video over existing phone line

[Al Drake 0]

I wonder if anyone here has done this and am thinking of giving it a try. I have an old home with existing unused phone line running to every room and wonder if I could use this line to carry video signal if I used balins and make an adaptor that just plugs right in. Right now I am using wireless 5.8 GHz transmitters/receivers but this might be an alternative. This just seems to simple so I am asking is there something I am missing or would this actually work? There is no connection to the outside and I have used this line for wired intercom and it works fine so no reason why I can't transmit camera signal to DVR or signal from DVR to external monitor for viewing in any room.

 

Al.

[Owain 0]

video signal requires significantly higher bandwidth and at a higher frequency than audio/phone/intercom.

 

Baluns also match to Cat5 cable, phone cable will have different twist ratio and different impedance so you will have an impedance mismatch.

 

But a couple of baluns are cheap enough if you want to try it.

[Al Drake 0]

video signal requires significantly higher bandwidth and at a higher frequency than audio/phone/intercom.

 

Baluns also match to Cat5 cable, phone cable will have different twist ratio and different impedance so you will have an impedance mismatch.

 

But a couple of baluns are cheap enough if you want to try it.

 

I have Baluns and have been assembling cat5 cables lately and thought phone line was more or less the same. It sure looks the same so I thought most any wires would work if there were baluns used for impedance matching. I have some pre-made cable I am using that looks like simple two conductor wire but it was made for CCTV. Not RG59 shielded and not cat5. It has BNC connectors on each end but I have never stripped it to see what it consisted of. I guess it must be the same impendence as RG59 but I am not sure. I don't see any baluns anywhere

[survtech 0]

CAT3 (Telco cable) can be used to transport video using baluns or active devices. The caveats are that the pair must be used for only video (no sharing with telephone or intercom) and that you can expect more interference on the line and in the video due to the reduced number of twists in the cable.

 

Also, the wire must be point-to-point. If your telephone line is wired in a "star" configuration (from a common point like in your garage to multiple rooms), you will likely get ghosts in the video. CCTV transport is not the same as audio. Unterminated lines cause major problems. You will have to find a way to get the cable straight from the camera to the DVR without any sidetracks.

 

By the way, both CAT3 (Telco) and CAT5 are 100-120 ohm cables and can be terminated with baluns. Baluns aren't that sensitive to impedance anyway. I've seen video transport on 18/2 and the picture looks OK. This is common in elevators.

[Al Drake 0]

CAT3 (Telco cable) can be used to transport video using baluns or active devices. The caveats are that the pair must be used for only video (no sharing with telephone or intercom) and that you can expect more interference on the line and in the video due to the reduced number of twists in the cable.

 

Also, the wire must be point-to-point. If your telephone line is wired in a "star" configuration (from a common point like in your garage to multiple rooms), you will likely get ghosts in the video. CCTV transport is not the same as audio. Unterminated lines cause major problems. You will have to find a way to get the cable straight from the camera to the DVR without any sidetracks.

 

By the way, both CAT3 (Telco) and CAT5 are 100-120 ohm cables and can be terminated with baluns. Baluns aren't that sensitive to impedance anyway. I've seen video transport on 18/2 and the picture looks OK. This is common in elevators.

 

Great. Thanks. I am not sure what condition or configuration the cable is actually in. I tested the connectivity by connecting my Vonage modem to one jack on the third floor and attached a phone to two different phone jacks on the first floor with success. There are a few jacks in different locations that show nothing so I will simply have to see what happens.

 

Al.