Random rx loss on crossfire


I recently been experiencing random rx loss during flight. It’s a x220s that I have installed Crossfire Nano RX in the past. I have been flying for a while now without issues. Recently I have been getting rx loss randomly during flight and I’m not that far out. I switched out a new nano receiver and it seemed to fly well the next few time of flying. But today I started experiencing the random rx loss again. I have an immortal t antenna that is still in good condition and in the position I always had. I checked all soldering connections and they are all still good and solid. I use x9d radio with tbs micro tx add on and has been the same too. Antenna connector to the rx is good too
Last edited:


Participation Award Recipient
Did you check your frequency settings? if you have the wrong band set, you can collide with other radio stuff and get random signal issues at short ranges.

beyond that, we have standard signal troubleshooting to do. Have you done a range check (does Crossfire have a range check mode that drops the power, so you can do basic range checks at ~30m instead of full distance)


These are my micro tbs cf tx settings that I have been using from the beginning and have excellent range before. I have other quads running. Crossfire and they all have normal range. It’s only my x220 wizard that is getting the random rx loss.

How do I use the range check mode on micro tx module?


Old and Bold RC PILOT
You may have a few different causes but when using ISM band (Digital radio) transmitters for RC purposes there is a requirement for the transmitter to use collision avoidance. The transmitter must check to see if the frequency to be used is not already being used before it transmits. If the frequency is already in use the transmitter must wait until the frequency is clear before transmitting. Sometimes this might mean that it cannot transmit of the chosen channel before it moves to the next required channel to start the whole check for clear frequency thing all over again.

It is possible for a transmitter to be right next to the receiver and a LOS still occur due to spectral congestion, (lack of clear channel). 915 MHz can have a reasonably long range especially where all other persons also use the MAXIMUM transmitter power setting rather than dynamic, (Tx power reduced to what is required to maintain connection.

Another source can even be persons in the pit area leaving their transmitters powered on and using the same band even though they are not using the transmitter to fly a model or drone. Each source of transmission reduces spectrum availability.

Just my bleating!

Have fun!