Brian wrote: This Spektrum transmitter might be considered. Wireless link for training and good value too. It has a push button momentary switch which I assume is the trainer function.
www.horizonhobby.co.uk/p/spektrum-dx6e-6...94SPMR6650EU&p=43935
The Spektrum equipment is good value for money but for longevity, reliability, and robustness; I am favouring the 'old school' manufacturers. I have had poor experiences with the individual battery cell setup of the low-end Spektrum transmitters, and the switchgear is less than robust, and (subjective and not intended for discussion on this thread) the low-end receivers we have been using seem to brown-out regularly!