Happymodel ES24TX and EX900TX radio transmitter modules
These are the first ExpressLRS transmitters in the market manufactured by Happymodel. ES24TX is 2.4GHz band ExpressLRS transmitter and ES900TX is for 900MHz band. ES900TX module is capable up to 1W of the output power and comes with a 2006 sized cooling Fan, which turns on automatically when the TX power is 250mW and more. The ES24TX module is capable of outputting up to 250mW of the RF power.
Downsides – USB connector is internal and you need to open the case to access it.
ES900TX: Specifications: MCU: ESP32+ESP8285 Dimension: 55mm*39mm*11mm Weight: 9.2gram (only the TX module) Antenna connector: SMA VCC input: 5~13v, Recommend 5v~9v Minimum receiver refresh rate: 25Hz Maximum receive refresh rate: 250Hz RF Frequency optional: 915MHz or 868MHz (EU) (antenna is different size) Maximum Output Power: <33dBm (For >27dBm operation, we recommend add a fan for force cooling) (actually up to 1W)
ES900TX Specifications: Regulatory Domain: ISM2400 MCU: ESP32 (main), ESP8285 (aux,as espbackpack) RF chip: SX1280IMLTRT JR standard 5pin socket Antenna connector: SMA Frequency Range: 2400 MHz to 2500 MHz Minimum receiver refresh rate: 50Hz Maximum receive refresh rate: 500Hz RF Output Power: 10dBm~24dBm (250mW) Power supply voltage: 5v~10v Weight: 9.5 gram(without antenna） Dimension: 55.5mm*39.5mm*8mm Antenna gain: 1.87dBi
Happymodel ES24TX Pro radio transmitter module
Updated Happymodel ES24TX module with up to 1W of transmitting power. It has heatsink, cooling fan and RBG led. However USB connector still cannot be accessed from outside. Has additional ESP chip for backpack functions (telemetry relay, etc).
Specifications: Name: Happymodel ES24TX Pro Micro TX Module Regulatory Domain: ISM2400 MCU: ESP32 (main), ESP8285 (aux, as esp backpack) RF chip: SX1281IMLTRT JR standard 5pin socket Frequency Range: 2400 MHz to 2500 MHz Maximum receive refresh rate: 500Hz Minimum receiver refresh rate: 50Hz RF Output Power: >30dBm Power supply voltage: 5v~10v Weight: 51gram (without antenna） Dimension: 70*49*32.5 mm Antenna gain: 4.18dBi Firmware target: HappyModel_ES24TX_Pro_Series_2400_TX
Happymodel ES900RX (900MHz) and PP, EP1, EP2 (2.4GHz) receivers
ES900RX is the updated version of the ES915RX, the ExpressLRS receiver for 900 MHz band. Happymodel changed the main MCU from STM to the ESP8285, and now it has Wi-Fi upgrade capability.
PP, EP1 and EP2 2.4GHz ExpressLRS receivers were also the first 2.4GHz RX in the market. And they are still the most popular ones.
PP receiver has STM MCU and is not capable of the Wi-Fi update. The EP1 and EP2 receivers are ESP8285 MCU based and can be updated via Wi-Fi connection.
PP and EP2 receivers have unique ceramic antenna on board. They are the smallest Long Range receivers by size and weight including the antenna. ExpressLRS range is so great, that small ceramic antenna is enough to have stable decent range (several kilometers).
