Maximum Distance For A Rg59 Cable

[scott5566uk]

Hello , I have recently installed in colour bullet camera over a distance of 130 mtrs, the camera only shows black and white. The picture is clear , is this because of the distance that I have lost the colour aspect. Can anyone recommend a video booster ? .

Thanks in Advance

[PJF]

I doubt its your cable mate, have you bench tested it next to your controls & did you still have a mono image. Have you checked all the settings on your control are set correctly. Whats it connected to ?.

[whistle]

I doubt its your cable mate, have you bench tested it next to your controls & did you still have a mono image. Have you checked all the settings on your control are set correctly. Whats it connected to ?.

AGREED

[ian.cant]

Rg59 should be good for way over 300mtrs, it is more than likely your camera!

[Guest prescott2000]

Rg59 should be good for way over 300mtrs, it is more than likely your camera!

Totally agree, i,ve run rg59 lots further thsn that and even had telemtry no probs. Check your not on a mono monitor

[Guest]

Totally agree, i,ve run rg59 lots further thsn that and even had telemtry no probs. Check your not on a mono monitor

QFA. 500m and no prob. And that was in relatively "bad" conditions..

[SystemQ]

Hi.

You probably have a mixture of three things here:

1- The cable run is long, but by no means excessive.

2- A weak video (colour) signal coming out of your camera.

3- A monitor that is not very sensitive to the colour burst of the video signal

I

[Matt the Teckie]

Just out of interest... what's the environment to which you're applying the RG59? Is it going outside, adjacent to power cables, underground?

One of the fundamentals of Coaxial cable is that it's not just resistive, it's also reactive. The overall capacitance (and therefore impedance) of the cable changes at various lengths. This means that the cable will more or less resistant dependant on the frequency. A composite video signal is made up of a few different frequencies all sat on a carrier of 50Hz. The colour burst information runs at around 5MHz at an amplitude of around 300mV p-p.

If we assume that the video signal can afford to lose, at the very most, around 6dB before you start seeing serious degradation, we can work out the theoretical effects of your video run.

General purpose RG59 has an approximate attenuation of around 2.25dB per 100m. Now over 130m, we can estimate that there should be a video signal loss of about 4dB (incl 2x BNC links at 0.5dB each). So you've already consumed two-thirds of your signal's acceptable loss.

Now remember, these are best case estimates under ideal environmental conditions and anecdotal evidence can swing either way. Depending on the answers to the questions originally posed in this post, the outcome can vary a lot.

My advice would be to run application suitable CAT5 and use (decent) passive video baluns (around

[esp-protocol]

Matt that sounds great, and I assume you are saying that generally you won't get colour signals back over 300m of RG59 due to the losses?

But Georgahti and others are saying 500m and no problems.

So if i had to install co-ax to a camera and my mother in laws life depended on a crystal clear colour picture, what is the longest length of cable I could safely install ??

[Matt the Teckie]

Matt that sounds great, and I assume you are saying that generally you won't get colour signals back over 300m of RG59 due to the losses?

Yup. The colour burst (being generally the higher frequency) is the first to suffer to the attenuation factors of the cable. Analogue systems used to reproduce the picture (CRT monitors etc) tend to produce better results. Digital systems (DVRs, IP Encoders etc) tend to have a definitive thresholds with regard to video levels and are generally far less forgiving.

But Georgahti and others are saying 500m and no problems.

Quite right, which brings us back to the environmental factors and the questions posed at the beginning of the post. I've don't doubt those who quote larger distances in the slightest but it certainly isn't a rule and some have degradation issues at much shorter distances too.

So if i had to install co-ax to a camera and my mother in laws life depended on a crystal clear colour picture, what is the longest length of cable I could safely install ??

If it was my mother-in-law, about 20,000m. Yours, no further than 150-160m. If you need to go further than this, I'd suggest using fiber (60Km), CAT5(1000m) or microwave(+1000m).... if you want be 100% sure.