the toss

You will need to look at the camera output when the problem is occuring to determine if it is a camera fault or a signal transmission problem. Go from there

CVI or tvi is not better in low light...if you compare 720p ip systems to 720p cvi, they will be more or less the same with respect to night vision and low light ..its just when you go to the higher mp cams that night visions suffers. Hd-cvi requires separate power runs which can be a pain and also requires a home run to the dvr..which can be alot of work on some install.. As far as robustness, i dont know what you are talking about...never had ethernet cable fail once its installed..With 720p ip systems running cheap, its silly to run coax in 2015..it simply makes no sense.. and if op "must" run coax then he should be looking at hd-cvi not the junk 960h systems that look like crap.. OP what is your budget and how many cameras are you installing? When you buy cat6 make sure you buy from a reliable well known seller and that the cable is NOT copper clad aluminum (CCA) rather solid (not stranded) copper cable. Monoprice is a good source. Then you are a very lucky person. A solid conductor UTP pair terminated to a balun floating around behind a DVR is a problem just waiting to happen which ,as I said, can be minimised by use of a panel mounted balun & patch lead

I have to agree with fertilebert. With IP cameras you really have no choice but to use UTP cable. The trouble is that many people don't give the full story - only what their preference is. Many people think that if you want HD then you go IP. When based on affordability HD-cvi & HD-tvi will generally outperform IP especially in poor light. They run on coax which is light years ahead with regards to robustness. Unless you use proper terminating techniques ( ie. a patch panel) then using UTP with baluns swinging around on the end of the pairs is just asking for trouble

The only problem that presents is one of health & safety. Use proper protective euipment and do it as you planned.

Not really. Intermittent problems are , by their very nature intermittent. Sometimes they are there , and sometimes not. They can be brought on by temperature changes , humidity changes , vibration or strain. They are always solved/avoided by good soldering techniques. I remember as an engineering trainee, a co worker had an excellent method for identifying intermittents. He would put a multimeter on it then pull/twist/strain the connection trying to bring in the fault. When it finally let go due to the abuse applied to it my co worker would interpretted it as definite proof the fault existed in the first place.

"WD" (wide dynamic ) has nothing to do with supply voltage.

Join the two +ve together & join the two -ve together.

No Don , it would normally cause major problems by using one twisted pair for each leg. I'm at a loss as to what is happening here

Seems like we are going around in circles

The short length of those pigtails isn't really going to have any any effect on the overall voltage drop. Yes you can multiple up the outputs & that should be mentioned in the power supply specs. The jagged outlines on your picture ( and the rainbow type colour patterns ) is a result of a low quality image sensor.

Most DVRs have HDMI . VGA & composite outputs

HD-TVI will have no problems over that distance. Your problem is that you really need 3 different voltages to supply your cameras. One supply simply wont do it unless you have 24Vac cameras. If you get a supply to run the closest cameras you only have 6v at the furthest cameras. If you get a supply to run the furthest cameras your closest cameras will have about 18V. You have no easy way out.

You are discovering all the things that should have been addressed in the planning stage. If the cameras are HD-SDI then your voltage drop may not be your only problem. Those longer cable runs are a fair bit beyond what is recommended for HD-SDI. If they are dual voltage cameras ( 12Vdc/24Vac) then yes the simplest way would be to run them at 24Vac.

The sensitivity setting will be different for every user & location. There is no "one setting suits all" and your will need to keep playing with it until your are happy.

Then why not just use a 24Vac camera as there is already one built into 24Vac cameras.

So I take time out of my life to not only give you the answer you seek but also explain the solution to you and for my efforts get labelled a condescending jerk. Your opening post seems more of a demand for an answer than a request for people to help. I think you have serious character flaws. I have re done my calculations & it seems I made a mistake. What you REALLY need is a 62.5Vdc power supply.

I have a multimeter, but I don't see how to use it if the contacts are not exposed while the cameras are connected. The real question is what is the solution. How do I get enough power to the cameras?? The REAL question is - do you want to understand your problem or do you just want somebody else to solve it for you? Given that the voltage drop is 4.12 volts (for the parameters you have given) then getting a power supply that provides 4.12 volts ABOVE the nominal 12V required by the camera will offset that voltage drop. So a 16Vdc power supply will solve your problem -for the specific camera in question

All things being equal the cat6 will give the better result simply because of its lower attenuation. If you find this is not the case then I would suspect the cat5 is copper & the cat6 is CCS or aluminium.

I have NOT said to disconnect the camera. The voltage reading must be done at the camera while it is connected & the IR is on. You should be able to buy a cheap multimeter for less than $20. A simple calculation using 12Vdc as your power supply , 460 mA as the current drain and 700' of 18 awg as your cable gives a voltage drop of 4.12V meaning load voltage is 7.88V. This is way below what you would expect the camera to run on.

HD-CVI & HD-TVI are both hi-res analogue systems that will run on your existing coax infrastructure and give comparable quality to IP without the associated problems. Yes you will need to replace the DVR & cameras but these are usually less costly than the IP equivelents.

You need to measure the voltage AT THE CAMERA at night with the IR operating. That will give you a clue as to what is going on.

Thanks for the help. I already tried swapping out the camera with one I know works and I replaced all the connectors (which didn't solve the problem), so it must be a short in the cable itself. The current cable is rg59 siamese direct burial (18/2 for power) and for there to be a short in the cable would mean that the cable came faulty from the manufacturer, which seems hard to believe, but possible. The cable run is 125 meters and I assume the only solution is to run another power cable just for that camera all the way back to the power supply (there isn't any power source closer). I once had a 500m box of 6 core security cable that was in two lengths joined with sticky tape at the 350m point. If my off-sider hadn't seen it as it was being pulled out it would've caused all sorts of problems.

The light off means NO power is being supplied to that output. This will be due to a current overload triggering the electronic fuse (PTC). Disconnect the camera on that feed but leave the cable connected to the power output at the power supply. If the light still goes out then you have a short on the cable to the camera. If it doesn't go out then you have a fault in the camera itself

If your MAIN consideration is low light performance then go for a black/white camera. The more you pay the better will be the results. Get one with a half inch sensor if you can.

Well that's going to have excellent regulation & noise immunity