Pinout of TV antenna cable

[spleenharvester]

Trying to bring the antenna cable down from my roof to my living room, it's currently not wired to anything. But instead of a coax cable, I found two of these 4-core monstrosities. I'm guessing the two light green wires are common to eachother, as are the two dark green wires - and each 'pair' is either signal or shield. Any ideas?

[stj]

thats strange - was any coax with it?
old sattelite dishes had extra control cables.

[spleenharvester]

Originally Posted by stj

thats strange - was any coax with it?
old sattelite dishes had extra control cables.

The house has coax cables hanging out of the ceiling in various rooms (we just bought it) so they were clearly connected to the antenna somehow at some point, but they're not connected to anything now. So I'm not sure quite how they worked with it.

[petehall347]

control cable ..maybe for a rotator .

[redwire]

They might be balanced pairs, like 300Ω twin-lead but I'm not sure what the UK used for antenna feed-ins. One pair for one antenna i.e. VHF, the other for UHF.
There should be a balun or two on the roof.

[CapLeaker]

.

[CapLeaker]

Originally Posted by redwire

They might be balanced pairs, like 300Ω twin-lead but I'm not sure what the UK used for antenna feed-ins. One pair for one antenna i.e. VHF, the other for UHF.
There should be a balun or two on the roof.

The spacing isn’t right for 300 ohm twin lead. It almost looks more like a control cable for an old c-band dish to me. Or maybe an lnb with skew control? Or a 4 wire thermostat? Dunno.

[redwire]

It's got the the fat insulation on the conductors, solid wire- I've seen on some outdoor 300Ω cables.
Did they even use rotators in the UK? I've never seen it here for TV, only ham use. Satellite could use that cable for DC power but the signal still needs to come into the house somehow.

[eccerr0r]

I was thinking rotator wire too, and indeed they do make rotators for broadcast... so much that I thought hams decided to repurpose broadcast rotators for amateur use...

[stj]

the u.k. never used pairs for RF, always been coax.
a sattelite jack is unlikely, those use a screened feedback if done right.
a polariser is possible.
or could it have been power for a masthead amplifier??

[redwire]

Antenna rotators I worked with had a reversible AC motor, brake solenoid, and potentiometer for position feedback. So a few conductors required 3-5 flat 20awg outdoor ribbon cable was commonplace.
Masthead amp power is usually bias-T fed in the coax or two conductor DC power.
You wouldn't use solid copper because of the flex in the wind. It looks thick as if for a higher current load.
OP has got some martian cable.

[ChaosLegionnaire]

so what and where exactly was the other end of the cable connected to? i dont understand. it wasnt very clear in the first post and subsequent posts. so if both ends werent "wired to anything" like u said then the cable was just lying around or hanging around somewhere in the house. so where exactly in the house was it when u found it? and if the other end was connected to something, try to trace where the cable goes to then. it might offer some clue as to what it was for.

i just need to ask more questions about this and know more things about this light and dark green cabling before we really declare it "alien cabling" or "green martian cabling". or worse, get power and data/signal cables mixed up. mixing up power and signal cables is the fastest way to release the magic smoke from ic chips and stopping them from working anymore.

[petehall347]

looks like pairs of green and yellows to me .. not 2 shades of green

[redwire]

Maybe it's old BT Telephone Cable. What does rural telephone cable look like in the UK? I could find modern cable as a "single quad" but it's thin copper.

[stj]

not telephone,
wrong colours and phone cable uses 2 thin twisted pairs

one thing i noticed in that picture is the thick teflon looking insulation!

[CapLeaker]

Originally Posted by stj

not telephone,
wrong colours and phone cable uses 2 thin twisted pairs

one thing i noticed in that picture is the thick teflon looking insulation!

me too. Also why are there 2 identical wire pairs? It's not really twisted to be suited for phone. But then it doesn't matter if only one pair is used, because nothing is on the other pair to cross talk into.
I rather think it was a low voltage supply of some sort or a control cable. Small rotators don't have a brake. So a 4 wire cable would be a perfect fit.
The balanced twin lead idea is not right for me as the spacing is way too narrow to be 300 Ohm. What gives?

[redwire]

When I worked at an electronics distibutor, there was always odds and ends of the wrong cable someone had ordered, sitting in reels collecting dust.
There was cheapo customers that didn't care- "4 conductor" is all they wanted and we'd sell it cheap to get rid of it.

OP might just have some oddball cable that was cheap. Look for any writing on the jacket, it should have something there.

[spleenharvester]

Cheers everyone - still no idea what it is but I eventually found the right cable in the loft!