RP1 V2 ExpressLRS Nano Receiver

The receiver is a 2.2 g board that decides whether your quad answers the sticks. ExpressLRS is the open-source link that replaced every proprietary protocol in FPV, and the RP1 V2 is RadioMaster's own endpoint for it: a SEMTECH SX1281 radio driven by an ESP8285, talking CRSF to the flight controller over a single UART.

The part worth paying for here is the TCXO, a temperature-compensated crystal oscillator. Without one, the receiver's reference frequency drifts as the board heats up under a stack or chills on a winter flight, and a drifting reference is exactly what causes a link that works on the bench to fall apart at range. It is a small component that solves the failure mode beginners misdiagnose as antenna placement.

Packet rate is selectable from 25 Hz to 1000 Hz. Low rates buy sensitivity and range, high rates buy latency and stick resolution; 250 Hz is the sane freestyle default and the one to start on. Telemetry runs at 10 mW back to the radio, which is what feeds link quality, RSSI, and pack voltage into your OSD and your radio's warning beeps. The antenna is a 65 mm T dipole on a UFL connector, and its placement matters more than any setting in the configurator: get both legs out of the carbon, ideally at ninety degrees to each other.