Putting CCTV feed on a TV station.

[mdshunk]

Put this question in "computer and data wiring", since this category is the closest.

Problem: Customer has a CCTV color camera at the gate at the head of the driveway. The camera is piped to a dedicated monitor in the kitchen of the dwelling with about 1200' of RG6 quad shield. The customer wants to put this camera feed "on a station" and connect this cable in with the house's TV cable. Customer wishes to tune to an unused station (like, say 98 or 99) and view the camera feed on any set in the home. What is the equipment called that can take a camera feed and put it on a station?

[Unregistered]

He would need a modulator - they come in fixed channel output or agile(tuneable)

[dznewz]

You can get modulators for this purpose at www.smarthome.com and other places. You might be able to get one at Radio Shack.

You'll also need to use a 75 ohm coax splitter as a combiner to merge the incoming cable signal with the modulator output.

[dkerr]

http://www.bassburglaralarms.com/subcategory_252.htm?OVRAW=audio%20video%20modulato r&OVKEY=audio%20video%20modulator&OVMTC=standard

http://www.starkelectronic.com/btp30.htm

http://www.kandbelectronics.com/kb-electronics/3025.html

http://www.nextag.com/buyer/outpdir.jsp?nxtg=3bf68c_881A9E76B6C91421&OVRAW=audio+video+modulator&OVMTC=standard&search=audio+video+modulator&OVKEY=audio+video+modulator

Try these sites out for starts, or search for video audio modulator combiner

[mdshunk]

Thanks, guys. It makes perfect sense now.

[suemarkp]

One other thing not mentioned. If this person has cable TV, there may be signals that you can't see on the channel that you choose to modulate the camera onto. You can buy filters that chop off everything above a certain channel (typically in the 60's, 70's or 80's), or you can buy a notch filter that takes out a chunk of about 10 channels. You usually need the adjacent channels unused when you modulate your own signal onto it.

I bought a cheap insertion filter that allows my own signal to be inserted onto channel 3 (it blocks out the CATV channel 3 which I never watch). However, channel 4 seem to mess with it occasionally so I abandoned that insert device.

I'd plan for more cameras if you can (4 seems to be a common implementation). For this reason, an 8 to 10 channel notch filter allows you to use all 4 cameras on nearby channels (e.g. 61, 63, 65, and 67 on a chan 60-70 notch filter). Wait until they price a 4 channel modulator though! Also, be advised that UHF channels and CATV channels are not the same, so make sure your filter, TV system, and modulators are on the same page. Finally, be aware that CATV channels 95-99 are not above channel 80 in the RF spectrum -- they are ******* channels somewhere else in the mix.

[mdshunk]

I've been researching these modulators a little bit since I learned about them the other day. It seems that I'm gonna spec a 4 input modulator anyhow, since I'd hate to be the guy who installed something that was "full" from the beginning. I have also learned that there needs to be a blank channel between the channels that the modulator outputs on. For instance the modulator can put a picture on 13 and 15, but not 13 and 14. So a four channel modulator would need 8 broadcast channels (if they were all in a row). Most of the ones I've looked at go up to channel 123, so I should be able to find some blank room in the cable tv lineup somewhere.

My only concern so far is the 1200' run from the camera. It looks pretty decent on the piece of crap monitor. After I put it throught the modulator (and it's associated dBmV losses), and the premisis wiring and other splitter losses... how will the camera picture be on a really nice television somewhere in the house? I guess I'll find out soon enough.

[suemarkp]

Boost the signal at the camera if you need to. Fortunately, the camera video is baseband, and about 4 MHz of bandwidth. The cable losses at 4 MHz are much less than they are at 500 MHz. But that is a long way to drive a camera....