Jumper T20 ELRS Gemini

Jumper T20 Gemini  is the highest of the T20 series. It is a quality transmitter with EdgeTX firmware and 1W ELRS Gemini module. The Jumper T20 is the ideal choice for those looking for a small transmitter without compromise. The radio is noticeably smaller than the Radiomaster Boxer or TX16. However, even at this size, it uses large RDC90 gimbals. As with the larger radios, the Jumper T20 Gemini will provide 6 switches, 6 potentiometers. There are six adjustable buttons. There are also joysticks on the radio for trim settings, but these can be reconfigured and used as additional switches. For ease of transport, it has a folding swivel double antenna. All information is displayed on a 1.3" OLED display. A great advantage is the integrated memory that replaces the classic SD card, which greatly increases the reliability of the radio.

Aluminum heat sink with a fan for cooling the Gemini ELRS module is on the back of the transmitter. The Jumper T20 is powered by two Liion batteries (not included). The transmitter has a shaft for the larger 21700 which will noticeably extend the battery life. The batteries are conveniently charged via the USB-C connector.

The big advantage of the radio is the aforementioned integrated ELRS Gemini module with a power output of up to 1000mW and a refresh rate of up to 1kHz. The Gemini module includes two transmit chips and two antennas in one, which will excel when combined with full diversity receivers (those that include two receive chips). In Gemini mode, the ELRS transmits and receives on two channels simultaneously. As a result, Gemini will offer more reliable RC transmission more resistant to interference and more stable LQ. 

The ExpressLRS (abbreviated ELRS) is an open source project and the transmit and receive modules are produced by multiple manufacturers. ELRS is currently one of the most advanced RC transmissions. It offers reliable long distance link, high refresh rate, adjustable power, update via wifi and more. ELRS at 2.4GHz outperforms conventional RC systems in every way while maintaining short antennas.  

The Jumper T20 Gemini uses the more premium RDC90 gimbals, as does the Jumer T20S. 

reviews by OscarLiang