Feeder Antennas
The AR9300 incorporates feeder antennas, which are designed to be easily mounted through the
fuselage in carbon airplanes. The main receiver has two 8-inch feeder antennas and the remote
receiver has one. Each feeder antenna includes a coaxial portion (which can be thought of as an
extension) and an exposed 31mm tip antenna. The last 31mm is the active portion of the antenna.
Step 1. Identifying the Types of Carbon Aircraft
While some sailplanes are full carbon construction, most only use carbon in areas that require extra
strength. Many of the latest sailplanes are constructed with 2.4GHz-friendly fuselages meaning that the
forward section of the fuselage is constructed from non-conductive materials like fiberglass and Kevlar
that don’t affect the RF signal. The first step in a proper installation is identifying the type of aircraft
which will fall into one of three categories below.
A. Full Carbon
All components of the airplane including the entire fuselage,
the wing and tail are constructed of carbon fiber or have a
carbon fiber weave throughout the aircraft.
This type of aircraft will require that all antennas
be installed externally.
B. 2.4GHz Friendly Fuselage with Carbon Wing
The section forward of the wing is constructed of non-
conductive materials like fiberglass, Kevlar, etc. but the
wing and possibly the tail section have carbon or carbon
weave construction.
Antennas in the nose of this type of aircraft can be
installed internally while an antenna installed behind
the wing must be mounted externally.
C. 2.4GHz Friendly Fuselage with Molded
Non-Carbon Wing
The section forward of the wing and the wing itself is
constructed of non-conductive materials like fiberglass,
Kevlar, etc. The wing may, however, contain a carbon spar,
which is an insignificant volume of carbon to have an effect.
The tail section can be either carbon, carbon weave or
fiberglass construction.
All antenna can be mounted internally forward of the
wing in this type of aircraft.
Step 2. Determining Antenna Mounting Positions
After determining the type of aircraft from the list above, use the above illustrations as a guideline
as to where the feeder antennas should be mounted. The goal is to mount the antennas in a location
such that at least two will always be in the RF visual line of sight of the transmitter (i.e. not blocked by
carbon fiber structures) in all attitudes. This can easily be visualized by having a helper stand about
20 feet away and rotate the airplane in all attitudes confirming that in all positions there is a direct line
between you and at least two receiver antennas that aren’t blocked by carbon fiber structure.
Note:
If you have a full carbon sailplane, it is highly recommended that an optional fourth receiver
with feeder antenna be installed. Carbon Fuselage Remote (SPM9546)
AR9300 User Guide
Spektrum’s AR9300 9-channel receiver is designed for carbon fiber aircraft installations. Carbon Fiber
can create an RF shielding effect that can significantly reduce radio range when using conventional
receivers and antennas. The AR9300 features an antenna design that overcomes RF issues in these
critical environments.
The AR9300 receiver features DSM2
™
technology and is compatible with all Spektrum
™
and JR
®
aircraft radios that support DSM2 technology including Spektrum DX7, DX6i, DX5e, JR12X,
JRX9303, and Spektrum Module Systems.
Note
: The AR9300 receiver is not compatible with the Spektrum DX6 parkflyer transmitter.
Features:
• 9-Channel receiver optimized for carbon fiber fuselage installations
• Double-stacked design offers compact cross section ideal for sailplanes
• Through-the-fuselage, feeder antennas offer superior RF coverage
• Includes two internal and one remote receiver. Additional remote receiver optional
• Preset failsafe system on all channels optimized for sailplane applications
• QuickConnect
™
with Brownout Detection
• Optional Flight Log (recommended) confirms RF link performance and installation
before and during flight
• Includes DVD installation and setup video
Applications
Airplanes with Significant Carbon Structure Including:
Carbon/Composite Sailplanes, Carbon/Composite Jets and Aircraft with significant conductive
materials (Carbon, Aluminum or other metals) that could attenuate (weaken) the signal.
