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OT : How to find tv points in pre wired house
Barkalarr - 25/2/13 at 10:02 PM

Here's a problem for the collective.

A friend of mine has moved into a new house and there are TV points in every room. There's a loom in the attic which is not labelled up at all. One bit of the loom is plugged into one booster, while the rest of the loom is plugged into another booster. There are 2 aerials in the loft.

The goal here is to pipe their sky to the kids playroom upstairs over the existing coax (they have not got HD) from the lounge downstairs, so we need to identify which cable in the attic is which room.

The question is; Whats the best locost way to do this?
Neither of us have a cable identifier (the thing that sends a pulse along the coax) but I do have a multi meter.

I did think about creating an aerial connector we can plug into each socket with a short on it (core connected to shield) and using the multi meter to look for the short - I'm reluctant to do this in case we blow up either booster?

I know how to wire it all up, I just need to identify what coax goes to what room.

Any ideas?


puma931 - 25/2/13 at 10:11 PM

Disconnect all devises from the coax plugs. The someone in the bedroom checks for resistance and someone in the loft bridges the centre and outside of each unplugged lead. When you get zero resistance you have found the cable for the room.


Ian D - 25/2/13 at 10:15 PM

Before you go too far check that the coax for TV and sky have the same characteristics. Ie impedance etc.


Ian


daniel mason - 25/2/13 at 10:33 PM

JUST CONNECT ONE WIRE UP AT A TIME IN LOFT AND GO ROUND EACH ROOM WITH A TV UNTIL YOU GET SIGNAL.
PROCESS OF ELIMINATION.LABELLING AS YOU GO. NO POINT REMOVING THE CO AX PLUGS AND SHORTING CONUCTOR TO BRAIDING AS YOULL ONLY HAVE TO PUT THEM BACK ON AGAIN


spiderman - 25/2/13 at 10:38 PM

Put a tv into the room you want to identify, switch it on, unplug the coaxial cables in the attic one at a time until you lose the picture, you have then identified the coax for that room. The bridging of the coax, inner and outer, and testing with a multimeter works but the former method only requires one person as you will hear the tv channel in the loft if you turn the volume up and will be able to tell when you loose the signal.


Barkalarr - 26/2/13 at 07:50 AM

So we tried doing this with a television, but the signal seems to be strong in our area so you don't actually need an aerial to get a picture - just the length of coax in the attic is good enough to see a picture.
We unplugged everything and three of the televisions were still working fine - only one of them went off which is why I wanted a different way to trace the cable.


Macbeast - 26/2/13 at 08:59 AM

You won't blow up a booster by putting a short on an output.


Peteff - 26/2/13 at 10:17 AM

quote:
Originally posted by Barkalarr
So we tried doing this with a television, but the signal seems to be strong in our area so you don't actually need an aerial to get a picture - just the length of coax in the attic is good enough to see a picture.



What even on a digital signal, is the loom in the loft definitely not part of a system plugged in somewhere else ?


Barkalarr - 26/2/13 at 10:20 AM

No as far as we could tell.

I unplugged the aerial from the wall socket - so there was only a 4 ft fly lead and there was still a picture on the screen. It only went off completely when you remove all fly leads so the television has nothing plugged into it.

I know... bonkers eh?

[Edited on 26/2/13 by Barkalarr]


daniel mason - 26/2/13 at 06:18 PM

connect the sky box up downstairs. connect the existing wire in lounge (which you want to run sky up to loft with) to RF1 terminal on back of sky box.
identify yhis wire in loft.
then put a coax plug on it and join it one at a time to each of the others in the loft and you will have a sky picture.


sky12042 - 26/2/13 at 06:52 PM

Connect cable at sky box to rf2. Turn on power in hidden menu. Services. 0. 0 1 select. 4.
Rf power supply on. Green button. Then go into loft and using a multimeter check for 9v at end. This will be your up feed.
Connect this to each cable and tune tv into ch68 on analogue. When you get a picture. Bobs your uncle.

Andy


Barkalarr - 26/2/13 at 08:14 PM

quote:
Originally posted by sky12042
Connect cable at sky box to rf2. Turn on power in hidden menu. Services. 0. 0 1 select. 4.
Rf power supply on. Green button. Then go into loft and using a multimeter check for 9v at end. This will be your up feed.
Connect this to each cable and tune tv into ch68 on analogue. When you get a picture. Bobs your uncle.

Andy


Ahaa - 9v is the key
Thank you my friend - clearly you are / were a sky engineer in a previous life. Nice tip