Before I make further enquiries, can anyone advise whether an extremely small transmitter in the 138-235 MHz range, mounted on the drone, is likely to interfere with either the 2.4 or 5.8 MHz of the Mavic Air or whatever frequencies the RC works on for other models?
Harmonics, in particular the intermediate frequencies may overlap. Also depends how "clean" the transmitter is generating its waveform and frequencies and filtering.
In short, try it. It might interfere, it might not.
The claim "they use different bands so its fine" simply isn't true - radios work on a serial of intermediate frequencies to step up and step down.
The mavic may well use 45 or 100MHz IFs and so on. There's also potential induction into the wires or boards themselves that could cause interference or errors.
You'll also have local oscillators and timing circuitry that could be liable to interference due to the frequencies they use.
You have to try it as there are so many variables. It likely wont interfere but its also perfectly possible it will - pay attention to things like the compass as EM induction can affect that.
