CCTV on every tv in the house

[fas 0]

I am designing a home system for someone who wants to be able to watch each camera on every tv in the house. All the cable runs are homerun to a location. I will need a 4 channel modulator to broadcast the cameras on 4 unused channels, and possibly a channel filter. How do I modulate each individual camera? I am thinking that it needs to be connected to the modulator before it gets connected to the dvr. Should I use a 2 way splitter to connect to both the dvr and modulator?

[CollinR 0]

Do they really need each camera independently?

 

If not you can do it on 1 channel if your DVR will output a baseband multiplex.

 

Otherwise yes you can use 4 single channels or 1 4 channel modulator to get it to the UHF/VHF channels of your choosing.

 

 

This can really get complicated if they are using a digital service over the incoming coax, it can be done but the more channels, crappier modulators and notch filters you use the more likely you'll have an issue.

 

You amplifly (bi-directional and high frequency) and split the incoming signal 1 passes straight to their cable modem. One can go to be split off for all the TVs in tha house and the other gets filtered and injected. If everything is kosher you can install a splitter backwards between the modulator output and the passthrough cable before splitting it out to the TVs.

[spyman99 0]

Recommend the ChannelVission 4 channl Modulator, you will also need 4 diplexors, and 4 low pass filters if you want 4 camera images on 4 different channels.

 

You can, depending on your DVR send from video out (quad) to a single channel modulator with diplexlor and low pass filter to save costs.

[rory 0]

There are different ways to do this, but here is how i recently did a 3 channel version ..

 

3 Outputs from the Multiplexer (or DVR in your Case), requires loop out, or you could use a T-connector but ive never used them myself. Those ouputs go into the 3 inputs on the 3 Channel RF Modulator which is sitting right by the DVR.

 

Then a RG6 Cable TV Coax goes from the output on the RF Modulator run to where the cable TV main cable splits off to go out to the TVs in the house.

 

Right before the split use a 2 way splitter (2 in - 1 out) and connect the Coax from the RF Modulator into one, the Cable TV Cable into the other.

 

Then add a single low pas filter inbetween the 2 in 1 out splitter, and the cable that goes to split off to the other TVs in the house. That filters out 4 channels and the channel range depends on which filter you purchase, in my case it was channels 71-78, and set them to Channels 72, 74, and 76, as you have to skip a channel - so if using a 4 channel Modulator it could be for example 72, 74, 76, 78, or 71, 73, 75, 77 ...

 

Thats all there is too it, this is not for Digital Cable though.

 

This is the modulator i used:

CVT3ub/uhf-II

# 3 input, table-top design

# Ultra Band 65-135*, UHF 14-78 (Excluding 95-99)

# PLL crystal controlled oscillator

# Non volatile memory

 

 

But you would probably want this one for 4 channels:

E4200

# Economical 4 Input Ultra Band 65-135

# UHF 14-78 (Excluding 95-99)

 

Filter:

3205/71-78

# Low/High Pass Tier Filter

# Blocks CATV 71-78

# 2 channel slope

[fas 0]

I have set up many cable systems for customers with modulated channels, digital cable, directv, so I am aware of all the things that must be done other than how to individually modulate channels from cctv. Can I do this:

 

Run the cctv feed from the camera into a 2 way splitter, and run one end of the splitter into the dvr, and the other end into the modulator? If I do this, does everything need to be bnc to some other type of connector? Thanks.

[rory 0]

BNC or RCA, doesnt matter, but must be Composite.

 

Which DVR is it, and does it have a loop out?

 

Rory

[fas 0]

Ok, is this the best way to do it:

 

- rg59 from camera terminated with f connector into the in on a 2 way splitter

 

- rg59 terminated with f connectors coming out of the 2 outs on the splitter

 

- one out goes into a modulator terminated with a bnc connector and a bnc to rca connector.

 

- the other out goes to the dvr terminated with a bnc connector.

[rory 0]

When you say F connector .. that doesnt sound like its BNC/RCA .??

You need to use Composite into the RF Modulator, then output with CatTV connectors and coax.

 

The cheapest way if the DVR doesnt have a loop through/out, and you dont have a quad or CCTV Video Distributor, is to use a BNC T-Connector.

 

Rory

[fas 0]

I don't know what a bnc t connector is, but I am guessing it is a splitter that allows the signal to go to 2 places. If that is the case, that would be the easiest and cheapest, but does it need to be amplified? Also, how come you didn't do it that way?

[rory 0]

I used multiplexers, which have loop outs, so no need for T-Connectors. I used short RCA Cables, since the input on the RF Modulator is RCA, and I used RCA-BNC adaptors for the connection to the Multiplexer Loop outs. If the RF Modulator is right next to the DVR/Mux, then no need for amps. If the distance is far from the RF Modulator to the Cable TV split, then you may want some CatTV Amps. Depends on the app. In my case the Cable TV out to the TVs were amplified already in an OnQ box, and the distance from the RF mod to the Cable TV split was less than 50'.

 

Rory

 

T-Connector:

[fas 0]

rory,

 

How do you connect to the t connector? I'm guessing the in from the camera goes to the single bnc male end, and the other open ends go to the dvr and the modulator. But how do you connect the ends that go to the dvr and mod to the t connector?

[rory 0]

The BNC Male end goes into the DVR input, the Output from the camera goes into one of the Females, and the output to the RF Modulator goes on the other female end. Personally i rarely use them myself though. You twist it so the Female ends point upward and downward, so that they clear the other BNC inputs on the DVR.

[fas 0]

Do you have a picture of that?

[rory 0]

not an actual photo but would be something like this:

[excuse the shabby paint shop job]

[fas 0]

Rory,

 

Thanks for going through the trouble of making that picture. I understand now. Thank you.

[lphillippi 0]

I tried this using a BNC-T and the image quality was pretty bad. Anything special about the T that should be used?

[securitymonster 0]

how far were the cable runs with the T-Adapter?

[JMANOFNVS 0]

Man Rory an F connector is the screw cable input on the back of a TV. Check these links out.

http://www.channelvision.com/pdf/support/guide/modulationMethods.pdf

http://www.channelvision.com/pdf/support/guide/diagramsLayouts.pdf

http://www.rldrake.com/

http://www.channelplus.com/products_rf.html

That should more then cover your needs.

[securitymonster 0]

JMAN saves the day! Nice Diagrams.......

 

Oh, and Happy Birthday !!!

[G-MEN 0]

Or you can use these instead of T adapters http://www.channelplus.com/product_detail.php?productId=36

[normicgander 0]

If the picture is "bad" it could be because the the video transmission cable is double terminated. The source impedance is 75 ohms and should be terminated to a single 75 ohm load. Loop though connections we see on monitors and DVRs, especially newer equipment, accounts for the impedances and loop output connections (when you connect the loop output the 75 ohm termination resistor is disconnected). For old guys like me, you may recall when equipment had 75/hi-Z termination switches. What happens in a double termination, the source (camera) drives two 75 ohm loads and you lose 6db of signal. On long cables runs the picture can be lose sync, but in general the picture will be much darker. On a waveform monitor, this 6db loss would be a reduction of about 50 IRE units of the maximum allowable white level of 100 IRE units. BNC T adapters can be used if one of loads is "Hi Z" (>7.5Kohms).

[fas 0]

What's the best way to split the signal then so that one connection can go to the dvr and one to the modulator?

[rory 0]

use the loop through on the DVR.

[normicgander 0]

Rory is right, but the question is does the DVR have loop through connections?

 

fas- If there are no loop through connections, then a 2 channel composite video distribution amplifier is needed.

[fas 0]

What are loop through connections?