It hasn't been said what the outputs of the receivers (Time Warner, VCR,=20 etc.) available are. If appropriate outputs are available, the modulator=20 route eliminates all switching, selection of an input or channel is done=20 with the receiver (TV set) tuner. A little pricey, there are available wireless TV, including HD=20 transmission sets available. Thought I saw some of those in MCM, and=20 probably Cables To Go has something also. On 3/18/2011 9:57 AM, Bob Ammerman wrote: > ----- Original Message ----- > From: "Dwayne Reid" > To: "Microcontroller discussion list - Public." > Sent: Thursday, March 17, 2011 11:41 PM > Subject: Re: [OT] Channel Shifter? > > > =20 >> This may not be suitable from a user perspective, but how about >> having a remotely-controlled relay do the switching for each TV set? >> >> Aromat DS2E-M or DS4E-M relays would work well - I've used them for >> RF switching previously. The "-M" variant is a telcom-grade relay: >> bifurcated gold contacts. >> >> Each relay would select between the outputs of your splitters. You >> may have to use 4-pole relays to get enough isolation - one pole each >> selects between the desired signal and ground and a third pole >> selects one of the first two poles. >> >> The relays would have a local power supply and you would >> capacitively-couple the output of the final relay pole to the output >> coax. One side of the relay coil connects to the + side of your >> local power supply, the other side of the relay coil connects via an >> inductor to the output side of the switched coax (after the blocking >> capacitor). >> >> Each TV would have a small box with a toggle switch. Incoming coax >> feeds the switch via an inductor with the other side of the switch >> going to ground. The coax also feeds the TV via another DC blocking >> capacitor. >> >> For extra points, add an infrared detector and PIC to allow >> remote-control of the relay from the same remote that drives the TV. >> >> This may be too much work, but it seems pretty simple to me. >> >> dwayne >> =20 > This is brilliant. I wish it were available off-the-shelf. > > Also, it won't work for my friend because he doesn't have a single point > where all the sets are 'home runned'. Instead groups of two or three sets > tend to be connected to a "sub-"splitter which then runs to the main > splitter in the basement. > > -- Bob Ammerman > RAm Systems > > =20 --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .