Jan 19 2009
CATV / CCTV Integration
I’ve posted this sort of picture before, it’s what my brother refers to as the “crap on a board” image. This time I’ve taken a second to mark some of the components so I can explain what is taking place in the “crap on a board” picture.
1. RF Modulator - This device takes a composite signal (such as that spit out by your DVD player or Gaming System) and converts it into a specific frequency range which corresponds with an accepted North American television channel.
2. The Composite signal feed. In this case it is the feed from the amplified output from the CCTV system Multiplexer.
3. The new modulated signal is sent back out on the frequency given to channel 75.
4. The Modulated signal is fed into a splitter turned backwards (now acting as a combiner).
5. Unmodified CATV signal is fed through a high/low pass filter which blocks the frequency range assigned to channels 71-78 (leaving them blank - any TV viewing this feed would see nothing but snow on these channels). When the “filtered” CATV feed is combined with the modulated feed a NEW channel 75 is inserted into the CATV signal.
6. CATV Amplifier - Simply takes the new feed and increases the gain somewhat ensuring that the various sets in the house (three different runs) have clear picture.
The end result? Switch on any television in the house and switch to channel 75 and you’ll see the perimeter of the house, nicely labeled and time stamped. There remains room in the 71-78 channel range to insert two more custom channels (anything could be added here).
Not bad, total cost of the modulator/filter/amplifier arrangement? Not counting the cost of the piece of wood approximately $90 CDN.
Pretty slick, huh?
Real damn slick man, if I still had a TV around I would love a setup like this.
I’m guessing that your cable doesn’t have any channels on the 71-78 range?
Gudis: It’s kinda nifty, I actually find myself forgetting that everyone doesn’t have one. Something goes “snap” outside I just change channels and see what it was (or more for my piece of mind, What it wasn’t). I just need to do a little more reading on SATV to see if I can get all three on the one line, I think that’d be a neat selling point for the house.
Jeff: Nah, nothing on that channel range. You can get high/low pass filters for a variety of different ranges, or even a notch filter to take out channel 3 (like most apartment buildings) if you prefer, the options are almost endless.
It’s mainly about the convenience. We’ve tried a few different configurations (hooking up a composite feed into the “aux” input of the VCR or the TV) but most of the options felt like a “cludge”, it just wasn’t convenient to access the CCTV feed, and by the time you’d gone through the steps (usually just locating the OTHER remote control) you’d probably given up and just peered through the window.
Mostly I wanted uniformity from the system. I wanted ANY TV, ANYWHERE in the house to show the same thing, and I wanted it to be expandable so any new TVs showed the same thing when they were plugged in.
It was a good little project. Now I just have to mount the stuff properly and cut some short cables so it looks more like a “video distribution system” and less like “crap nailed to a board”.
-GRIN-
Of course I can’t do that until I’ve sorted out what I’ll be doing with the SATV feed (I mean do I drop a single diplexer onto the CATV feed into the amplifier - I’d need to verify the amplifier handles the right frequency range for SATV) and then just split the signal at each room (say two F-type connects per cover, one for SATV and one for CATV - that’d require somewhere in the neighborhood of a half dozen diplexers).
Meh…more experimentation required.
I finally received that 12VDC programmable timer from Australia - a day short of a month after I ordered (must have been the Christmas rush!) - so it’s back into the workshop today to try and pull all the little pieces together and see if I can get my ‘12 volt solution’ for the cottage working.
Will post a photo once I get it assembled … although you shouldn’t hold your breath - I always seem to be short a connector or fastener of some kind when I tackle these projects
Well, my little 12 Volt Control Centre is built and working … surprised the heck out of me when everything worked first try
Drop by my site and check it out under ‘The Solar Adventure’
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