found some good deals ......

I found a few good deals and they are in the mail:

1) Speco HT650PT10X High Resolution Motorized Dome Camera

2) Speco DVR4TL250 4 Channel DVR

Now a few questions please -- the DVR has BNC camera inputs but the instructions for the camera are a little more complex:


Connect the camera using the supplied terminal block:

A) Connect the control unit via the twisted, 2-conductor line (max length length 1200 meters) to the pin array 5 (RS485A) and 6 (RS485B). Connect all cameras in parallel to this 2 conductor control line.

B) Feed the video signal at contact 3 via a shielded cable to the video input of the following unit (eg, monitor, camera switcher, video splitter)

Connect the shield to contact 4.

C) 12V + to pin 1 and ground to pin 2.


Ok now ..... RS485 control signals interface at a terminal block on both the camera and DVR. What is the best twisted wire pair to use for this? Would one twisted pair of a Cat 5 cable work ok for 100 yards?

If Cat 5 cable is used for the RS485 control signals, can I transmit the video and "shield" down a second twisted pair in the same Cat 5 cable?

Could I ship 12 volts and ground down a third twisted pair in the same cable? If so, how far?

Last problem, the DVR has BNC connectors for video in. Would I just soldier a BNC connector on the video cable for connection at the DVR? What about impedance matching? Any problems to watch for? What am I missing?


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Well, based on your questions it would seem that they may be incompatible devices.

Good Luck!!

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If you are using twisted pair for the video you should also use video baluns.


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See Inline

you could use shielded Cat 5

You could do the video if you are using balun's but not shield or power

No, cat 5 is not large enough to supply power 300 feet, assuming you are running pan tilt motors and heater/blowers. Their are online calculators to figure out your wire size.

Use Video Baluns

Hope that helps, James

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James B

Excellent info -- thanks.

Who makes quality baluns? Any brands to avoid?

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I suggest you do a little research on what a "shield" is.

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Sorry, I did not think to mention what is meant by shield wire. The shield is the overall foil covering that would be around the cat 5 pairs. It is used to help keep out interferance. Along with the foil covering will be a wire with no insulation on it. This is the wire that is refered to when shield is mentioned.


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James B

Right. My post was aimed at the OP who asked about using a second twisted pair to transmit the video and "shield".

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Thanks folks.

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