JR R921 Receiver
G-10
The R921 receiver combines two internal with one or 
two (optional) remote receivers, offering superior path 
diversity. The radio system simultaneously transmits 
on two frequencies, creating up to four RF paths on two 
different 2.4GHz channels. This multi path redundancy, 
plus the fact that each of the up to 4 receivers are located 
in different locations throughout the aircraft exposes each 
to a different RF environment creating a superior RF  
link in all conditions. The JR R921 allows the use  
of an optional Flight Log Data Recorder (SPM5940) to  
be used. The flight log plugs into the data port and 
provides quality of RF link data of the previous flight 
allowing the confirmation of the operational performance 
of the systems.
Features
• 9 channels 
• 2 internal receivers
• 1 or 2 (optional) remote receiver(s)
• Patented multi-link technology 
• Two types of fail-safe—SmartSafe and Preprogrammed fail-safe
• Flight Log compatible
Specifications
• Number of Channels—9 
• Modulation—DSM2 
• Band—2.400 to 2.4835GHz 
• Dimensions (WxLxH)—.35”x2.06”x0.55”
• Weight—Main 15g/.6oz Remote 3g/.2 oz each
• Current—70mA
• Voltage range—3.5 to 9.6V
Note: The X9303 2.4 is compatible with all current Spektrum DSM aircraft receivers including:
AR6000 6-channel parkflyer receiver 
AR6100 6-channel 3.5-gram parkflyer receiver
AR6200 6-channel full-range receiver
AR7000 7-channel full-range receiver
AR9000 9-channel full-range receiver
Important: When using the X9303 2.4 with parkflyer receivers (the AR6000 and AR6100), it’s imperative that these 
receivers only be flown in parkflyer-type aircraft (small electric airplanes or mini and micro helicopters). Flying 
receivers designed for parkflyers in larger aircraft could cause loss of control.