"Krys" wrote in message
...
It turns out that I have too many transmitters in a small area so the
frequencies are getting on top of each other. I can use half at any
one time. At the moment I have 6 running and am adding them one by one
to see how far I get before I start losing them. Hopefully I won't
have to change the frequencies on too many. Fingers crossed

If they are sending data at the same intervals some will walk on each other
every time.