Jim Land (NO SPAM) wrote:
(---Pete---) wrote in news:448eb552.31404968
@news.verizon.net:

Hi all,
I have a background as an electronic technician and this issue
has me puzzled. My neighbor lives in a house about 25 feet from
my home. He plays his stereo so loud with RAP music that the
windows on his home rattle. The bass comes thumping into my
home at a level of -4db on a sound level meter range of 70db.
That's just to give you a general idea how loud he plays it.

Here's the part that puzzles me..
When he really cranks it up I'm getting interference on my TV
on Ch2 only. It looks 2 or 3 wide white horizontal bars that pulse
with the bass.

I have an antenna on my roof and no cable TV. How can an audo
system interfere with a TV signal when the frequency ranges are
so far apart?

First figure out where the interference is entering your tv. If you
short out the antenna terminals, does it go away?

If not, try putting a line-filter between the wall receptacle and your
TV's power cord.

If so, it's entering either at the antenna or the downlead. You might
consider moving the antenna to the area of your roof that's farthest from
the neighbor, and/or changing from twin-lead to shielded downlead from
your antenna.

The whole field of radio-frequency interference (RFI) of TVs is an
interesting one and books have been written about it. See, for example,
The ARRL RFI Book, http://www.arrl.org/catalog/6834/
It's for radio amateurs, but the underlying principles apply to your
case, and are completely understandable by a technician like yourself.
(For example, your neighbor might be radiating at a much lower frequency
than channel 2, but with a harmonic which is close to channel 2; this can
be cured by putting a low-frequency filter on your tv's antenna input.)


I think building a high-power transmitter and aiming it at your
neighbor's stereo in the hope of overloading the input stages of the
amplifier is the best thing to do, even if it is illegal. If the streo
dies every time he turns the volume up, he just might figure out to
keep the volume lower. OTOH, some people just don't get it no matter
what - hence the Darwin Awards.

H. R.,(Bob) Hofmann