Subscriber Discussion

Split An Analog NTSC CCTV Camera Signal To Feed Both An Encoder And An Existing CCTV Matrix

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Greg Hussey
May 11, 2016

Has anyone found a cost effective way to split an analog NTSC CCTV camera signal to feed both an encoder and an existing CCTV matrix. We have a situation where we have a large quantity of DVRs that supported looping outputs that now feed a large CCTV matrix. The cable is all there. Customer needs to replace DVRs with encoders. Has anyone found a product to do this passively without effecting signal strength/quality? Has anyone found a small/neat way of doing this with DAs? We can't re-wire everything to matrix and expand the matrix to support looping outputs to the new encoders. Existing matrix supports serial integration with PLC, we can remove matrix.

UM
Undisclosed Manufacturer #1
May 11, 2016

1) Choose an encoder with a looping output (I know, these are getting harder to find)

2) How far are the cable runs? Are you doing any Up The Coax control? If the runs are fairly short and you are not using up the coax control, use a splitter

or a large amp, such as this 16 in, 32 out:

http://www.cctvcamerapros.com/CCTV-Video-Distribution-Amplifier-p/amp-1632.htm

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Greg Hussey
May 11, 2016

The passive splitter has been considered in past projects but we have had issues with a DVR or encoder not seeing 1 volt peak to peak. Has anyone else used these with an encoder successfully?

SG
Stephen Godfrey
May 11, 2016

Greg,

Splitting an analog CCTV signal is a big no-no. You must maintain the 75 ohm impedance for proper signal and termination. A distribution amp is the proper way to accomplish this task.

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UI
Undisclosed Integrator #2
May 11, 2016

Check to see if the encoder supports switchable termination or possibly the matrix. Some have allowed it in the past. It's better to loop but it would maintain proper termination.

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Carter Maslan
Oct 07, 2016
Camio

Greg - did you find a solution?

We have the same need to encode the analog CCTV input without disturbing its connection to the DVR.

We're thinking of using https://www.amazon.com/gp/product/B00VG631NU

U
Undisclosed #3
Oct 08, 2016
IPVMU Certified

Does the dvr have a little toggle next to each bnc connector? The ones I had (DW) did.

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Carter Maslan
Oct 08, 2016
Camio

This is for a Pelco DX8100 DVR. I didn't see any toggle but I have only viewed online photos (haven't been on sit yet). Do you have any recommendations?

U
Undisclosed #3
Oct 08, 2016
IPVMU Certified

Carter, this manual shows the back of the DX8100 looking like this:

If so it has full looping outputs without need of an 75ohm cut switch and tee.

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Avatar
Gianni Viero
Oct 08, 2016
Videotec

Hello Greg

we do offer various video distributors. Please take a look at:

http://www.videotec.com/dep/ekr/Schede_Tecniche/EN/VD_2014_06_19.pdf

thanks

Gianni

MC
Marty Calhoun
Oct 08, 2016
IPVMU Certified

Splitters, TEE's woooo this is not for me.................

U
Undisclosed #3
Oct 08, 2016
IPVMU Certified

Did the title mislead you?

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JS
Jason Spielfogel
Oct 09, 2016

Undisclosed #3 is correct that you can loop Analog feeds through a DX8100 without need of a Distribution Amplifier (which is the term everyone was hunting for but never specifically mentioned).

It's important to note however that the DX8100 is not a DA and doesn't amplify the loop-through signal. In most cases this is fine, and it's what the DX8100 was designed to do, but depending on cable quality and length, you may wish to consider purchasing a DA or "Video Distributor" as referenced.

Side note, the DX8100 was discontinued years ago, and Pelco's entire Matrix line was also discontinued last year.

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