Max length of video run

[sjmaye 0]

Anyone know what the maximum length of run would be for a camera installation?

 

I am looking at runs between 200' - 600'. I had hoped to use the siamese coax with 18ga power leads. I was concerned about either video signal loss or voltage drop across the long runs.

 

Should I be worried?

[rory 0]

without looking it up, as far as I can remember, RG6 up to approx 1500-1800 feet, RG59 up to approx 1200 feet.

 

You will have video quality loss on any cable over a distance of 100'+, without using an amplifier. Shorter distances of a couple hundred feet or so you shouldnt notice it too much with RG59.

 

Power drops should not be an issue at a couple hundred feet or so, 300 feet or more you may want to power it at the camera or closer to it, seperately. Just depends on the location. Someone else can pan in on 18AWG distances perhaps.

 

Rory

[VST_Man 1]

voltage http://www.securityideas.com/securitycam/howtocalvold.html

video http://www.hometoys.com/htinews/dec96/articles/moses/catv.htm

[scottj 0]

Use 24VAC cameras for long distance installations. I personally prefer all 24VAC cameras whether the runs are short or long. Plus, the power supply cabinets are less expensive.

 

scottj

[Cooperman 0]

Just a couple of quick points on the video cable issue,

 

The improvement on signal attenuation (if you like, how much it degrades the video signal with distance), is not hugely better with RG 6 than RG 59B/U.

RG 11 is almost twice as efficient as RG 59, and so in general terms, you can run roughly twice the distance to achieve the same degree of degredation.

 

If monochrome cameras are being used, the furthest run I've ever tested was about 1500' on RG 59B/U and the attenuation certainly produced significant degredation in the received signal. The picture was more than adequate for the clients purposes, but overall it was a very 'soft' image.

 

It is important to remember that as a cable run gets longer, it is the chrominance (colour) portion of the signal which is lost, long before the luminance (monochrome) begins to degrade.

 

Generally, most manufacturers will rate RG 59B/U as ideal for both colour and mono cameras up to around 200 metres (600+ feet). Mind you, there can be quite a varience in quality between cables sourced from different manufacturers, so any rough guide has to be taken as such until tested in the field.

[DataAve 0]

I think that footage thing is just a gauge, because I have ran it a lot longer distances than recommended. Sometimes, you don't have a viable choice $$$.

[Cooperman 0]

I wouldn't disagree with that DataAve

[CSG 0]

This webpage bases its voltage loss on .5 amp cameras. All of the camera's i've seen use less than .2 amp. So under 1000' I dont think you have a problem

 

http://www.securityideas.com/securitycam/howtocalvold.html

[sjmaye 0]

This webpage bases its voltage loss on .5 amp cameras. All of the camera's i've seen use less than .2 amp. So under 1000' I dont think you have a problem

 

Based on .2A w/18AWG wire I get a dvoltage drop of about 2.54volts lost per 1000 ft. Can a 12v camera run OK on about 9.5 volts?

 

What is the rule of thumb for recommended voltage range for a 12v camera?

[rory 0]

Depends on the camera, and what power supply you are using. A Multi output supply can also come with anjustments. If you have the specs on the camera post them here. Normally though a 12v camera will require 12v. Some box cameras will say that it can take variables, but then they cost more.

[CSG 0]

Rory,

 

I would expect a top notch power supply (Altronix/Pelco) to have pottable outputs for each camera, that way one could adjust the voltage going to each camera, tweak it in to exactly 12v or 24v accordingly.

 

However I haven't been able to find this feature. The only thing I see from Pelco are 24v/28v output terminals.

 

Do any power supplies have adjustable outputs?

[rory 0]

you'd think right

 

They only have the adjustment from 12VDC to 24VDC from the ones ive used. They may have a model that has the other adjustments also, havent looked lately.

[scottj 0]

B-Tron power supplies, or Preferred Power brand. Same quality as the Altronix and Pelco (actually more headroom), and a fraction of the cost. Just a plug for some friends that work in the power industry.

 

scottj