Multiple transmitters?
 

Just curious if anyone here runs 3 or 4 agile modulaters at once where two of them are playing a loop of some tv series and the other for just what ever you wanted to play?
Seems like something I would do just for the fun of it:D

TITLE EDIT: multiple not mutile

Is it possible to feed those modulators into a common antenna and have each transmitting on a different channel?

Yes, you can do that. I have 5 modulators tied to a combiner. It is the same sort of thing that was commonly used in motel systems. My setup feeds each of 4 modulators with a digital converter box each tuned to a different local digital channel and a 5th modulator is fed by a dvd player. All 5 modulators feed the combiner, and the combiner output feeds a single coax to the tv sets. The combiner can accept input from 24 modulators and output the signal on a single coax. This is just like the combiner I use.
http://www.ebay.com/itm/Holland-1GHz...item1e763ebf53

Fixed it for ya.


Bob has a nice setup that works well, those combiners are great. I have that kind of setup too but it is dismantled at the moment.

Coaxial splitters work fine as combiners. For 4 channels, connect the modulator outputs to the splitter output, and connect the splitter input to the antenna. Much cheaper than a combiner.

The isolation between ports is important to prevent spurious signals as a result of the output of one modulator getting into the output stages of another modulator. A simple splitter will not provide isolation between the ports.
jr

Thanks!

They do, provided you don't use adjacent channels within each of the three VHF bands.

Jas.

On the ship I used to work on, our cable system was put together in this manner. We had 3 modulators that put out two channels each and DVD players and Dish receivers were connected to the modulators. You could be in any cabin on the ship, and get all 6 channels. I think there were at least two dozen TV's being fed throughout the ship. When the ship went away a couple years ago, the captain let me take the modulators home. I will use them later once my shop is completed. The system worked quite well.

jr_tech, look at the specs for splitters. Typical port to port isolation is about 35 db, probably about the same as a combiner. If you look inside a combiner you will see it is made up of directional taps, which are simply splitters with uneven outputs (splitters provide identical output levels on all ports).

I stand corrected... thanks!

jr

That is good to know. Someday I would like to set up a 6 channel analog TV service in my house using digital converter boxes tuned to favorite digital stations. I currently have one analog channel using a converter box and Blonder Tongue agile modulator on channel 5 and it works quite well. I know better than to use adjacent channels for these things.