ES900RX receiver specifications: MCU: ESP8285 VCC input: 5v Operation current: ~100Ma Rx To FC protocol: CRSF RF Frequency optional: 915mhz or 868mhz(EU) Dimension: 12mm*12mm*3mm Weight: 0.60 gram (exclude antenna) Antenna connector: IPEX1 Telemetry output Power: <17dBm
PP, EP1, EP2 receiver specifications: PP MCU: STM32, EP1, EP2 MCU: ESP8285 MCU SX1280IMLTRT RF Module PP, EP2 : On board SMD ceramic antenna, EP1 : Omnidirectional antenna with IPEX connector Frequency Range: 2400 MHz to 2500 MHz Minimum receiver refresh rate: 50Hz Maximum receive refresh rate: 500Hz Rx To FC protocol: CRSF Working voltage: 5v Weight: 0.42g (without antenna) Dimension: 10mm*10mm*3mm Peak gain: 2.23dB Range: 3KM above (Open Area)
The difference between PP, EP1 and EP2 receivers
PP vs EP1 vs EP2
PP (with SMD antenna)
EP1 (w/o antenna)
EP2 (with SMD antenna)
Happymodel ES24TX Slim Pro TX radio transmitter module
Happymodel ES24TX Slim Pro is the JR Lite type ExpressLRS module. Fits TBS Tango, FrSky X-Lite and other “Lite” module bay transmitters. It has all metal case, acting as a cooling heatsink and a fan, starting to blow at the 250mW. is capable of delivering 1W of the RF power. It is the most powerful 2.4GHz ExpressLRS transmitter module in the market.
The first batch of the ES24TX Slim Pro had the Telemetry Lost issues. This could be fixed by some soldering and changing the components on the mainboard. Happymodel offers free repair service as well. All the modules, shipped after the 2021-09 should not have this issue.
Specifications: Packet refresh rate: 25Hz/50Hz/100Hz/200Hz (915MHz/868MHz) 50Hz/150Hz/250Hz/500Hz (2.4GHz) RF output power: 100mW/250mW/500mW Frequency bands (Nano RF Module 2.4G version): 2.4GHz ISM Frequency bands (Nano RF Module 915MHz/868MHz version): 915MHz FCC/868MHz EU Input voltage: 5V~12V USB port: Type-C
BetaFPV MicroTX radio transmitter modules
BetaFPV ExpressLRS Micro TX modules are full size (or so called micro) JR type. BetaFPV Micro TX module has OLED screen and 5-way menu navigation joystick. They are capable of outputting up to 500mW of RF power. Module available in FCC (/EU (
Specification Weight: 0.7g (receiver only, w/o antenna) Size: 12mm*19mm Telemetry power: 20dbm (100mW, 2.4G Version) Frequency bands (Nano receiver 2.4G version): 2.4GHz ISM Frequency bands (Nano receiver 915MHz/868MHz version): 915MHz FCC/868MHz EU Input voltage: 5V Antenna connector: IPEX MHF
BetaFPV Lite 2.4GHzExpressLRS receiver
The smallest ExpressLRS receivers in the market.
BetaFPV Lite receiver with “Tower” type SMD antenna.
BetaFPV Lite receiver with “Flat” type SMD antenna.
BetaFPV ELRS Lite receiver with “Tower” and “Flat” antenna comparison table:
Range (TX 100mW 150Hz)
About 600m (?)
Both “Tower” and “Flat” antennas have almost the same performance in gain, but the efficiency for “flat” antenna is better than “tower” antenna. However this is only the specs on the paper. In the reality the tower antenna performs better and the range is greater. Need to be noted that receiver with the “flat” type antenna has the LED on the top side of the PCB for the better visibility.
Specifications: PWM channel: 5 channels Serial output protocol: PWM or CRSF MCU: ESP8285/SX1280/SX1281 Telemetry power: 12.5dbm/17mW Frequency bands: 2.4GHz ISM Input voltage: 5V~9V DC @ “+” pad Default firmware version: ExpressLRS v2.0 Antenna: IPEX MHF + T antenna (recommend 80mm Dipole T Antenna) Adapted RC Model Type: Multirotors, Fixed-wing aircraft, Helicopters, RC Cars, RC Boats and etc. Size: 19mm*32mm*9mm (without antenna) Weight: 4.5g (with antenna)
Namimno Flash and Voyager TX ExpressLRS transmitter modules
Namimno Flash is 2.4GHz and Voyager is 868/915MHz band ExpressLRS transmitter modules. These TX modules are based on STM32F103 MCU, so they have different Wi-Fi update method, must be flashed via the backpack Wi-Fi chip. Namimno Flash max RF power output is 250mW and Voyager is 1W.
