Jul 15 2008
Video Modulation / Distribution - Phase I
Ok this is the basic mock-up for the home video distribution system. By way of an explanation here’s what it does.
The CATV feed comes in through a high/low pass filter (the silver cylinder - that blocks the frequency range assigned to channels 71-77) and is then fed through the combiner (the brass two in/one out thing). On the other side of the combiner is the “modulated” composite signal from the Multiplexer, the modulated signal is set to show on the frequency range assigned to channel 75 (which has been made clear by the high/low pass filter mentioned above).
Realistically instead of a generic combiner splitter I should have a combiner/distributor which has two in (CATV feed + Modulated CCTV system feed) and eight out (eight feeds for televisions within the house, amplified to prevent signal issues). The one I had does not appear to work in any useful fashion, and I’m in the process of obtaining a replacement.
The entire arrangement would then be moved into a fancier housing, and some blinking and flashing LEDs added (simply because they’re so cheap on ebay, and I love Airplane! - and yes that was an Airplane II reference, just let it drop, ok?).
This has got to be your best article on the CCTV so far. That whole “brass two in/one out thing” description is excellent!
Really though, I do enjoy reading your trying to see what’s outside the house from inside the house exploits. Now if it was all as easy to understand as “b t i/o o t”, I might actually know waht was going on.
-GRIN-
Thanks Jeff! I know most of the CCTV stuff on this website is presently being used on insomniacs that don’t respond to heavy medication and I’m trying to make the subject matter a little more approachable and entertaining.
I’m hoping to break it down to a bunch of bite sized articles that can be more easily digested by my six readers.
Stand by for more “B T I / O O T” stuff coming up.
So with the pass filter you can pick the channels?
I was just wondering what was on the channels you gave up.
Or is it like, channel 3 is cable TV and 70 is cctv?
Is channel 70 a multi-plexed image, or can you set it to give you
a camera per channel (70=camera #1, 71=camera #2, and so on)?
How much more work would it be to have one of the “Pan/Tilt/Zoom” cameras?
And lastly, when is the internet stream coming on-line?
Piet: high/low pass filters are available in different frequency ranges, but generally cover an 8 (eight) channel range, I purchased this one specifically because there’s nothing on TV in the 71-78 channel range (except for like CSPAN or the “Insurance Adjusters Network”), I also have a Notch Filter which will chop out channel 3-6 or so, but theres more interesting stuff down there.
Channel 75 is a direct feed off the multiplexer, so it’s a quad screen split with one of the quads flipping between two cameras, like so (although this is an outdated screen cap from the old windows software, and most of the cameras have been upgraded, same idea):
I can get a channel per camera, but I’d need a modulator for each feed I’m inserting into the CATV feed. I had figured that I’d add a second feed for the video output from the DVR system just so I can verify that it is running etc, but that’s down the road.
PTZ cameras vary in price, a basic HK pan/tilt camera with a remote (wireless) control weighs in around $100-150, pretty basic. A proper PTZ camera, housing and controller is a bargain at around $500-750, making it more expensive than my entire system up to this point.
Internet? No, no internet feed just yet as Zoneminder doesn’t have an built in security, although I may make a public feed available from one of the cameras (either the dogpoop or neighbor-cam) when those projects are completed.
Nifty, huh?
Looks pretty spiffy, but yup … needs some flashing LEDs, a couple of digital readouts and one or two analog meters … how about ‘Intruder Level’ ?! LOL!!
Yeah, “Threat Level” LEDs.
An ominous voice that said things like “Perimeter breached” or “Self destruct sequence initiated” would be kind of cool.
Might be outside the scope of the project. Frankly I was expecting the LEDs to form part of a power distribution board I had envisioned as part of the wiring clean-up, as part and parcel of that I figured a few fuses and some LEDs indicating power to each unit as a good idea (alternating color flashing LEDs are only slightly more expensive than generic single color LEDs, so there’s the flashing LEDs.)
As for the beeping, well we have eliminated the beeping. I have an old UPS of Dads that I took apart and mangled the little piezo when I replaced the battery, the UPS works fine and there’s no annoying beep to wake Lisa when the power drops in the wee hours. I’ll be modifying the other UPSs similarly, if I haven’t figured out the power is out and they need shutting down then a recurring beep isn’t going to help (although I suppose a few minutes with a multimeter and I could rig an LED to the output intended for the piezo and get a visual alarm instead…hrmmm…).
Give me a little while on this, the new dwelling for the surveillance system should be kinda disco when it’s done. Asthetics were a consideration for the first time, and I’m looking forward to showcasing the results.