CCTV distribution over Coax (TV cable)

[franktate]

Before setting out on this latest project I have a quick look in the projects section to see if I could borrow someone elses ideas. Having found no similar projects I thought I would post my solution.

Problem: Viewing the 4 CCTV cameras from arround the house.

Journey: Tried to connect to PC and distribute over network. Problem with converting signal to TV format and problem with changing channels.
Looked at 2.4G wireless distribution. Too much interferrance.
Looked at 5.8G wireless distribution. Still too much interferrance.


Solution: 4 modulators which take the CCTV feeds and convert them to an UHF signal. Put these 4 into the loft between the ariel and the distribution amp.
Alanlog TV has been switched off in my area. Digital TV reception has not degraded following installation.
Also split the signal in the loft to go to modulators and to the PC.


Outcome: Now have all TV's in the house showing all four feeds via their analog tuners (which just about every TV has).


Cost: Total £425
4 RF Modulators - £17 each
2 phono extention cables to reach to PC - £7
4 Swann cameras (600s and 610s) - £350



The picture on the TV is not quite as good as they were when viewed via the PC. Anyone got any tips for improving?

Diagram attached.


frank

CCTV Modulators.jpg

[toscal]

To help you using your modulator channels I have listed the taboo channels you should avoid.
If modulator 1 is set to 21 then you can't use 22, 26, 30
If Modulator 2 is set to 24 then you can't use 23, 25, 29, 33
If Modulator 3 is set to 27 then you can't use 22, 26 28, 32, and 36
If Modulator 4 is set to 34 then you can't use 25, 29, 33, 35, 39, 43

What I would do is check all terminations, then try the system with just 1 camera connected, and all other modulators disconnected. Then do the same with the next modulator and so on. If the picture is clear then try again with 2 modulators connected and see what happens. Also try different channels.
Personally I would have chosen channels a lot further apart, such as 24, 36, 52 and 60.
I do know some tuners don't like the really low channels or very high ones such as 21, 22 and 68, 69.
Is there a termination switch on the modulator, sometimes you may find 2 switches one is for if there is only a UHF output and no UHF input (probably not applicable to your case looking at your diagram) and the other is for if you have to run long cables. Sometimes these are dip switches.
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