| Warning
Using a transmitter as a buddy box can create frequency problems Summary It was found that a battery-less transmitter, used as a buddy box, when activated, transmitted not only on the ‘master’ frequency but also on the buddy box frequency. Preamble After several unexplained radio glitches the problem was discovered to be with one of our student training buddy box set ups. After a series of eliminations, the problem was determined to be that the buddy box was transmitting on two frequencies. Not only the master frequency but also it’s own. Equipment Master transmitter Hitec prism on ch 42 Buddy box transmitter Hitec Focus 4 on ch 32 Round DIN to DIN plug, trainer cord (unknown manufacture) Plane 1 on ch 42 Plane 2 on ch 32 Observations 1. The buddy box training system worked correctly with ch 42 master and plane 1 (ch 42) only turned on. 2. Now for the problem:- When plane 2 (ch 32) was also turned on it had some small jittering as one would expect but when the trainer button was activated the buddy transmitter operated all four major controls of both aircraft. 3. The same problem occurred when a Futaba 6XA transmitter was used as the master. Solutions 1.If both tx are Hitec - Use Hitec oneway buddy chord 2. Remove the crystal from the buddy box 3. Take pins for both frequencies from the control board when using the buddy box |