Spektrum SPMMSJR9 - Manual (Page 14)

Spektrum Air Module 1
Note: The AR9000 requires that at least one remote receiver be used.
Install the main receiver using the same method you would use to install a
conventional receiver in your aircraft. Typically wrap the main receiver in protective
foam and fasten it in place using rubber bands or Velcro straps. Alternately in
electric or turbine-powered models, it’s acceptable to use thick double-sided foam
tape to fasten the main receiver in place.
Mounting the remote receiver(s) in a different location(s), from the primary receiver,
gives tremendous improvements in path diversity. Essentially each receiver sees a
different RF environment and this is the key to maintaining a solid RF link, even in
aircraft that have substantial conductive materials, (i.e. Turbine engines with metal
tail pipes, carbon fiber, tuned pipes, etc.) which can attenuate the signal.
Using double-sided foam tape (servo tape), mount the remote receiver(s) keeping
the remote antenna(s) at least 2 inches (51mm) away from the primary antenna.
Ideally the antennas will be oriented perpendicular to each other, however, we’ve
found this to not be critical. 6-inch (152mm), 9-inch (228mm), 12-inch (305mm),
24-inch (610mm) and 36-inch (914mm) leads are available, and in sophisticated
aircraft we’ve found it best to mount the remote receivers in different parts of the
aircraft, keeping the remote antennas as far away as practical from any conductive
materials. A typical installation would include the main receiver mounted in the
conventional location in the fuselage and the remote antennas in the nose (jets) in
the top turtle deck and even in the tail. The optimum location is as far away from
any conductive materials as practical.
Installing the Receiver