View Full Version : Will digital cable get rid of ghosting?


TheGSRGuy
08-16-09, 09:11 PM
Long story made short, the wiring in my apartment building sucks. There's two different types and gauges of cable between me and the distribution box on the floor. Comcast's own technician (not a contractor) acknowledged it and put in a work order to get it fixed, but the dumbass contractors came and decided a 9dB loss in 100 yards of wiring is "acceptable".

I currently get the "basic analog" cable service from them. It runs into a TiVo HD. On some of the channels, I get ghosting or color banding. It's noticeable on shows like The Simpsons where you have big blocks of solid color.

Is moving to digital cable going to fix this? My OTA HD coverage is really good since I'm only a few miles from the Sears Tower and have minimal obstruction. Canceling altogether isn't the end of the world either.

Ken H
08-16-09, 11:46 PM
Going to digital will remove all analog artifacts, like you've described. But, you'll have to have acceptable digital signal for a digital box to work correctly.

kenglish
08-17-09, 08:50 AM
Sounds like you have multiple problems.

"Ghosting" in Cable TV usually refers to ingress of the analog OTA signal on the same channel as it is being broadcast, causing a double image. This would only occur on local channels. Since there should be no full-power stations broadcasting analog now, you should not be seeing any ingress-caused "ghosts".

There is another type of "ghosting" called "Halos", which is due to reflections of the signal within the cable lines. This usually causes very short-spaced "ghosts", which closely match the primary signal's outlines....a "halo" effect.

If you are seeing funny-looking beats, especially in the color areas of the picture, there is probably distortion ("cross-modulation") coming from the amplifiers. Other problems may be due to improper levels in the system, even too-low levels going in to the amps.

If the wiring is this bad, you'll likely have problems with many of the Digital Cable channels as well. Your Cable company should call in a better contractor.

arxaw
08-17-09, 12:40 PM
I would drop cable if they can't fix the PQ problems.

TheGSRGuy
08-17-09, 04:37 PM
It's color banding -- strange horizontal blocks of coloring that's a bit "off". I notice it more on the SD stuff on HD channels, i.e. old episodes of The Simpsons broadcast on FOX-HD.

Like I said, the Comcast tech noticed a 9dB loss between the drop in my apartment and the distribution closet. There's also two different gauges of wiring in the wall for whatever reason -- RG6 at one point, "RG6 quad" at another. The dumbass contractors likely ran out of RG6-quad and just switched to whatever else they had left, he thinks.

RCN is the only other alternative, really.

Ken H
08-17-09, 07:17 PM
It's color banding -- strange horizontal blocks of coloring that's a bit "off". I notice it more on the SD stuff on HD channels, i.e. old episodes of The Simpsons broadcast on FOX-HD.

Like I said, the Comcast tech noticed a 9dB loss between the drop in my apartment and the distribution closet. There's also two different gauges of wiring in the wall for whatever reason -- RG6 at one point, "RG6 quad" at another. The dumbass contractors likely ran out of RG6-quad and just switched to whatever else they had left, he thinks.


The difference between RG-6 & RG-6 Quad is only more shielding on the cable, which for your application is not a factor in signal quality.