Namimno 2.4GHz Flash Nano Receiver specifications: Frequency: 2400-2480MHz Transmitting power: <12.5dBm Remote control distance: >3000m Remote control refresh rate: 50Hz-500Hz RF interface: IPEX connector Power supply: 4.5-10V Size: 18.35*11.5*3.5mm
Namimno 915MHz Voyager Receiver specifications: Frequency: 868-915MHz Transmitting power: <17dBm Remote control distance: >3000m Remote control refresh rate: 25Hz-250Hz RF interface: IPEX connector Power supply: 4.5-10V Size: 18.35*11.5*3.5mm
HGLRC Hermes 2400TX ExpressLRS transmitter module
HGLRC Hermes 2400TX is the 2.4GHz band ExpressLRS transmitter module. Fits the standard JR module bay. Comes with the simple dipole t-style antenna. Module has USB Type-C socket for firmware updates and XT30 socket for external power supply (up to 17 volts or 4S battery), which is absolutely not needed in my opinion.
The first batches have been known to have short Wi-Fi range, due to the missing internal antenna on the PCB.
Another issue is the HLGRC failed to implement the USB reset circuit correctly. You have to hold down the boot button there before you plug the module with the USB cable. You can access the button from the hole in the back of the case (which is super inconvenient).
Flywoo ExpressLRS receivers are based on the common DIY ExpressLRS reference design. For upgrading the firmware you should select the DIY_2400_RX_ESP8285_SX1280… firmware option.
Flywoo EL24E receiver has SMD Ceramic antenna. and the weight if the receiver is 0.4 grams withantenna. Flywoo EL24P receiver has uFL (ipex) connector for supplied dipole antenna and weight twice as much.
Specifications: Frequency band: 915MHz FCC (AU EU updates the firmware by itself) Chip type: ESP8285 MCU RF chip: SX1276 Frequency range: 915MHZ Maximum receiving refresh rate: 250HZ Minimum receiving refresh rate: 25HZ Working voltage: 5V Weight: 0.6g Working Agreement: CRSF (Betaflight) Size: 11mm*18mm*3mm Antenna plug: IPEX MHF
Mateksystems ELRS-R24-D and ELRS-R24-S receivers
Matek also released The ELRS-R24-D and ELRS-R24-S receivers are bigger than other manufacturers versions because of the one side component placement design. Industry first: Matek ELRS-R24-D is the first ExpressLRS receiver with antenna diversity feature and the ELRS-R24-S is the first ExpressLRS receivers with the SMD antenna and Low noise power amplifier.
Matek ELRS-R24-D has PA/PNA amplifier and can output the telemetry back with up to 23dBm of RF power.
Matek ELRS-R24-D also has PA/PNA amplifier, but the power output is 20dBm.
Power dissipation: 40~45mA(before binding), 70~75mA(binding), 90~95mA(wifi mode)
PCB size: 21mm x 15mm
Weight: 3g w/ 2x antennas
Packing: 1x ELRS-R24-D, 2x IPEX MHF1 Antennas
molex 479480001 SMT antenna
RF Frequency: 2.4GHz ISM
Telemetry power: 20dbm (100mW)
Receiver protocol: CRSF
Input voltage: 4~9V DC @ 5V pad
Power dissipation: 40~45mA(before binding), 60~65mA(binding), 90~95mA(wifi mode)
PCB size: 21mm x 15mm
Packing: 1x ELRS-R24-S
Mateksystems ELRS-R24-P PWM receiver
Another industry first – first ExpressLRS receiver with PWM output on one board. Outputs 5 PWM channels. This receiver does not have the PA/LNA and its telemetry power output is only 12dBm, but it is more than enough for LOS fixed wings. Comes only 2.4GHz band option.
