Hi Al,
I see that you're pretty new here, so am going to assume that you don't already have a huge automated display. With that, I'm thinking you're asking a simpler question... Something like - "in a simple installation, do I need one transmitter for every receiver?".
No, you do NOT need to keep transmitters and receivers in "pairs". One transmitter will serve any number of receivers - up to the 512-channel limit of a DMX universe. You only need more than one transmitter in the following cases:
- when you exceed 512 channels,
- when you want multiple unsynchronized, simultaneous displays, or
- when the signal from the transmitter isn't strong enough to cover the whole display area (geographically).
Hope this helps.
--Dave