Cat5 degraded video

[zuki79]

Yallo, just installed a pair of 1200tvl floureon cameras under the eves using Cat5/ baluns

testing the cameras before i fitted them, quality was super clear...but when i have fitted them the video looks quite grainy

the cable length is only about 15ft runs to the dvr, which lives in the loft

The DVR is set on 960h, would it be better on D1?

power to the cameras is sent via 12v 5amp power supply with a 1 - 4 (camera power) plug things - if that makes sense


this is my first install...if you hadnt have guessed

 

[sparkymarka]

Rubbish cat5 or baluns ? How did you test them before install ? Direct to a monitor / tv ?

 

[zuki79]

Yallo, will find the spec of the cable tonight

Baluns were from eBay - so quality unknown

test was basically as is the install, length of cat5 to cameras to dvr - just the length of cable was different - if that makes sense

 

[sparkymarka]

Ccs ? Copper coated steel cable ?

 

[Sally2000]

960h has the same number of horizontal lines as D1 but a wider screen, so it's preferable to set the DVR to that resolution.
But you need to set the cameras to the same output resolution. If they are different then the DVR has to do some conversion which will not produce the optimum quality.

If your loft gets very hot in summer then the little fan/s fitted to the DVR may not be enough to cool it. I leave the lid off the DVR and fix a large computer fan over the top to direct cooling air down over the circuit board and hard disk.

 

[sparkymarka]

what ! What Dvr do you have ... You should not have to do that !

 

[bernardgreen]

A "domestic" DVR is not expected to survive in ambient air higher than 25°C, many will but their life span may be reduced. Industrial DVR should survive at 25°C and higher. Read the specification's ambient temperature limits when choosing the DVR and its location.

If it has to be in a loft then keep it as low as possible ( hot air rises ) and if blown air cooling is needed then blow the air from a low level where it will be a bit cooler.

 

[Sally2000]

My DVR is on the floor in the loft and the ambient temperature there has been as high as 40C. The heat sink on the CPU got too hot to touch.
It's a simple matter to connect a computer fan in place of the tiny standard one and direct its airflow down onto the board and disk.

 

[cajar]

From reading the question, it looks like he switched on the installation and straight away noticed it was poor quality, so doubtful that's it' an overheating issue.

Likewise, the resolution would be the same as when he tested the equipment before installation.

 

[bernardgreen]

just the length of cable was different - if that makes sense

If the CAT5 is poor quality cable using copper plated steel then the loss of picture quality might be due the cable. The steel of one core of a pair acting as a magnetic core the other wire of the pair. ( they are twisted around each other ). This magnetic core effect would affect the signal quality.

 

[AlanE]

Probably more common than steel is CCA (Copper Clad Aluminium) and even the manufacturers of this cable recommend it is not used on CCTV because it degrades video quality.

 

[Sally2000]

so doubtful that's it' an overheating issue.

I wasn't suggesting it was, only that the OP mentioned it was in the loft and I was giving some advice that it will get very hot there in summer.

Incidentally OP why don't you just use coax rather than use CAT5 and modems? It's very cheap and avoids issues like this.

 

[EightyTwo]

Incidentally OP why don't you just use coax rather than use CAT5 and modems? It's very cheap and avoids issues like this.

That made me think...

Are you using some of the CAT5 for powering the cameras? If so, is your 5A PSU a switch mode power supply (no great big transformer inside)? If so, the PSU could be generating interference. Try running the camera from a battery and see if the picture improves.

If it is the PSU, swap it for a linear one or run the cameras from 24VAC with a suitable tramsformer/PSU (but you can't battery-back an AC supply without buying an UPS).

The NVT baluns are really good...

 

[zuki79]

cheers for the replies...

i used Cat5 as i work in IT so have bulk spools of it

i was using one pair for video and another pair for the power (an snipping the rest off)

i will order ready made coax cables (shotgun?) an hopefully that will improve things

regarding the temperature issues, i hadn't thought of that to be honest, i have water coolers for PCs so if things got really bad could try one of them.

thanks

 

[bernardgreen]

regarding the temperature issues, i hadn't thought of that to be honest, i have water coolers for PCs so if things got really bad could try one of them.

A vent in the soffit and a fan importing external air into the loft and onto the equipment has been found to be effective. Ensure rain cannot enter the vent. Also helps to reduce other heat related problems in the loft.