Guys,
This site has been a great source of info for me over the last year or so and I now have a problem I need some recommendations/input/new ideas about.
In a not so small nutshell:
My tale of ground loops, scrolling bars and herringbones.
Seems over the last 4 months or so (my DVR would say around mid-November) my home cable distribution system developed what looks to be a ground loop causing was were at first horizontal bands of varying light and dark sections scrolling through the pictures.
My system is Comcast analog only fed first off the amp in the box in the front yard. I had, at first, an OnQ 3X8 amplifier that boost the signal only to make up the loss in dividing it (unity, they call it), with only the cable in and 5 outputs to various configurations (tv's with DVD players, vcr, etc.).
First I called Comcast to look at the signal in. I long suspected the cable in was kaput, due to various reasons, mostly my digging around the yard planting bushes, etc.
This guys sees it: in the signal at the street, says he will put in a ticket to get it fixed. After three weeks I call back and they, Comcast insists on another service call, so OK, I wait for him the next Saturday.
Second guy cannot find the defect on the signal outside and asks to see my setup.
Anyway, he jumps around the amp directly to my primary TV and the bands disappear.
It's your amp doing it, he says.
OK, I can buy that since it is 1999 vintage.
So I buy and amp, new off EBay and plug it in and the bands disappear, but now I have wavy lines in a herringbone fashion on all TVs.
So now I start doing my homework and find out I have a ground loop problem, but I'm unsure if it is in the electrical system of the house, the cable system or both.
Now I'm wondering it if has always been in the signal from the street and I just don't see it unless its amped.
Since then I have :
1. powered the amp from another circuit in the house - still interference
2. fed the amped distribution system directly from a DVD player in the amp to the TV - still have the interference ( this is the outlier that makes me think the problem is on my wiring.
3. add a splitter prior to the amp to feed the primary TV directly (looked good no wavies), and all the other TVs have the wavy lines, but otherwise good color.
So I called Comcast a third time and he runs a new line from the street to the house (outside box where the ground originates) - still interference
And Jumped the new line directly to the amp - still interference
He installs a tree of splitters and takes the amp out of the system altogether.
My last TV in the litter, upstairs, is bearly watchable, but the others are OK. I'll have to work the amp back in over time, since the new room upstairs will need a TV soon.
So I then take the amp upstairs to the runt of the litter upstairs to see if the amp will work in a different location on a single TV. It doesn't help the picture much, btu it does put the wavy lines back in the TV. I do think I looked at one other TV at this time and it did not have the wavy lines ( no backfeed?).
So I call my Dad the electrician and he suggests I lift the ground on the cable system and see if it clears - it doesn't, but it was a great suggestion.
He is sure the problem is in the cable wiring, not the electrical wiring....
So now I'm back to developing a new approach.
And all comments and suggestions are welcome.
Does this sound like a problem in the cable distribution wiring or in the electrical wiring?
I'm now down to pulling the system apart, checking all the plates and cables behind them for bad connectors and loose fittings, etc. and anything else that comes to mind.
In fact, As I'm watch the superbowl the picture quality just decided to go south and I believe I see banding in the picture without any amps in the system....
Anyone else out ther had to attack a ground loop problem?
If so, what logic did you use and what would you suggest??
maybe I have two problems going on at the same time...crappy Comcast signal and a ground loop....
thanks,
news_watch
This site has been a great source of info for me over the last year or so and I now have a problem I need some recommendations/input/new ideas about.
In a not so small nutshell:
My tale of ground loops, scrolling bars and herringbones.
Seems over the last 4 months or so (my DVR would say around mid-November) my home cable distribution system developed what looks to be a ground loop causing was were at first horizontal bands of varying light and dark sections scrolling through the pictures.
My system is Comcast analog only fed first off the amp in the box in the front yard. I had, at first, an OnQ 3X8 amplifier that boost the signal only to make up the loss in dividing it (unity, they call it), with only the cable in and 5 outputs to various configurations (tv's with DVD players, vcr, etc.).
First I called Comcast to look at the signal in. I long suspected the cable in was kaput, due to various reasons, mostly my digging around the yard planting bushes, etc.
This guys sees it: in the signal at the street, says he will put in a ticket to get it fixed. After three weeks I call back and they, Comcast insists on another service call, so OK, I wait for him the next Saturday.
Second guy cannot find the defect on the signal outside and asks to see my setup.
Anyway, he jumps around the amp directly to my primary TV and the bands disappear.
It's your amp doing it, he says.
OK, I can buy that since it is 1999 vintage.
So I buy and amp, new off EBay and plug it in and the bands disappear, but now I have wavy lines in a herringbone fashion on all TVs.
So now I start doing my homework and find out I have a ground loop problem, but I'm unsure if it is in the electrical system of the house, the cable system or both.
Now I'm wondering it if has always been in the signal from the street and I just don't see it unless its amped.
Since then I have :
1. powered the amp from another circuit in the house - still interference
2. fed the amped distribution system directly from a DVD player in the amp to the TV - still have the interference ( this is the outlier that makes me think the problem is on my wiring.
3. add a splitter prior to the amp to feed the primary TV directly (looked good no wavies), and all the other TVs have the wavy lines, but otherwise good color.
So I called Comcast a third time and he runs a new line from the street to the house (outside box where the ground originates) - still interference
And Jumped the new line directly to the amp - still interference
He installs a tree of splitters and takes the amp out of the system altogether.
My last TV in the litter, upstairs, is bearly watchable, but the others are OK. I'll have to work the amp back in over time, since the new room upstairs will need a TV soon.
So I then take the amp upstairs to the runt of the litter upstairs to see if the amp will work in a different location on a single TV. It doesn't help the picture much, btu it does put the wavy lines back in the TV. I do think I looked at one other TV at this time and it did not have the wavy lines ( no backfeed?).
So I call my Dad the electrician and he suggests I lift the ground on the cable system and see if it clears - it doesn't, but it was a great suggestion.
He is sure the problem is in the cable wiring, not the electrical wiring....
So now I'm back to developing a new approach.
And all comments and suggestions are welcome.
Does this sound like a problem in the cable distribution wiring or in the electrical wiring?
I'm now down to pulling the system apart, checking all the plates and cables behind them for bad connectors and loose fittings, etc. and anything else that comes to mind.
In fact, As I'm watch the superbowl the picture quality just decided to go south and I believe I see banding in the picture without any amps in the system....
Anyone else out ther had to attack a ground loop problem?
If so, what logic did you use and what would you suggest??
maybe I have two problems going on at the same time...crappy Comcast signal and a ground loop....
thanks,
news_watch
