What’s the Difference between the FrSky receivers and what do they do?
There are a number of different FrSky receivers and they are rather confusingly named, here is a run down of all the different types we use for race quads.
This is a medium sized receiver that can do both S.PORT Telemetry and SBUS at full range. It sends an RSSI signal back to your transmitter, so you know when you are running out of range.
This was made as a replacement for the X4R-SB, it is slightly smaller and lighter and is functionally identical to the X4R-SB. However this receiver uses a slightly smaller antenna than the X4R-SB, this has resulted in shorter range for some users. In addition they use a JST Connector, which is fiddly and uses plastic insulated wires (ugh!)
This receiver is can do the full range as well as SBUS like the receivers listed above, the main difference however it that it does NOT do telemetry and is also significantly smaller than the above receivers. However there is a pad for you to get RSSI data from on the receiver, so you can display it on an OSD.
This is slightly lighter than the XM+, although it is not fully range, and only has one antenna (no diversity). Again there is no telemetry but there is a RSSI output on the receiver for use with an OSD.
This is the most popular of all the FrSky Recievers, it has become a work horse of the hobby, it is identically sized to the X4R-SB, however it can only do regular telemetry (not Sport) and can only output PPM (not SBUS). This makes it almost defunct in our part of the hobby, as PPM is significantly worse than SBUS.