Comparison in MATEK ELRS-R24 series
2x IPEX MHF1， Diversity
CRSF Serial receiver
Comparison between Matek ELRS-R24-P and CRSF-PWM converter
Receiver with ELRS direct PWM output
CRSF to PWM Converter/Decoder
compatible with any CRSF protocol receivers (including 433MHz, 868MHz, 915MHz, 2.4GHz)
Specifications: XT30 port: 7V~21V, DOES NOT support 6S or above battery voltage RF output power: 25mW/50mW/100mW/250mW/500mW/1000mW Packet refresh rate: 50Hz/150Hz/250Hz/500Hz Storage Box Size: 29x29x15.5mm Frequency band: 2.4GHz ISM Weight (Including JR): ~105g Automatic and active cooling Dimensions: 87x55x15mm Input voltage: 5V~12V Wi-Fi update capable USB port: Type-C
Ironically FrSky also decided to take a part in the ELRS market and released their co-brand VANTAC ELRS TX module. It is nano sized (JR Lite) transmitter module in the same case as VANTAC Multiprotocol module. This is the cheapest ELRS Nano TX module in the market. No more details at this time.
Specifications: Model: AION ELRS 2.4TX-NANO Main control chip: ESP32 Transmitting power: 10-500mw Frequency bandwidth: 2.4GHz-2.5GHz Compatible firmware: ELRS Antenna: omnidirectional high gain diamond antenna Quick socket: NANO (JR lite) interface Working voltage: DC5-8.4V Maximum refresh rate: 500Hz Screen form: 0.96 inch white light OLED Screen resolution: 128*64 Menu button: five-way joystick Upgrade method: UBC-C or Bluetooth Simulator: supports Bluetooth and WIFI wireless mode
iFlight ELRS receiver
ELRS receiver with PA/LNA chip. Telemetry output – 17dbm (868/915MHz) / 20dbm（2.4G). This receiver has non standard pinout and comes with SH1.25 connector pre-soldered. It is Plug and Play compatible with with iFlight flight controllers. Available in 868/915MHz or 2.4GHz bands. 2.4GHz receiver also available in SMD antenna or regular antenna with u.Fl connector.
ExpressLRS receiver with PA/LNA (amplifier) and diversity antenna (antenna switching) features. PA/LNA chip SE2431Lfrom Skyworks has low noise amplifier and antenna switching capability. It has the highest telemetry power output 250mW for ExpressLRS receiver.
DarwinFPV is preparing to release the ExpressLRS receiver.
HappyModel Moxon 2.4G 4.18DBI Antenna
Happymodel Moxon Antenna is a folded dipole and single folded reflector type antenna. This antenna is the same as BetaFPV and Namimno 2.4GHz Moxon antennas. Currently the cheapest 2.4GHz Moxon type antenna.
Specifications: Item Name: Namimno Black Pearl Loop Antenna Package Weight: 30g Color: Black Wireless frequency: 2350-2550MHz Gain: 2.8dB RF interface: SMA Male Size: 47.65*64mm
Prodrone 2.4GHz moxon antenna
Probably the best Moxon type antenna for 2.4GHz ExpressLRS link. Gain of this Moxon antenna is about 5.5dBi. Each of this antenna is hand made and SWR is tested by lab equipment. It even comes with the test results labeled!
Specifications: Bandwidth: 2400-2480 MHz Beam width: over 180 degrees Gain: 5.5 dBi Cable length: ~7cm Antenna conductor: 1mm silver covered pure copper vSWR: lower than 1.3 Maximum power input: 50W Connector: SMA or RP-SMA Weight of antenna: ~6g
BetaFPV Dipole T-antenna for receiver
This is the best dipole antenna for the ELRS receiver. Antenna elements are made from the steel wire and does not bend easily. Antenna housing has notch for ziptying it to the quadcopter frame. Small, but important detail.