Coax Cable TV Differences

Lars-irl

Hi Guys,

We currently have NTL in my house and im trying to move the TV point from one room to another.

The current signal is digital as goes into the NTL Digital box Set top box and into the T.V. The plan was just to extend the cable by 5 meters and feed it into the other room through a whole in the wall

Now my question arises around which type of cable I need to extend the feed. The guy in Power city pointed us to Satellite cable which he says every1 uses now. I bought and tried the cable and no joy. Thinking the cable was to big I tried a small section of the cable and it still didn't work. I had a small piece of standard old coax cable and hey presto it worked.

My question is what cable do I need to buy to extend by 5meters? Also what's the difference between the satellite cable and standard coax? Both just look like coax to me, but the satellite cable didn't work.

thx.

DublinDilbert

Lars-irl wrote: »

Hi Guys,

We currently have NTL in my house and im trying to move the TV point from one room to another.

The current signal is digital as goes into the NTL Digital box Set top box and into the T.V. The plan was just to extend the cable by 5 meters and feed it into the other room through a whole in the wall

Now my question arises around which type of cable I need to extend the feed. The guy in Power city pointed us to Satellite cable which he says every1 uses now. I bought and tried the cable and no joy. Thinking the cable was to big I tried a small section of the cable and it still didn't work. I had a small piece of standard old coax cable and hey presto it worked.

My question is what cable do I need to buy to extend by 5meters? Also what's the difference between the satellite cable and standard coax? Both just look like coax to me, but the satellite cable didn't work.

thx.

Ummm it should work... are you sure you didn't have a short between the screen ( foil or copper ) and the centre conductor.... i'd imagine satellite cable should work well...

Lars-irl

DublinDilbert wrote: »

Ummm it should work... are you sure you didn't have a short between the screen ( foil or copper ) and the centre conductor.... i'd imagine satellite cable should work well...

No, no short. I tried a small section of satellite cable about 6 inches and was very carefull no foil, or shield was touching the copper cable. That didn't work either...I got a 6mtr 75ohm cable of coax and that worked perfect.

Just weird that the satellite didn't work at all.

northdublin

is there a name or lettering/numbers on the sat cable, sounds like they sold you the wrong cable and are you using f type connectors or the old rf type?

Steve

There is a difference in the reactance between satellite cable and ordinary VHF cable, beyond that I'm lost though.

I'm surprised it didn't work with the short piece though.

The demodulator in the wall socket normally has separate cable and FM outputs, the digital box won't work with the FM one so check again where you plugged it in.

lucernarian

Could you check with a multimeter to see if there's a short between the outer shield wires and the central solid wire?

There should be a setting where the multimeter buzzes when the probes tip or there is a short circuit. If not, set it to Resistance anyway and put one probe on the central wire and the other probe on the shield wiring. Make sure the probes don't touch each other. If the reading is near zero, then the cable ends have inner and outer wires touching each other or cable is faulty.

But yeah, satellite cable is the best stuff to use. All coax cables you'll get in the usual high street places will be 75 ohm. You'll only get other impedances in trade or speciality shops.

I can get a UHF TV signal to pass through 12 inches of 2.5mm mains wiring, but the results aren't fantastic:pac: