OK, So I use a tracking system from Communication Specialist, (
www.com-spec.com) and I have the PR100A receiver, which can handle 100 Pre-programed transmitters. The R300A receiver can handle 300 transmitters, again pre-programed, you can not change the frequencies on these transmitters.
Here are the transmitters I use for now:
Channel 00 = 223.110 MHz
Channel 73 = 222.510 MHz
So for what it is worth the R300A also uses these frequencies but they correspond to different channels on it's selector as such:
Ch 00 = Ch 311 on the R300A
Ch 73 = Ch 251 on the R300A
One should note that as I have used these transmitters I have lost some due to them not being secured properly within the rocket, (and the coin battery failed before I could locate it) Or they were destroyed during a crash, (usually in someone else's rocket I had loaned it out to, I don't loan them out any more. ). :-(