Is it possible to view a modulated channel on an un-used satellite channel? I would like to do this so I do not have to change video sorces on my TV to watch the channel. Also, can I use combiners to combine multiple modulators? Thanks...

Well anything is possible I suppose but here are a couple problems based on what I think you are asking. I am assuming you are running video to your TV, that rules out modulation of an RF signal into the video signal. You can't inject channel 40 in the lnb coming into the receiver. So your only option would be to modulate into to the "Antenna In" of the receiver and in theory that should be all you need to do. Now you will have to setup the off air tuner in the Sat receiver but after that it becomes a button on the Sat Receiver remote!

As to your 2nd question, yes you can combine several modulators. Just be sure to read the instructions for channel selection. Most will say to choose a channel with no signal on the one you use and the one below and above. Also, there are a few different manufactures that make a double or triple channel modulator in one unit so you may not need to get more than one.

You cannot add a channel to the satellite channel lineup; that would be breaking into the sat company's digital encode/decode stream, and is reserved for the likes of the NSA, etc.

If you are using an HD sat receiver with an internal NTSC tuner is it possible to modulate a channel into that input. Most (all?) non-HD sat receivers do not have an internal tuner, so the antenna in/tv out is a pass-through only.

With cable --

When you choose the channels you modulate onto, don't forget that the digital channels are somewhere in the spectrum! They are usually in the channels above the high 70s, at least throughout southern California. You can't tell where they are until you try to use a channel for a modulator, mix it into the cable signal, and find the signal is messed up. The cable box doesn't tell you what channel it is really on and an analog TV won't likely even see the digital channel to tell you to expect interference.

I would start trying channels at 100 and go up from there. You might have to even buy a low-pass filter that removes some upper cable channels in order to get a modulated signal onto the system. But that removes some digital channels, so....

Actually this can be done but is pricey!!!! All of the new Best Buy hd distribution systems are set up like this. Can't think of what the name of the box is but the signal from the LNB feeds into it and the output goes to the multiswitch. They then just use standard DirecTV HD recievers (samsung) to feed the TV's. The box takes a video feed in from their marketing material. It will automatically interupt the satellite signal and inject it's own programming as a satellite feed.

Thanks for your replys... I currently have the RF out of my sat receiver feeding other TVs in the house. It is connected via s-video to my main TV. I temporarily modulated my front door camera through a VCR and combined it with my sat line. I split it at the receiver to sat input and antenna input. Now if I turn off my say receiver I can view the camera on my other TVs, but not the main one. What I would like to do, is modulate satellite, DVD, and PS2 from living room to all TVs. Plus 2 or 3 camera channels modulated from basement. I would rather not put a modulator in my living room though, so I figured I would forget the PS2, and possiblly install a DVD player somewhere else to feed the other TVs. I was also considering locating all my equiptment from the living room to a closet, but I do not want to sacrifice picture quality. Thanks again for any input...