The documentation is very vague about how you should set up the RF settings, by which I mean the “Air Speed”, “Max Window”, the number of channels and how much appart the channels are.
Has anyone made any tests for range and reliability or has any more information about how to correctly set these up? I somewhere read, that you shouldn´t be using more than 4 channels, but some say its ok to use much more.
Also does anyone have any experience with flying multiple UAVs, each with it´s own RFD link? I have used them with up to 3 different links, but configured the channels to be different.
I have been using RFD868X modems for years without issues so far (besides during testing with an early FW), but one does wonder how much these setting influence operations.
I would start by asking what are you expecting of range - many people are restricted to visual line of sight or maybe even using an observer. Some are licensed to longer ranges.
Air Speed has to be higher than Baud with some overhead (think of radio-to-radio overhead comms outside the mavlink stream, add more when using PPM or SBUS), I think max window goes down as baud increases (possibly).
Considering the restrictions I personally have via local regulation, it would be impossible to get the RFD900X’s out of range, and I use half power settings too (TX Power 27). In fact I’ve seen 16km at near-ground level and I have reports of much longer distances and even ridiculous data rates - admittedly unsupportable claims due to confidentiality.
I believe RFD868’s don’t necessarily have the same range as the 900’s even though they have a lower frequency, due to regional restrictions.
I think it still comes back to do your own tests for range and reliability - could be leaving the aircraft at a site and driving away in a car with the groundstation and/or transmitter, with observers at both ends.
Set and test Fence, RC link loss and RTL.