How far can I remote the antennas from a tempest basestation
Using the Remote antenna transceiver (part # CCT-RT) you can remote the whip antenna 450m using Cat5 cable

You can use use coaxial cable to remotely locate the whip antennas, the cable must be a low loss 50 ohm coax.
Recommended cable type is the LMR-195 / LMR-400 low loss RF coax cables
If possible, locate the two whip antennas at least 3m apart from each other, but not more than 15m apart from each other, to add spatial diversity.

Cable Type and Length Considerations
Suggested cable for very short runs
LMR-195 (or equivalent) up to 4m
Equivalent Belden cable has more db loss
Suggested cable for longer runs
LMR-400 (or equivalent) up to 13m
Equivalent Belden cable has more db loss
Use the Remote Transceiver unit if you need to run longer cable lengths