Specifications:
Type: DSM2 Full Range Receiver for Carbon Fiber Aircraft
Channels: 9
Modulation: DSM2
Dimension (WxLxH): Main: 20.8 x 40.82 x 19.25mm
Remote: 20.25 x 30.05 x 7.45mm
Weight: 18.23 g (main receiver)
Input Voltage Range: 3.5–9.6V
Resolution: 2048
Compatibility: All DSM2 Aircraft Transmitters and Module Systems
Antenna Length: Main: 203mm (2)
Remote: 203mm (1)
Receiver Installation in Aircraft
Airplanes with significant carbon fiber construction can create an RF shielding effect, reducing range.
The AR9300 is designed to overcome these critical RF issues in carbon airplanes by outfitting the
aircraft with external antennas when necessary at specific points that will ensure secure RF coverage.
Step 3. Installing the Receivers
Install the Main receiver in the normal position recommended by the airplanes’ manufacturer, noting
that the data/bind port should be easily accessible as a flight log will be used to confirm RF link
performance. Double-sided tape or foam can be used to secure the main receiver in place. Using
double-sided servo tape mount the remote receiver(s) within 3 inches from where you intend on
having the antennas exit the fuselage.
Step 4. Mounting the Antennas
Three 2.4GHz Antenna Exit Guides (SPM6824) antenna mounts (with tubes) are included to make
external mounting easy. To install the antenna mount, drill a 1/8-inch hole in the desired antenna
mounting position; then, using a hobby knife slot the hole as shown.
Insert the tube in the mount; then using medium CA, glue the mount and tube in place in the fuselage.
Trim the tube to length inside the fuselage if necessary. Now slide the feeder antenna through the tube
until the 31mm tip completely exits the mount. Using a drop of CA, glue the antenna to the mount
making sure that the 31mm active portion of the antenna tip is fully exposed.
Note:
If the antenna is to be mounted internally (in the front of a 2.4GHz friendly fuselage) the coax
can be taped into position. Be sure the 31mm tip is located at least 2 inches from any significant
carbon structure and from the battery.
Step 5. Plugging in the Servo Leads
Plug the servo leads into the appropriate servo ports in the receiver noting the polarity of the servo
connector. Note that the signal wire (orange for JR servos) faces toward the center of the receiver.
Consult your radio’s manual for specific detail as to which servo plugs connect into which servo port
channel.
Step 6. Binding the Receiver
Binding
The AR9300 must be bound to the transmitter before it will operate. Binding is the process of teaching
the receiver the specific code of the transmitter so it will only connect to that specific transmitter.
1.
To bind an AR9300 to a DSM2 transmitter, insert the bind plug in the BATT/BIND port on the receiver.
2.
Power the receiver. Note that the LED on the receiver should be flashing, indicating that the receiver
is in bind mode and ready to be bound to the transmitter.
3.
Move the sticks and switches on the transmitter to the desired failsafe positions (normally mid flap
for dethermalizing).
4.
Follow the procedures of your specific transmitter to enter Bind Mode, the system will connect
within a few seconds. Once connected, the LED on the receiver will go solid indicating the system
is connected.
5.
Remove the bind plug from the BATT/BIND port on the receiver before you power off the transmitter
and store it in a convenient place.
IMPORTANT
: Remove the bind plug to prevent the system from entering bind mode the next time the
power is turned on.
Step 7. Radio Setup and Programming
Following the instructions in your radio manual, program your airplane.
Step 8. Rebinding the Receiver
After you’ve programmed your model, it’s important to rebind the system so the true failsafe control
surface positions are set.
Step 9.
Ground Range Testing and Verification with Flight Log
Advanced Range Testing Using a Flight Log
In airplanes that have significant carbon fiber construction it is imperative to first do a ground range
check using a flight log. This ground range check will confirm that the internal and remote receivers
are operating optimally and that the antennas are properly mounted in a position that will give positive
RF coverage in all attitudes. This Advanced Range Check allows the RF performance of each receiver
and the positions of each antenna to be verified and to optimize the locations of the antennas.
