So ya wanna measure distance with 4 cheap radios & a cheap SRAM to measure propagation delay. Before investing in a full system, let's try it with a laser reflection & a Rigol.

A cheap radio would have automatic gain control & might have less capacitance, but the problems of longer rise time with a smaller signal & erratic half way point in the waveform would probably still be too great. Maybe a very low resistance pulling down the photodiode & a very high amplification would get rid of enough capacitance.

The kind of components it would take to measure propagation delay of RF are going to be out of reach, for any human price scale. You'd think someone would invent a local area GPS system, which used a different frequency, but used the same components to have a cheap GPS system in a room.

Another idea was to hack a laser tape measure to use a radio for part of the signal propagation. The same problems of capacitance & erratic rise time would apply.


The schedule is now to convert 1 aircraft to autopilot every month, combined with several days of formalities required to run a business: symbolic meetings & symbolic traveling. It's extremely ambitious & doesn't leave any time for experimenting. At least the Blade MCX came through as a viable platform, right away, & the method of overriding the controls is proven.