My Dragonfly heli came with an all-in-one black box (pictured below) containing the RX, 2 ESCs, gyro, and mixer. The crystal is 72.870 MHz, which is channel 54.

Since the TX that came with the Dragonfly is pretty dreadful (and configured for Mode 1!), I was hoping I could change the crystal in the Dragonfly RX and so use a different TX. This did not work.

What I did was to simply unplug the original channel 54 crystal and replace it with a spare channel 42 crystal that I had, then try to operate the heli with my channel 42 TX. There was no movement of any of the heli functions. I even tried both single- and dual-conversion channel 42 crystals, though I seriously doubt the Dragonfly RX is dual-conversion.

Do these cheap all-in-one systems have a proproetary modulation scheme that prevents their use with standard RC transmitters? I read this in another forum.

Thanks,
Jeff