Advanced Range Test
1. Plug a Flight Log (SPM9540) into the data port in the AR9300. If the port is being used for the
battery, a Y-harness can be used or plug the battery into any other unused port.
2. Turn on the system (Tx and Rx).
3. Advance the Flight Log until F- frame losses are displayed by pressing the button on the Flight Log.
3. Have a helper hold your aircraft while observing the Flight Log data.
4. Standing 30 paces away from the model, face the model with the transmitter in your normal flying
position and put your transmitter into range test mode. This causes reduced power output from the
transmitter.
5. Have your helper position the model covering all orientations (nose up, nose down, nose toward the
Tx, nose away from the Tx, etc.) while your helper watches the Flight Log noting any correlation
between the aircraft’s orientation and frame losses. Do this for one minute. The timer on the
transmitter can be used here.
6. After one minute release the range test button and read the data from the Flight Log. A successful
installation will yield the following:
0 - holds, less than 20 Frame Losses
It’s common to see high values on individual receivers as the carbon structure can block the signal
in various orientations. What is important is that at least two receivers are receiving well at all times.
If more than 20 frame losses or any holds occur redo the test noting the aircraft orientation when
the fades and holds occur. This will allow you to change and optimize the antenna position(s) to a
better location.
Step 10. Short Test Flight Verification with Flight Log
When the system tests successfully as directed above, it’s time for a short near test flight. This first
flight should be close (less than 500 ft and about five minutes). After the flight, land your aircraft
nearby (less than 60 ft away)* and check the Flight Log data. Again a successful flight will result in 0
holds and less than 20 Frame losses. Extend the flight distance and times checking the Flight Log data
after every flight until you are confident with the results. Many pilots choose to mount the Flight Log in
the airplane making data checking convenient.
*If the sailplane is landed more than 60 feet from the transmitter the system may experience higher
than normal frame losses and holds. This is because the antennas are within inches of the ground and
the signal can be blocked by the ground causing RF link degradation. Note that when landing more
than 60 feet from yourself, high flight log values are normal.
Important: Y-Harnesses and Servo Extensions
When using a Y-harness or servo extensions in your installation, it’s important to use standard non-
amplified Y-harnesses and servo extensions as this can/will cause the servos to operate erratically
or not function at all. Amplified Y-harnesses were developed several years ago to boost the signal
for some older PCM systems and should not be used with Spektrum equipment. Note that when
converting an existing model to Spektrum be certain that all amplified Y-harnesses and/or servo
extensions are replaced with conventional non-amplified versions.
Preset Failsafe
The AR9300 features Preset failsafe only. Preset Failsafe is ideal for sailplanes, allowing the aircraft to
automatically dethermalize if signal is lost. With Preset Failsafe, when signal is lost all channels go to
their preset failsafe positions (normally mid flap) preventing a flyaway.
• Prevents flyaways should the signal be lost
• Eliminates the possibility of over-driving servos
Receiver Power Only
• When the receiver only is turned on (no transmitter signal is present), all channels have no output
signal, to avoid overdriving the servos and linkages.
Note:
Some analog servos may drift slightly during power-up even though no signal is present. This
is normal.
Shown using a separate receiver pack.
(Battery can be plugged into any open port.)
When binding through an ESC, the ESC’s lead must be plugged
into the port operating the motor, typically the gear or AUX2
channel. The servo monitor is helpful in determining which
channel is being used.
External
antennas
Internal
antennas
External
antennas
Internal
antennas
Optional
location
Full Carbon
2.4GHz Friendly
Fuselage with
Carbon Wing
2.4GHz Friendly
Fuselage with
Molded Non-
Carbon Wing
AR9300 installed in a Supra.
31 mm
203mm
1. 13 D i ameter
