Very interesting! Thanks for the great response.

Is there a better frequency available to amateur hardware that would give tolerance within more reasonable limits?

Without a shared external clock reference, i.e. over longer distances, how expensive does the hardware get if you want to be able to accurately measure the time/phase wandering to correct in software?

Just curious if it’s a limit of the low cost RTL-SDR or if it’s a harder problem than that (or both?).