[dizzy]

I switched from satellite to cable, and that cable going into the back
of the TV has introduced a terrible hum into my stereo/surround
system. I have to pull the cable from the TV when I want to listen to
music!

Anyone have experience with a good solution?

[whosbest54[_2_]]

In article ,
lid says...



I switched from satellite to cable, and that cable going into the back
of the TV has introduced a terrible hum into my stereo/surround
system. I have to pull the cable from the TV when I want to listen to
music!

Anyone have experience with a good solution?

Typical ground loop hum. One solution is to get a ground isolator for the
cable line. There are others - search for cable ground loop:

http://www.google.com/search?hl=en&q...able+gro und+

whosbest54
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[Eeyore]

whosbest54 wrote:

lid says...

I switched from satellite to cable, and that cable going into the back
of the TV has introduced a terrible hum into my stereo/surround
system. I have to pull the cable from the TV when I want to listen to
music!

Anyone have experience with a good solution?

Typical ground loop hum.

Agreed. Happens all the time.

Graham

[ChrisCoaster]

On Sep 14, 12:17*pm, Eeyore
wrote:
whosbest54 wrote:
says...

I switched from satellite to cable, and that cable going into the back
of the TV has introduced a terrible hum into my stereo/surround
system. *I have to pull the cable from the TV when I want to listen to
music!

Anyone have experience with a good solution?

Typical ground loop hum.

Agreed. Happens all the time.

Graham
________________
Here's what I did to eliminate it. First of all, it helps to have a
properly grounded receptacle within 4 feet of the cable jack on the
wall.

1. Buy some 18 or 16AWG stranded wire from a Radio Shack(remember,
we're grounding a coax signal line here - not a washing machine.)
2. Cut a piece slightly longer than the distance between the
receptacle & the cable jack.
3. Strip 2" from the end going around the back side of the cable jack
plate between it and the washers holding the jack to the plate.
4. Strip 1" from the end going aroud the screw holding the receptacle
plate to the receptacle.
5. I think you can figure out how to get the wire around both items -
the female/female cable bridge at one end and the receptacle plate
screw on the other.
6. Remount the cable jack & plate to the wall.

In my case - hum gone, tighter bass, clearer sound overall, especially
on my HT system.

Let me know how this works for you.

-ChrisCoaster

[pancake]

On Sun, 14 Sep 2008 14:27:48 GMT, dizzy wrote:


I switched from satellite to cable, and that cable going into the back
of the TV has introduced a terrible hum into my stereo/surround
system. I have to pull the cable from the TV when I want to listen to
music!

Anyone have experience with a good solution?

Get (2) 75 to 300 Ohm baluns and tie them back to back.
Pancake

[jamesgangnc]

Quick and dirty, get one of those cheap 3 prong to 2 prong plug adapters and
use it on your satellite receiver. You probably have a huge ground loop
because of the satellite being grounded.

"dizzy" wrote in message
...

I switched from satellite to cable, and that cable going into the back
of the TV has introduced a terrible hum into my stereo/surround
system. I have to pull the cable from the TV when I want to listen to
music!

Anyone have experience with a good solution?

[[email protected]]

Pancake wrote:
On Sun, 14 Sep 2008 14:27:48 GMT, dizzy wrote:

I switched from satellite to cable, and that cable going into the back
of the TV has introduced a terrible hum into my stereo/surround
system. I have to pull the cable from the TV when I want to listen to
music!

Anyone have experience with a good solution?

Get (2) 75 to 300 Ohm baluns and tie them back to back.
Pancake


Won't work ... the grounds are tied together internally
in the commercial baluns.

It would work if they were not so tied, but so would a
plain bifilar transformer.

Doug McDonald

[Richard Crowley]

"jamesgangnc" wrote ...
Quick and dirty, get one of those cheap 3 prong to 2 prong plug adapters
and use it on your satellite receiver. You probably have a huge ground
loop because of the satellite being grounded.

The ground loop is caused by the ground on the *cable*, not
the ground on the receiver. Lifting the local safety ground on
the receiver ("cable box") is a potentially dangerous "solution".
People have reported well over 50VAC potential on the cable
shield, and that is safely grounded by the cable box green-wire
ground connection.

The solution is to break the hard ground connection on the
cable itself by using an isolation transformer.

The problem is caused by the practice of grounding the cable
system back hundreds or thousands of feet upstream, but with
no "local" reference to ground.

[[email protected]]

Richard Crowley wrote:
"jamesgangnc" wrote ...
Quick and dirty, get one of those cheap 3 prong to 2 prong plug adapters
and use it on your satellite receiver. You probably have a huge ground
loop because of the satellite being grounded.

