atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Telecom Service & Providers Relocating Arris box for CATV telephone service

Have the customer call Comcast and inquire as to the costs? I would think a TR wouldn't be much. Yes you don't get the work, but you won't get blamed if it doesn't work or the calls are choppy, etc.

We did the move yesterday and everything went just fine. The new apartment was actually served from the same set of riser taps that the original one was.

The reason that the customer asked us to do this was because Comcast had told them that there was a three-week window to schedule the dispatch of a technician. They were more than willing to pay, but three weeks was too much of a delay.

I got a chance to scope out the riser and tap arrangements for this complex of three high-rise apartment buildings. Yes, each building does have a physical street address, but they all share a single telephone/CATV room in the basement of one of them, so a nodal issue in any apartment won't be a problem.

Thanks for the reminder about 911, Hawk. Didn't think about that one. I'm sure that the customer can change this information with Comcast for minimal (if any) expense.

Thanks for the reminder about 911, Hawk. Didn't think about that one. I'm sure that the customer can change this information with Comcast for minimal (if any) expense.

It was me Ed. I don't believe the customer can change the E911 location for liability reasons. That information is entered when the modem is installed by the cable tech at the physical address and the account is activated.

-Hal

The differing taps are so that they can compensate for cable losses in the outside plant, and maintain a consistent level to each customer. The tap attenuation decreases the farther you get from the last amplifier on the trunk cable.

Lets say that you have a trunk amplifier that puts out +30db, and you want to maintain a level of 0db at the customer set. Lets say for the sake of argument that 1/2" hardline has a loss of 1db/100', and RG6 has a loss of 6db/100'.

Lets also assume that you are trying to maintain 0db +/-2db, and that the average drop length to a customer is 75', with a splitter, and 50' drops to the sets. Taps off the trunk cable are every 100'. Lets assume that the splitters have 4.5db loss.
That's ~12db loss from the tap to the set.

If your first tap is at the amplifier output, you would need ~18db of attenuation at that tap to feed the first set of drops, 17db at the next tap 100' downstream, 16, 15, etc.. Taps come in 3db increments, so you would probably have 17, 17, 15, 15, etc.
Plug-in attenuators are also available, which can be used to compensate for asymmetric drop lengths, etc.

The large tap housings used on hardline have interchangeable inserts, so they sometimes put a couple housings in series, with different tap values. There are also large housings which can accommodate half a dozen tap plates for structured wiring applications such as apartment houses.