Coax video cabling FREE cabling and networking Helpdesk
 Question by Brian McKay posted 04 Jan 2006
 Coax video cabling
I am a general contractor, we recently installed coax in a fairly large residential home, I have tested all lines with a tester everything looks good. The owner tell me 2 channels do not work that used to work with their old cable. About 100 channels work fine and look real clear - Is it possible that two channels might not work when everything else seems to be fine??? Help
 Answer by Joseph Golan posted 05 Jan 2006
Dear Brian,

Sure anything is possible but this serario is unlikely and whould require additional information to help diagnose.

What does the custiomer mean by "do not work": are they fuzzy; not coming in at all; scrambled?

Why was the coax changed to begin with?

Is this happening at the new outlets as well as the old or all of them?

How many drops are being split off the service?

Is there a line amplifier before the splitter(s)?

What kind of a tester did you use?

Not all Coax is the same. Most CATV providers require a high grade (high-end frequency) of RG-6 with what is known as "Quad Shielding". It is also possible that a splitter may be the problem as they are also rated with a frequency range and it may be that these two channels are in the higher frequencies.

You haven't said in your message as to where this project is, the name of the CATV service or what channels (number and name) are giving you the problem. I would also need to know if the TV set that they are missing at is using a cablebox or is directly hooked up.

Last, if these are part of a premium cable package, are you sure that your client has subscribed to these additional services.

Please either post back to the site (with my name in the subject) or email me at

Joseph Golan, RCDD

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