RE: Txmtr vs. Recvr compatibility?
The Tower rx is essentially a Futaba 127DF rx which responds to a negative shift FM signal from the tx. In the USA Futaba (and Hitec) tx's generate a FM (PPM) signal which is a negative shift, whereas Airtronics (and JR) tx's utilize a positive shift. Your Airtronics tx cannot communicate with the Tower rx because of this shift difference. In addition to an Airtronics rx, you could use an aftermarket rx made by Hitec for Airtronics or an FMA rx made for Airtronics.