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Comcast - Grainy picture... analog channels

713 Views 6 Replies 5 Participants Last post by  GoIrish

I'm in the Newton, MA area with Comcast cable. The lower channels are grainy and not coming in clear the way I expect cable to. The higher channels, On Demand and the HD channels come in great... but not the CATV channels. I would have Comcast come out and fix it but that would cost an additional $25 and they can't get here for another week.

So, I know that the problem is probably because of a weak signal. I picked up the Radio Shack Sat/TV/FM In-Line Signal Amplifier but it didn't make a difference. (50 - 2,200 MHz @ 10 dB MIN) Is there a way I can find out why this signal is coming in weak? Wouldn't the HD cable box automatically boost the signal? Is this not a matter of a weak signal but something else?

If someone could point me in the right direction or help me out that would be great.

- Brian
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do you have an HDTV? did you just hook it up and figure this out, or did it just start happening with a currrent set-up?
actually, i think it is the (motorola) digital STB. i have comcast in NJ and i can't stand watching the lowed SD cable channels thru the STB. try running straight into your TV- if that picture is better then use the bypass connector on the STB and run 2 inputs to your TV- one for SD and one for digital. you'll of course need to use the component out for the digital.
Double post?

Go into the cable box setup and set the 480i mode to "passthrough".

This will keep the SD analog crap from getting upconverted to 1080i output and keep it at 480i. Upconversion upcoverts the picture as well as the 'garbage'.
Actually, it probably isn't signal strength. I'm surprised to hear they will charge you a service call. Most Comcast systems don't. That is one of the former ATT systems so maybe they still have some old policies in place.

Low end signal problems are usually a bad fitting. Broader ranges of analog channels showing grain is more likely a bad section of cable in the home or a bad outside cable from the street.

It could still be a signal strength issue but not as likely as the first two above.

You need a service call. As Andy told Aunt Bee, call the man... (sorry, obtuse old TV show reference). If you already have one scheduled, great. If they find a problem in the house related to your internal wiring you may get a service call charge. If they find a problem outside the house then that is their property and you won't be charged.

Good luck with this and let us know what happens.


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Yeah, I have the Motorola STB... on an HDTV. I understand that when the image is stretched it isn't going to look as sharp but this isn't the case. It is actual grain on the screen.

I know that it isn't a matter of the area having the same problem... the people who live a floor above me have regular digital cable but the analog channels come in great.

I did a crummy job on cutting/crimping some of the wires leading up the TV... so I'm going to go back and crimp the wires right and see if that makes a difference.

Is there anything I can do to test the line to see if enough of the signal is getting through?
If you're cutting your own fittings and do not have the proper equipment, your odds that the problem is with this wiring goes way up.

I will say again it most likely is not signal strength.


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