RadioMaster ER6 2.4GHz ELRS PWM Receiver

The RadioMaster ER6 is an ExpressLRS receiver for 2.4 GHz with six PWM outputs and two antennas, intended for fixed-wing aircraft and other models with servos. RadioMaster is based in Hong Kong. The classification as fixed-wing follows from the PWM outputs. Unlike the nano receivers for FPV drones, the ER6 drives servos and speed controllers directly and needs no flight controller as an intermediate stage.

The receiver weighs 14.5 g and has six PWM channels. It works from 4.5 to 8.4 V, so it can sit on usual receiver supply circuits or on a 2S LiPo, as long as the connected servos tolerate the same voltage. It sends telemetry at up to 100 mW, adjustable via a LUA script; this reports signal strength and battery voltage to the radio. The packet rate sets the spacing between two control packets: 50 Hz is 20 ms, 150 Hz is 6.67 ms, 250 Hz is 4 ms and 500 Hz is 2 ms. That is a packet interval and not end-to-end latency.

In the EU the limit in the 2.4 GHz band without a licence is 100 mW EIRP; the 100 mW of telemetry sits at that limit, and antenna gain counts too. 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.

When choosing, the failsafe matters most: on signal loss the servos move to the positions set in the receiver, and on a fixed-wing aircraft that setting decides how the model behaves. The two antennas should sit in the fuselage pointing in different directions, not next to carbon fibre or the battery. Servo plugs and the pin headers of the PWM outputs wear from frequent plugging.