DVR output using CAT5

[third eye security 0]

Hi guys, i am seeking some advise if possible. I have installed a 16ch DVR system. I have a monitor connected locally to the DVR but the site has a TV about 150m away. I have run a CAT5 cable and connected Baluns at each end. The problem im having is that the image on the TV is not stable. It flickers on and off and the picture quality is very very poor. On the TV side using a Balun i tried connected via bnc to scart, bnc to phono and cat5 to vga. All with the same results.

 

I tried using 1 pair, 2 pair, 3 pair and 4 pair same result.

 

I have tried replacing the baluns, same result.

 

on the dvr side, if i plug 1 camera directly in the balun i get the 1 camera image on the TV. which indicates that the cable is fine. If i use a T BNC connector to split 1 camera feed i get the same problem as when connected to the video out for the DVR.

 

So it seems when going via the DVR the picture gets distort. I am pulling my hair out now and i cant think what else it could be.

 

Guys any help would be much appreciated.

 

Thanking you in advance

[SDM Group 0]

Check the termination on the DVR settings

[Birdman Adam 0]

What output on the DVR are you feeding into the balun? Just a BNC spot output?

 

Are your connections on the baluns the same on each end? For example, white/blue on the left terminal, blue on the right at the DVR, and same at the TV. If you mix them up it works, but the picture is crap, like what you are describing.

 

What inputs are you putting this signal into on the TV? It should be a composite input.

[third eye security 0]

The DVR only has 1 bnc output which it is connected to.

 

yes baluns at both ends have the same colours going in to the same side left of the balun all strips right all colour.

 

i have tried the scart input, vga input using a cat5 to vga converter and composite input the yellow 1. all have the same results.

 

im running out of ideas on this...

[third eye security 0]

SDM Group - not sure what you mean by check the termination on the DVR?

 

can you change the output setting on the dvr?

[SDM Group 0]

The DVR should have a software option or dip switch to change its state from terminated to unterminated or vice versa.

[Horizon 0]

Hi third-eye.

I've no practical long distance experience with baluns and CAT-5, but from a theoretical point of view...

(Oops, it's going to be wordy.)

 

First up you don't want to parallel up the twisted pairs in the CAT-5, you'll want to use only one twisted-pair, such as blue and blue/white. The reason for this is that it will cause an imedance mis-match through the balun, and part of the signal will reflect back and forth at the baluns - the signal will be distorted.

As birdman says, they need to be connected the same way at each balun. It must be one pair - not parts of different pairs (like using orange and blue). You need the twisting for the impedance, and protection from interference.

 

The local monitor at the DVR should be either disconnected, or set to unterminated, or high impedance (Hi-Z). If it isn't you'll have the wrong impedance there, and get reflections. Probably easier to leave it disconnected, and plug the balun right onto the spot out terminal.

 

At the other end of the CAT-5, go through the balun, then straight into the composite video (yellow connector) on the TV.

 

So hopefully you have:

  DVR --------------> Balun -----------------------------------> Balun ---------------> TV
75ohm out        75 to 100 ohm      150m of 100ohm CAT-5      100 to 75ohm             75ohm
                                       (one pair) 

The TVs always have a 75 ohm input for the composite video.

 

Err, good luck?

Cheers

[gungate 0]

I have not tried this but try a active balum and a passive balum and yes do use only pair.

[Blake CCTV 3]

gungate has a good idea try using an active balun the best type are the ones with variable pots they give a more precise adjustment than the ones with dip switches.

If you have an oscilloscope you can check the video signal coming from the camera and at each point along the signal path eg. at the camera output, DVR input, DVR monitor output, the remote monitor input.

you are looking for 1v of video signal at each point.

 

Something simple that you can try is to bring the remote TV locally to the DVR and connect it using a short piece of cat 5 cable and your baluns.

This will elimnate the long cable run (which isn't that long for cat 5) and earth loop faults.

 

what is your location

[vincenttor 0]

what also helps is a FTP cable or Sftp

 

i have had some problems also with cheap cat 5e cables then i tried another cable and suddenly 5 times sharper image and no more problems

or maybe you are using a cable like that allready

 

the thing i discovered when measuring with a multi meter/volt meter with the cheap cable

when i measured 1 pair it said 130 Ohm then i grabbed the orange/orange white pair and it had 30 ohm resistance.

 

all the strings gave different value's and had big problems transferring video/rs485 signal

then i bought a Ftp cat5 cable and all the value's were the same 25 Ohm if im correct .

after connecting it i noticed that the image was much more sharp then before and i could even power the camera trough the cable by using 2 pairs for + and - on a distance of 55 meter

 

(the cheap cable worked perfect with a lengt of 5 meter, so testing like that would not help you)

 

good luck

[joseph.chen0312 0]

Dear All,

 

I think there are two possible reason caused that, first I agree with yoru point is qulaity for Balun and cable because not all items couls sustain delivery steady signal to 150m, if you take cheap one you will fail for signal attenuation highly.

 

Another you may be could check what is the system in DVR PAL or NTSC, you knwo it total different frequency.

[CCTV_Tech 0]

Hi guys, i am seeking some advise if possible. I have installed a 16ch DVR system. I have a monitor connected locally to the DVR but the site has a TV about 150m away. I have run a CAT5 cable and connected Baluns at each end. The problem im having is that the image on the TV is not stable. It flickers on and off and the picture quality is very very poor. On the TV side using a Balun i tried connected via bnc to scart, bnc to phono and cat5 to vga. All with the same results.

 

I tried using 1 pair, 2 pair, 3 pair and 4 pair same result.

 

I have tried replacing the baluns, same result.

 

on the dvr side, if i plug 1 camera directly in the balun i get the 1 camera image on the TV. which indicates that the cable is fine. If i use a T BNC connector to split 1 camera feed i get the same problem as when connected to the video out for the DVR.

 

So it seems when going via the DVR the picture gets distort. I am pulling my hair out now and i cant think what else it could be.

 

Guys any help would be much appreciated.

 

Thanking you in advance

 

My experience with LAN cabling tells me that CAT5 and a Balun simply will not work at that distance. There are some amplified video-senders like the Lynx Bobcat that can send composite upto 600 feet over cat5. www.lynxbroadband.com

[Blake CCTV 3]

Have you tried an isolation transformer between the DVR output and the remote monitor. Remember only use one pair of the cat 5. What is your location?