Model Aircraft Airtronics RC 4-Channel Transmitter, Receiver and

Complete Airtronics 4-Channel Digital Proportional model aircraft remote control system.  System uses channel 54 of the 72 MHz RC frequency band.  Complete system functionality was just verified using the existing Ni-Cd batteries after 30 minutes charging.  Batteries are more than 5 years old and should be replaced before use with aircraft in flight.  Please note that Airtronics battery connections are reversed from that used by most battery manufacturers.  The batteries included with this system have had Airtronics connectors spliced to the battery leads.  You will need to do the same with new batteries.
The included receiver is a 72 MHz four channel dual conversion narrow band receiver operating on Channel 54.  It worked well in the past with other 72 MHz transmitters operating on different channels on the flight line.
The four proportional servos are Hitec HS-425BB with ball bearings on the main drive shaft.  I don't know what their rated torque is but they were more than sufficient to manage the control surfaces and throttle of the 40" wing span trainer aircraft this system was installed in.
A battery charger for the system is included.  It provides a 12 volt output for the transmitter battery and a 6 volt output for the receiver's 4.8 volt battery.  The charging active LED for the 6 volt output does not work.  It does charge the battery however.
A battery connect harness for the receiver is included.  It provides an external to the aircraft On/Off switch and a battery charging port.
I have included a training cord for connecting a training control unit to the main transmitter.  Unfortunately I no longer have the training control unit.