I don't see where an electrifly receiver is recommended by Tower, but that doesn't matter. The standard receiver that came with the radio should work just fine.

What brand of transmitter do you have? Electrifly receivers are not compatible with JR or Airtronics, or any AM transmitters.

As long as you have the crystal that is recommended for the receiver, on the correct channel, it should work. I would contact Great Planes product support at [email protected] for advice. You probably have a faulty receiver or crystal.