channel 4, we mean virtual 4 -
RF 30).