Installing the Receiver
G-17
Installing the JR R921
The JR R921 incorporates dual internal receivers, and one
or two remote receivers offering the security of up to four
simultaneous RF links for the ultimate in multi-path RF
security. Two internal receivers are located on the main
PC board, while a third remote receiver must be plugged
into one of the antenna ports in order for the system to
operate. Optionally, a second remote receiver can be
plugged into the remaining remote antenna port giving
a total of four operational receivers. By locating these
receivers in different locations throughout the aircraft,
each receiver is exposed to its own RF environment,
greatly improving path diversity (the ability of the receiver
to see the signal in all conditions).
Note: The JR R921 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 models or in jets (low
vibration), 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 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,
9-inch, 12-inch, 24-inch and 36-inch 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.
