[Greg Grainger]

A while back, there was a discussion about the hum that leaks in to stereo
gear from the TV cable. Several people mentioned a device that goes in
line with the TV cable to lift the ground, eliminating the hum.

Would some nice person please re-post the info on that device? The name of
it, where it can be obtained? (on-line or otherwise)

Many thanks in advance,
Greg.
--
Greg Grainger grainger(at)vex.net

'What a world of gammon and spinach it is, though, ain't it?'
- Miss Mowcher

[Peter Wieck]

On Sep 17, 9:49*am, (Greg Grainger) wrote:
A while back, there was a discussion about the hum that leaks in to stereo
gear from the TV cable. Several people mentioned a device that goes in
line with the TV cable to lift the ground, eliminating the hum.

Would some nice person please re-post the info on that device? The name of
it, where it can be obtained? (on-line or otherwise)

Many thanks in advance,
Greg.
--
* * * * * *Greg Grainger * * * * * * * * * grainger(at)vex.net

* * *'What a world of gammon and spinach it is, though, ain't it?'
* * * * * * * * * * * * * * * * * * * * * * *- Miss Mowcher

I would think that a good shield-ground would get rid of hum - as long
as there is no difference in potential between components?

In any case, we have a surge-protector that includes a cable in/out
function that also serves as a filter. A stand-alone unit would be:

http://www.shopperschoice.com/item_n...source=froogle

Here is a combination unit:

http://www.skycraftsurplus.com/index...ROD&ProdID=491

There are others.

Peter Wieck
Melrose Park, PA

[John Stone]

On 9/17/08 10:27 AM, in article , "Peter
Wieck" wrote:

On Sep 17, 9:49*am, (Greg Grainger) wrote:
A while back, there was a discussion about the hum that leaks in to stereo
gear from the TV cable. Several people mentioned a device that goes in
line with the TV cable to lift the ground, eliminating the hum.

Would some nice person please re-post the info on that device? The name of
it, where it can be obtained? (on-line or otherwise)

Many thanks in advance,
Greg.
--
* * * * * *Greg Grainger * * * * * * * * * grainger(at)vex.net

* * *'What a world of gammon and spinach it is, though, ain't it?'
* * * * * * * * * * * * * * * * * * * * * * *- Miss Mowcher

I would think that a good shield-ground would get rid of hum - as long
as there is no difference in potential between components?

In any case, we have a surge-protector that includes a cable in/out
function that also serves as a filter. A stand-alone unit would be:

http://www.shopperschoice.com/item_n...n-APC-Coaxial-
Cable-Surge-Protector_item_379741.html?source=froogle

Here is a combination unit:

http://www.skycraftsurplus.com/index...ROD&ProdID=491

I think he's trying to isolate the cable ground from the audio system
ground. This is a common problem that causes ground loop hum in the system
because the 2 grounds are often at different potentials. The simplest
approach is to insert an isolation transformer in the cable line. Here's one
product that will do the job:

http://www.audioxpress.com/bksprods/.../pj-vrd1ff.htm

I'm sure there are others.

[[email protected]]

A while back, there was a discussion about the hum that leaks in to stereo
gear from the TV cable. Several people mentioned a device that goes in
line with the TV cable to lift the ground, eliminating the hum.

Would some nice person please re-post the info on that device? The name of
it, where it can be obtained? (on-line or otherwise)

I don't know to what discussion you refer. One method is to use back to
back balums. I seem to recall radio shack has one already just for this
purpose.

[Peter Wieck]

On Sep 17, 4:32*pm, John Stone wrote:
On 9/17/08 10:27 AM, in article , "Peter





Wieck" wrote:
On Sep 17, 9:49*am, (Greg Grainger) wrote:
A while back, there was a discussion about the hum that leaks in to stereo
gear from the TV cable. Several people mentioned a device that goes in
line with the TV cable to lift the ground, eliminating the hum.

Would some nice person please re-post the info on that device? The name of
it, where it can be obtained? (on-line or otherwise)

Many thanks in advance,
Greg.
--
* * * * * *Greg Grainger * * * * * * * * * grainger(at)vex.net

* * *'What a world of gammon and spinach it is, though, ain't it?'
* * * * * * * * * * * * * * * * * * * * * * *- Miss Mowcher

I would think that a good shield-ground would get rid of hum - as long
as there is no difference in potential between components?

In any case, we have a surge-protector that includes a cable in/out
function that also serves as a filter. A stand-alone unit would be:

http://www.shopperschoice.com/item_n...Conversion-APC...
Cable-Surge-Protector_item_379741.html?source=froogle

Here is a combination unit:

http://www.skycraftsurplus.com/index...ROD&ProdID=491

I think he's trying to isolate the cable ground from the audio system
ground. This is a common problem that causes ground loop hum in the system
because the 2 grounds are often at different potentials.

Yeah - that is always a problem. And you are very likely exactly
right. Writing for myself, I am pretty nutso about ground loops - and
so only referred to the need in passing...

The simplest
approach is to insert an isolation transformer in the cable line.

I found one of those - but when I read "noise", I probably went too
technical and looked for an overkill solution.

Here's one
product that will do the job:

http://www.audioxpress.com/bksprods/.../pj-vrd1ff.htm

I'm sure there are others.- Hide quoted text -

KISS applies.

Thanks!

Peter Wieck
Melrose Park, PA

[Paul G.]

On 17 Sep 2008 22:32:28 GMT, wrote:

A while back, there was a discussion about the hum that leaks in to stereo
gear from the TV cable. Several people mentioned a device that goes in
line with the TV cable to lift the ground, eliminating the hum.

Would some nice person please re-post the info on that device? The name of
it, where it can be obtained? (on-line or otherwise)

I don't know to what discussion you refer. One method is to use back to
back balums. I seem to recall radio shack has one already just for this
purpose.

Baluns DO NOT isolate from ground. You can use the same core and
wind a bifilar transformer yourself. Chances are it won't have the
best frequency response (poor UHF or high channel cable response), so
if you not into the DIY thing, you'll need to pay the 60 dollars or so
for an isolation transformer. Making cable transformers has many of
the same issues that plague tube transformers. I had the same hum
problem a number of years ago, and made my own. It solved the hum
problem.
The hum comes from 60 Hz ground currents flowing because the cable
ground and your equipment ground (from your receptacle) are at
different voltages. I've had a bit of a "buzz" from putting my fingers
between the cable and power grounds.
There is also a way to do this with capacitors, but I wouldn't
recommend it, since the wrong circuit or construction will give you
interference issues.

-Paul G.