I have a garage that is fed with a 3 wire feed from one pole transformer and
my house is same from a different pole transformer. Both locations have a
ground rod attached to the box. The cable TV is connected to both sites
using a splitter. ( This was installed by the cable company before I bought
the house) Is this a possible ground problem? The cable eventually connects
the shield to the ground of each television in both locations. Saw a similar
post the other day that got me thinking.....
Anything can happen with ground/hum, but methinks the solution is
dirt-simple, if there is a problem:
Connect both ground rods with a wire.
Proly not a bad idea even if there isn't a problem, if one ground is
superior to the other, which can easily be the case. Codes notwithstanding,
You probably have a ground loop. Do you have a hum problem at any of
the tv locations? If not then I would not worry about it. If you do
then the correct solution is to get an isolator for one location. The
quick and dirty solution is to lift the ground at one location.
Ground loops often have a small differential voltage typically present
as 60 cycles. It's not dangerous but often gets into audio circuitry
which is designed to amplify anything between 20hz and 20khz.
Adding more ground connections seldom helps as they all must travel
some distance and that's the reason you have a problem.
EA has the right answer, bond the ground electrode systems together.
When I was in the computer business we fixed a lot of problems this
way when networks spanned several buildings. A lightning strike will
resolve this ground shift through your TV if you don't.
Like was posted, if you have a hum you probably have a ground loop, if
not hum, don't worry about it. I worked on a friends entertainment
center for hours before finding that if, and only if the center bass
speaker for surround sound and the cable tv was hooked up, he would get
a real bad hum. I forget how I fixed it?
Stuff happens and this arrangement may makes stuff somewhat more
likely to happen.
A house may last your lifetime and never need the ground connection
that was provided for it. What happens if one day that ground is
called upon to do its duty and the only path it has is through your TV
set, cable box cable modem and various other equipment out in the
garage. For audio there are isolation transformers commercially
available made to handle the situation you describe. I dont know if
there is anything available to isolate a cable TV signal
commercially.Perhaps googling TV isolation transformer may return
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