Team BlackSheep (TBS) Crossfire Diversity Nano RX

The TBS Crossfire Diversity Nano RX from Team BlackSheep (Singapore) is a Crossfire receiver in nano format with chip-based diversity over two inputs and a connection for a backup battery. Crossfire works on 868 or 915 MHz and is built for range; the receiver is classed for mid-size multicopters that fly long distances.

It weighs 1.8 g at 24 x 18 x 5 mm and works from 3.3 to 8.4 V. The manufacturer gives the 40 km range without distinguishing FCC from CE; it is a best case with clear line of sight and altitude and, without those conditions, not comparable with other systems. Low frequencies penetrate obstacles better than 2.4 GHz and the packet rate is lower, which is why Crossfire is designed not for the shortest reaction time but for link reliability. The backup battery connection allows the receiver to be powered independently of the flight controller.

The 915 MHz version is the FCC variant; in the EU the 868 MHz band with its own power and duty-cycle limits is the one to use. Equipment may be operated in the EU only in the approved frequency ranges and power levels. In the open category visual line of sight applies, and long ranges are no selection criterion there, but they are for operations in the specific category.

When choosing, the antenna arrangement counts: both inputs need an antenna each, as far apart as possible and oriented differently, and the longer 868 MHz antennas are sensitive to kinks. The firmware of receiver and transmitter module has to match. At 1.8 g the solder pads and connectors are the wear points, and the backup battery ages on its own.