Help for 2 Basic Questions

[Willie 0]

I am at the beginning of my first CCTV project. Please help me understand very fundamental aspects of CCTV, and forgive me for asking such basic questions (I have spent a couple of hours trying to find answers to these questions on the Internet and in the FAQ section of this Forum without success).

 

I have had a security gate installed at the end of my driveway. The gate includes a keypad for entry of a code to open the gate. The keypad is made by Chamberlain and is called the “EL25â€

[jisaac 0]

How far exactly is it from your camera to your monitor?

Instead of trying to figure out the bandwith and making it harder on yourself than it actually is just tell us the length and unless it is a long way you should be ok. In the instance it is to long then you can use an amplifier.

oh ya and the second question. yes you can plug it into your dell monitor. Now the question is will you pleased? Most likely not. Most people prefer the crt's. I could try to explain it to you but the best thing I could say is it just looks funny.

[Willie 0]

I'm sorry I didn't make it clear in my first post. The distance from the entry of my house to my monitor is about 35 feet. So, the total distance from the camera to the monitor is about 1,110 feet.

 

I guess the reason I like to make things hard for myself is that I like to dig into a subject and try to understand it, instead of just blindly following the manufacturer's instructions.

 

If I simply use a video amp and use the suggested RG59/U cable, the amp can only amplify the signal it is given. If the higher frequencies of the video signal are attenuated, compared to the RG6/U, they are going to be amplified but will still be lower than the lower frequencies. Won't this result in a reduction in the resolution and the finer detail of the image?

 

I'm sorry to hear I won't like the image I see on my monitor. Can you tell me what the problem is and how it would look different from a CRT monitor? Is there a way I can get around this problem?

 

Thanks for your help.

 

Willie

[jisaac 0]

 

I guess the reason I like to make things hard for myself is that I like to dig into a subject and try to understand it, instead of just blindly following the manufacturer's instructions.

thats good. Shoot I wish alot of the people I get calls from to do proposals would do the same thing. That way they have some clue as to why you need the things I suggest.

And you wont get burned. Like alot do.

 

 

I'm sorry to hear I won't like the image I see on my monitor. Can you tell me what the problem is and how it would look different from a CRT monitor? Is there a way I can get around this problem?

 

Thanks for your help.

 

Willie

 

now I did not say you wont like it. I said most likely not. I am just basing that off of 99% of the people who do that. For all I know that may be great for you. But in most scenarios it is not pleasing. I did the same thing and use little crt's for my system now.

Anyways if you want to use rg-6 go ahead. Just be sure to use the copper shielding instead of the aluminum. You could also use cat 5 cable and a passive and active balun to get the video back. Much less bulky.

[AVCONSULTING 0]

You will certainly need an amplifier and the Pelco equalizing amplifier would be the best if you are going to use coax. You must use coaxial cable with copper braid and copper core. Do not use any coax that has aluminum or you will get a terrible signal even with an amplifier.

 

Using twisted pair and converters would be the best. Here are some links to some information.

 

http://www.pelco.com/products/en/contents/pelco%20ea2010%20equalizing%20amplifier_spec.pdf

 

http://www.nvt.com/index.html

[rory 0]

Just get some RG59 Siamese Cable .. 35 feet is a breeze .. no need for amplifiers at that distance .. now if you already have twisted pair running to the gate use that, but get some decent RX and TXs for it .. quality typically isnt as good as RG59 unless you use amplified though for longer distances .. but 35 feet should be as good.

 

LCDs are just not as good quality as a CRT in any application, its the technology is all. And if it is a composite signal (CCTV-Bnc/RCA) it is 5-10 times worst quality .. CCTV CRT monitors are the highest quality for CCTV cameras .. but ofcourse more bulky ..

 

Anyway I think JIssac summed it up ..

[Willie 0]

Thanks to all of you for the helpful information.

 

Rory, I don't have any cable installed yet. The purpose for this post was to decide between RG6/U and RG59/U.

 

The RG-6/U I had in mind from Belden uses a solid copper core center conductor, but it does have a shield that includes an aluminum foil as part of its 100% shield. Looks like I need to keep searching for better coax or turn to CAT 5 cable.

 

The Pelco Video Amplifier/Equalizer seems ideal for this situation. It appears to allow me to adjust the amount of gain both below 12 MHz and above. This will allow me to have a much flatter frequency response. But, that leads me back to my original question: what is the bandwidth (i.e., how high is the highest frequency) for the video camera I have bought (as described in my first post of this string). I probably gave too much detail in initial post, so I am going to try another post with my question asked more simply.

[rory 0]

Like i said .. 35 feet .. all you need is RG59 Siamese .. you can buy this from any electrical store. (copper solid center and copper shield)

[AVCONSULTING 0]

Rory, the distance is over 1000' from the gate back to the monitor. I do agree that twisted pair is the best. Again, never use aluminum, it is not designed for CCTV. I doubt if you will find detailed spec's on the camera since those are usually low cost Taiwanese cameras and have almost no

engineering specifications.

[rory 0]

ok .. he lost me here though ..

 

"The distance from the entry of my house to my monitor is about 35 feet. So, the total distance from the camera to the monitor is about 1,110 feet"

 

if its over 1000', best he go with active NVT then ..

Edited June 24, 2006 by Guest

[jisaac 0]

ya especially if you are going that distance go with cat 5e. Get some QUALITY video baluns. One active and one passive. NVT sells some good ones. Just do not go with the cheap ones as their is a big difference. Even in the passive ones. By using cat 5 you can maintain quality images over long runs.

 

I had a instance here recently where I had a ground loop problem and so I threw a cheap active transciever that i have had for like a year and a half at the dvr location. Well it did solve the ground loop but I was not able to get my iris reading below 120 IRE's. Which made the dvr read above its threshold and made the dang thing power cycle on and off alll night! So get the good ones

[jmason 0]

You won't have any bandwidth issues period. All securty cameras operate in the same "baseband" Range. An amplifier or active transceiver as sated by others above will over come you distance issues. Most coax cable is swept from the factory up to 1Ghz. Your local cable compant bearly uses that much space on their entire system. You will have no bandwidth issues for the camera you are using or any other for that matter. Hopefully this sheds some light. CCTV transmitts at very low frequencies the lower the frequency the less attenuation you have. You are well below any frequecy that would make "tilt" type attenuation happen. Use an amp or an active transceiver, and all will be well

[Cooperman 0]

In answer to your original question Willie, as the bandwidth is somewhere around the 5MHz ish figure, that would be the attenuation figure that an engineer would look at if trying to calculate the signal loss.

 

That said, whilst you could use a decent quality RG 6 / RG 11 / CT 100 type coaxial cable over that distance, RG 59B/U would require a launch amplifier, and as the other guys have already suggested, you may well be better off in any case, using UTP with an active balun component.

 

Incidentally, if it was a monochrome camera, you could probably have got away with using RG 59B/U but with some slight image degredation. Over that distance there wouldn't be any chrominance signal left at the back end.