I've reversed the throttle (which I do for all electric motors) and plugged the rx battery in at full throttle, bur no beeps and no motor. The system works fine on brushless motors - it is just brushed motors that I can't get to work. I tried the Spectrum again and after 2 throttle movements the motor ran. I have 3 escs and they all do the same (I don't recall 2 of these beeping in the past, but they ran motors. The third esc is new to me, and as it didn't work I tried 2 others and a motor that I happened to have lying around.
Thanks Andy,
Colin