CCTV at farm gate

Wazrus · Aug 13, 2012

I'm in the process of fixing up my driveway/road - the LED lights for which I've sorted out, thanks to Tractor By Net, but the gate TV is giving problems.
I have a 100m (330ft) RG6 co-ax cable run and my 'setup' doesn't seem to like a run quite as long. Everything works well (camera, monitor, cabling) with short runs, but when I hook in the 100m RG6 co-ax, I get a 'no signal' message on the monitor. I have a CATV amplifier, which I've tried at both ends of the cable run, for another 'no signal' message I've checked the co-ax for continuity and it's OK., as are all the other connections. Connections are all crimped BNC, using the proper cable crimping tools.
The camera is a Samsung SDN500. The amplifier is a 'Seebest' (Chinese) "CATV signal amplifier" (quote), which could conceivably be entirely the wrong 'thing'. I'm no electronics 'type'!!
Perhaps I'm on the limits of a 'wired' setup?? It seems to me though, that there are runs far longer than mine, i.e., in apartment blocks, or do they prefer wireless? Maybe wireless is the way to go, but from my (very) limited experience, 'wired' is preferable. Any thoughts from the membership???
Thanks
Wazrus Australia

KTurner · Aug 13, 2012

100m should be fine for RG6. Does the setup work when using the amplifier with the short run of cable? Did you check the coax for resistance between the center conductor and shield? With nothing hooked to the other end, this should be open. Is this a new setup or has this worked in the past with the same cable? Do you have any splitters or does your amp have more than one output? If yes, put a terminator on any unused outputs.

Keith

MikeInEburg · Aug 13, 2012

A standard CCTV camera produces baseband video. A CATV amplifier is used for modulated video. They are incompatible.

That said, a camera should work fine on 100 meters of coax without amplification. How are you powering the camera? 100 meters of 16 or 18 AWG between camera and power supply would definitely be a problem.

stingray1 · Aug 13, 2012

I'am with Mike I feel the problem is probably with the wire size and/or the power supply. The coax should be o.k.

Wazrus · Aug 14, 2012

Keith and Mike and Stingray

Thanks for taking the trouble, chaps

The power supply for the camera will be close by - i.e, about 5 feet away, (I have mains 240v power at the gate) so I don't think there's a problem with any losses due to cable run. My 'test' - before pulling the coax through the conduit - was to lay out 100m of coax on the ground, camera one end, monitor the other and all I had was the dreaded 'no signal'. Camera power was about 5 feet away.
The short run of cable worked just fine: clear, steady picture. Power again 5 feet away from camera.
The pundits here in Australia came down 50-50 as to whether there'd be problems with the 100m run, so I installed the amplifier - the wrong one ( thanks, Mike) - but with or without it, still there was 'no signal'.
If you all don't mind, I'll keep you posted with my bumbling around, and I will check the resistance as suggested. I will also lay out the coax in a straight line, instead of an 'out-and-back' loop and I'll also chop off the BNC connectors and do 'em again.
The whole thing is part of an exercise to remote power my gate, install LED lighting on the road and generally spiff up the front entrance. By the way, there'll also be another TV camera, but it'll be one of those bollard-mounted video doorphones, or something similar. (Hard to a doorphone for outside use) You really don't want to know what the 'experts' wanted to charge for the whole show: it certainly makes the bumbling about worthwhile and thus this thread.
Thanks once again for your input(s), Tractor-By-Net is the goods!
Wazrus Australia

Wazrus · Aug 14, 2012

Hard to FIND a video doorphone for outside use. Left out 'FIND' didn't I?
Wazrus Australia

Wazrus · Sep 1, 2012

Mike, Keith and Stingray
G'day from the other end! I mentioned I'd keep you posted with my bumbling with the CCTV and it seems I'm over the 'no signal' hurdle. Having changed all the connections to compression type and with the (absolutely) correct compression tools, the dreaded 'no signal' re-appeared.
At a loss as to exactly what to do next, I took the last resort and that was to lay the RG6 out 'straight', i.e., no 'loops', hook it all up - again - and bingo! Clear, steady picture.
When I mentioned 'loops', they weren't in just a jumble of cable on the ground, but a fairly carefully set up 'out and back', 50m cable out to the gate, 50m back, with just one return loop, no joints. Possibly, too, there might have been some interference from underground (1m down) power cables which were crossed twice. However, your guess is as good as mine: perhaps there's some pratical explanation, but it all seems to me to be a bit strange.
Anyway, thanks again for your input(s)
Wazrus

What's the difference if the cable's out straight or looped 'out and back'??

MikeInEburg · Sep 1, 2012

I'm not sure that I understand... What is carried on the "out" segment? I would think you would have camera to coax to monitor - requiring only one segment of coax.

k0ua · Sep 1, 2012

Wazrus said:
Mike, Keith and Stingray
G'day from the other end! I mentioned I'd keep you posted with my bumbling with the CCTV and it seems I'm over the 'no signal' hurdle. Having changed all the connections to compression type and with the (absolutely) correct compression tools, the dreaded 'no signal' re-appeared.
At a loss as to exactly what to do next, I took the last resort and that was to lay the RG6 out 'straight', i.e., no 'loops', hook it all up - again - and bingo! Clear, steady picture.
When I mentioned 'loops', they weren't in just a jumble of cable on the ground, but a fairly carefully set up 'out and back', 50m cable out to the gate, 50m back, with just one return loop, no joints. Possibly, too, there might have been some interference from underground (1m down) power cables which were crossed twice. However, your guess is as good as mine: perhaps there's some pratical explanation, but it all seems to me to be a bit strange.
Anyway, thanks again for your input(s)
Wazrus

What's the difference if the cable's out straight or looped 'out and back'??

There isn't any difference.. and the underground power cable should not matter either. This is coax we are talking about here. No in my estimate you have a defective piece of coax. with an intermittent break in it. When you move it around, you make and break the continuity. It is either still the connectors, or the coax itself is broken in the middle somewhere. That is all I can think of. If some of them time the signal is great, thru this coax and some of the time it is not, then the coax connection is intermittent.

James K0UA

joshuabardwell · Sep 1, 2012

k0ua said:
There isn't any difference.. and the underground power cable should not matter either. This is coax we are talking about here.

Right. The whole point of coax is that the conductor is electrically shielded from the outside. Coax is very resistant to electrical interference. Either the run is too long and signal from the camera is too weak, or you have bad connectors or a bad run of cable. Given that you re-crimped the connectors, it's probably the cable--as silly as that sounds, I know, because what could go wrong inside a spool of cable?

Have you tried testing continuity through the cable? If you do this, do it while a helper wiggles and jiggles the cable all along its length. See if the continuity is interrupted at any point.

But, frankly, given the cost, I might consider just buying another run of RG6. If it fixes the problem, great, and if not, well, you'll probably use it somewhere, and at least now you know the problem isn't the cable.