The ground loop is caused by the ground on the *cable*, not
the ground on the receiver. Lifting the local safety ground on
the receiver ("cable box") is a potentially dangerous "solution".
People have reported well over 50VAC potential on the cable
shield, and that is safely grounded by the cable box green-wire
ground connection.

The solution is to break the hard ground connection on the
cable itself by using an isolation transformer.

The problem is caused by the practice of grounding the cable
system back hundreds or thousands of feet upstream, but with
no "local" reference to ground.



I had this problem and finally solved it by using a DC isolated
cable connection. I got two female F jacks and connected the
center pins together with one .001 microfarad tiny size
chip capacitor and the grounds of the two jacks together
through 6 somewhat larger 150 pf chip capacitors equally
spaced around the circumference; I soldered them to some
sheet copper held on by two nuts. This was put between the cable
and the box using an extra one foot long cable.

Doug McDonald

[dizzy]

ChrisCoaster wrote:

Here's what I did to eliminate it. First of all, it helps to have a
properly grounded receptacle within 4 feet of the cable jack on the
wall.

1. Buy some 18 or 16AWG stranded wire from a Radio Shack(remember,
we're grounding a coax signal line here - not a washing machine.)
2. Cut a piece slightly longer than the distance between the
receptacle & the cable jack.
3. Strip 2" from the end going around the back side of the cable jack
plate between it and the washers holding the jack to the plate.
4. Strip 1" from the end going aroud the screw holding the receptacle
plate to the receptacle.
5. I think you can figure out how to get the wire around both items -
the female/female cable bridge at one end and the receptacle plate
screw on the other.
6. Remount the cable jack & plate to the wall.

In my case - hum gone, tighter bass, clearer sound overall, especially
on my HT system.

Let me know how this works for you.

So... Just short-out ground-loop, in other words.

Preliminary experiment (sticking one end of the wire into the Ground
hole of the outlet and pressing the other against the outside of the
cable's connector) showed a massive reduction in hum, but there's
still some noise getting through - some higher-frequency, buzzy junk.

I think I may do your trick *and* buy an isolation transformer.

[Richard Crowley]

"dizzy" wrote ...
So... Just short-out ground-loop, in other words.

Preliminary experiment (sticking one end of the wire into the Ground
hole of the outlet and pressing the other against the outside of the
cable's connector) showed a massive reduction in hum, but there's
still some noise getting through - some higher-frequency, buzzy junk.

I think I may do your trick *and* buy an isolation transformer.

If the ground loop is bad enough, you may find a way of tapping
into that "free" power. It may be enough to power the cable box! :-)

[Chris Hornbeck]

On Mon, 15 Sep 2008 06:57:00 -0700, "Richard Crowley"
wrote:

The ground loop is caused by the ground on the *cable*, not
the ground on the receiver. Lifting the local safety ground on
the receiver ("cable box") is a potentially dangerous "solution".
People have reported well over 50VAC potential on the cable
shield, and that is safely grounded by the cable box green-wire
ground connection.

The solution is to break the hard ground connection on the
cable itself by using an isolation transformer.

The problem is caused by the practice of grounding the cable
system back hundreds or thousands of feet upstream, but with
no "local" reference to ground.

To the OP: please listen to Richard's advice. Never lift
a safety ground, *especially* when a better solution is
available easily.

There have been two good solutions to your problem already
posted: 1) break the cable's ground path with an isolation
device - several kinds are available. 2) minimize the length
of the ground loop by locally connecting cable ground to
Edison safety ground. Both work and both are safe for your
family.

The second option is also built into most "lightning protection"
widgets that include cable protection. Their cable ground is
hard-wired to their Edison ground.

All the best fortune,
Chris Hornbeck

[ChrisCoaster]

On Sep 15, 8:38*pm, "Richard Crowley" wrote:
"dizzy" *wrote ...

So... *Just short-out ground-loop, in other words.

Preliminary experiment (sticking one end of the wire into the Ground
hole of the outlet and pressing the other against the outside of the
cable's connector) showed a massive reduction in hum, but there's
still some noise getting through - some higher-frequency, buzzy junk.

I think I may do your trick *and* buy an isolation transformer.

If the ground loop is bad enough, you may find a way of tapping
into that "free" power. It may be enough to power the cable box! :-)
________________
Or that flux-capacitor you've been hangin onto since the 80s!

[Tomi Holger Engdahl]

dizzy writes:

I switched from satellite to cable, and that cable going into the back
of the TV has introduced a terrible hum into my stereo/surround
system. I have to pull the cable from the TV when I want to listen to
music!

Sounds like a typical ground loop problem:

Ground loop problems and how to get rid of them
http://www.epanorama.net/documents/g...oop/index.html

Anyone have experience with a good solution?


Installing an isolator to antenna conenction will solve the problem well
http://www.epanorama.net/documents/g..._isolator.html



--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/