Cable signal and interference

CalWldLif

I am a Charter subscriber in SoCal Ca.
Just Digital HD, no phone or internet.

In Dec 10' I purchased a HD TV.
I was getting Digital SD with a STB.
I plugged the cable in the TV and scanned for
channels. Found the main Networks and enjoyed
a beautiful HD pic.
after a couple months/in Feb, I upgraded to A HD STB.
enjoyed the added channels in HD.
So far so good.

Approx a month later, end of March, there was
an electrical power outage due to a power co upgrade.
I started noticing a reduced quality pic and some kind of distortion.
Attached pic is exaggerated, but the black horizontal lines are what I see in faces as the persons head moves, not action moves but regular talking type moves. The lines are not as thick, but definitely
black lines.


It was mainly on the Public Network channels,
CBS, NBC, ABC and FOX. CBS was the worst.
I tried straight cable, no STB and still had it.
I tried straight cable on a SD TVset.
I tried the HD STB with HDMI, Component.
It did not matter.
Same interference.
I replaced splitter, remove splitter, changed
house junction, added amp.
Same problem.

The issue has now started showing up on most channels.

Here are some pics of the STB dia screens.
Can someone explain the info?
CBS was -7 db and others were+3db.
So I had a 10DB swing. Is this normal?
channel 2 CBS

here is 11 Fox


some other channels




Past experience with Charter support left me
with a bad taste.
I had 4 techs out in the past and had to contact
the Boss about it.

I am hoping to learn about Qam db levels vs FDC db levels.
Also the number of corrected blocks.
And any way I can get Charter to
see the problem and correct it.

Most techs I have come to the house just change splitters.

Loves2Watch

Good luck with Charter and their compression. An outdoor antenna would serve your needs much better.

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CalWldLif

that is what I do not understand.
Even when putting the cable straight
into an old analog TV, i get the lines.
My cable still sends an anolog feed for
basic stations. How can they compress
that feed?

Loves2Watch

They compress everything they have...then send it along, some more than others and it is allowed. OTA, received from a home antenna is the least compressed broadcast signal available.

__________________
It's always time for pie
Live everyday as if it was your last and plan on living forever...

Scottnot

Agree, doesn't look like the results of compression.
And the signal levels look decent (-15 to +20 is "normal" range).
What it looks like is one of the many forms of harmonic distortion that can occur in cable system amplifiers; I'd guess that one of the amps went south either coincident with or because of the power company work. Your neighbors should be seeing similar loss of quality, and the cable co. service techs ought to be able to identify the problem.

__________________
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Charles Krug, 1978 Vintage Selection, Napa Valley Cabernet Sauvignon
Beringer, 1980, Napa Valley Cabernet Sauvignon Port
Morano, 1980 Vintage Port
Beaulieu Vinyards, 1982 Napa Valley Cabernet Sauvignon
Stratford, 1983 Merlot
Chateau La France, 1986 St. Emilion
Sutter Home, 1982 Napa Valley Zinfandel

The lonesome sipper

CalWldLif

thank you for the info.
when you say a tech can id the issue,
is that with tech test meters?
I ask because Charter techs that have come in the past, did not have test equipment with them. Seems a higher level tech was always needed.
first the installer type. "bad splitters"
Then the signal meter type, "tap out of spec"
Then the tap tech who needed a senior tap tech to do the work.

Then always the, "it is only a couple channels"

I can't rely on a visual tech and getting the one with equipment that can actually use it is rare.

Any idea of the number of people
that the "amplifier" serves?
From the amount of Dishes on peoples houses, I really do not know
just how many people have Charter.


thanks again.

ITALIAN926

Sounds like you need a new provider...

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Former FiOS technician
My Family Room Pic #1

My Family Room Pic #2

Scottnot

No, the home service techs won't have equipment to directly measure specified amplifier distortions such as cross modulation, second order and triple beat.
But one would hope that they are able to see when something is wrong and call in the appropriate next level service personnel.

Odd isn't it that the mentioned harmonically generated distortions tend to be worse on some channels than others (higher channels in the case of cross mod and second order, and more random in the case of triple beat.

Hard to say. In the case of a trunk or bridger amp it could be hundreds; in the case of a distribution amp it could be as few as three or four.

p.s.
I went back and read your intro post where you mention that the "lines" tend to appear more during motion sequences.
That does sound more like a compression issue rather than distortion.

Whether it's distortion, compression, or a combination of both, the situation you've described would be understandably annoying to anyone familiar with decent quality HD television.
Sounds like you're going to have to continue to escalate your complaint with Charter to get a satisfactory resolution;
or at least an honest admission that they aren't able to deliver a decent quality HD picture to your location.

Good luck, and please keep us posted on our progress and outcome.

__________________
------------------------------------------------------------------------------------------------------
Charles Krug, 1978 Vintage Selection, Napa Valley Cabernet Sauvignon
Beringer, 1980, Napa Valley Cabernet Sauvignon Port
Morano, 1980 Vintage Port
Beaulieu Vinyards, 1982 Napa Valley Cabernet Sauvignon
Stratford, 1983 Merlot
Chateau La France, 1986 St. Emilion
Sutter Home, 1982 Napa Valley Zinfandel

The lonesome sipper

CalWldLif

Thanks for the reply.
Good news and bad.
Seems last night there was an outage of sorts at midnight.
All channels were cutting in and out. Like someone was unscrewing a cable and rescrewing.
Went to bed and today it is
better.
Bad news, the helplessness of
having to rely on a tech to "see" something that came and went through out the day
and get them to believe what i describe and be willing to
do something about it.