I-16
Installing the JR R1221
The JR R1221 incorporates a single internal receiver and three
remote receivers offering the security of four simultaneous RF
links for the ultimate in multi-path RF security. One internal
receiver is located on the main PC board, while 2 remote
receivers must be plugged into one of the antenna ports
in order for the system to operate. A third remote receiver
(included) 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 R1221 requires that at least two remote
receivers 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” 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”, 9”, 12”, 24”, and 36” 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.
In helicopters, there is generally enough room on the servo tray
to achieve the necessary separation. If necessary a mount can
be made using clear plastic to mount the external antenna.
Other important installation tips:
1. The servos should be mounted using rubber grommets and
brass eyelets to isolate them from vibration. Do not over-
tighten the mounting screws; this will negate the vibration
absorption effect of the rubber grommets.
The brass eyelets are pushed from the bottom up in the rubber
grommets. When the servo screw is tightened securely, it
provides the proper security as well as the proper vibration
isolation for your servo.
2. The servo arms must be able to move freely over their entire
range of travel. Make sure that the control linkages do not
bind or impede the movement of any of the servos.
3. Mount all switches away from the engine exhaust and
away from any high vibration areas. Make sure the switch
operates freely and is able to operate over its full travel.
Installing the Receiver