A question for the Uber-Geeks out there!

I co-worker asked me this, and I think it's impossible, but I thought I'd toss it out:

Is there any way to add a signal to your cable TV RG59 and have it show up as another channel? In other words, say your analog cable goes to channel 88, and you want to add another "non-cable" signal so it shows up as channel 89, is there any was to add and modulate this signal?

The guy is trying to add a security monitor to his cable TV and it started me thinking about playing with ananlog OTA reception (don't ask).

I have heard STB-type devices mentioned on the forum that apparently combine dissimalar sources into one output for the TV and wondered if anybody had ever done this...

PS. The "Uber-Geek" comment is intended with complete respect

Grumpy Bob,

Doesn't look too difficult. Perhaps I could suggest something like the Radiio Shack #15-1243 (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F003%5F010%5F001%5F000&product%5Fid=15%2D1243) It's about $25, accepts composite video and sound, and outputs RF on a selectable UHF or cable channel. Add a combiner and you're done. Cheap test, anyway.

ToddK

A device I got from Skyvision years ago adds 4 channels to my TV system. The added channels must be analog and must be in the range 14-64. Each new channel wipes out the adjacent channels due to the use of cheap sideband filters. In other words, you must find groups of 3 adjacent empty channels. For example, if you want to put your DirecTV receiver on channel 23, then channel 23 must be empty and channels 22 and 24 must have no stations that you will ever watch. The unit works well. See http://www.hdtvprimer.com/ISSUES/my_tv.html . Similar units, possibly from the same maker, are now available at Radio Shack.

>>Each new channel wipes out the adjacent channels

Thanks Ken.

Knew there would be twist somewhere...

I noticed on the back of my Mits there are 3 coax RF antenna inputs. One is labelled DTV (connected to ATSC tuner) and two labelled A and B (connected to NTSC tuner). I only use the A input and do not really know what the B is for, but if it is connected to additional NTSC tuner I would assume you could connect one to cable and one OTA or some other device like a closed circuit surveillance system.

>>I would assume you could connect one to cable and one OTA or some other device like a closed circuit surveillance system.

Yes.