Over two years ago, BetaFPV introduced their Nano TX ExpressLRS module to the world, and they’ve just launched the second generation, boasting significant improvements over the original. Does the BetaFPV Nano TX V2 ELRS module stand up to the hype, and how it compares to other nano-sized ExpressLRS modules? Let’s find out in this review.
Learn more about radio transmitters in FPV: https://oscarliang.com/radio-transmitter/
Learn more about ExpressLRS here: https://oscarliang.com/setup-expresslrs-2-4ghz/
Where to Buy?
You can purchase the BetaFPV Nano TX V2 module from:
The BetaFPV Nano TX V2 comes in three frequency options: 2.4GHz, 868MHz, and 915MHz. My review focuses on the 2.4GHz version, as it’s my frequency of choice for the control link.
Specifications and Features
- Antenna Connector: RP-SMA (2.4GHz), SMA (915/868MHz)
- RF Power (2.4GHz): Up to 1W
- RF Power (915/868MHz): Up to 2W
- Packet Rate (2.4GHz): Up to 1000Hz
- Packet Rate (915/868MHz): Up to 200Hz
- Frequency Band: 2.4GHz ISM, 915MHz FCC, 868MHz EU
- Input Voltage: 7V~13V DC
- Power Consumption: Varies by frequency and power
- USB Port: Type-C
- Fan Voltage: 5V
- Default Firmware: ExpressLRS V3.3.0
- Weight: 28g
The Nano TX V2 features an integrated TCXO (Temperature-compensated crystal oscillator) to minimize frequency deviation due to temperature differences for stable performance, and also handle better with signal interference with other devices such as the VTX.
The V2 module supports ExpressLRS Backpack, which means you could configure it to do cool stuff like changing your analog goggle’s channel using your radio.
Here’s a comparative overview between the new Nano TX V2 and the previous version.
| Nano TX V2 | Nano TX V1 | |
| Max RF Power | 1W (2.4GHz) 2W (915/868MHz) |
500mW |
| RF Chip | SX128X/SX1276 | SX128X/SX1276 |
| Antenna T-LED | Supported | Unsupported |
| Cooling Fan | Yes | No |
| ELRS Backpack | Supported | Unsupported |
| External Power Supply | Supported (7-13V) | Unsupported |
Closer Look
The Nano TX V2 maintains a similar aesthetic to its predecessor, featuring a white, injection-molded plastic shell and a lightweight build at just 28 grams.
A USB Type-C port beneath the module facilitates firmware updates and external power connectivity.
For high RF power demands that certain older radios cannot meet, an external power source (7-13V) can be connected using the provided USB-C to XT30 cable. My tests with the Radiomaster Boxer and Pocket showed that external power isn’t needed for operating at 1W, though it’s also a useful option for those experiencing battery voltage sag at high outputs.
The 2.4GHz module uses an RP-SMA antenna connector, while the 868/915MHz versions are equipped with SMA connectors.
Two customizable buttons on the module allow for easy access to functions like Bind Mode, RF Power adjustment, and VTX Settings changes etc.
With the increased transmission power, the Nano TX V2 includes a built-in cooling fan, automatically activated at 250mW or higher by default. Although effective in keeping the module cool, the fan is noticeably loud, measured around 48dB from a meter away.
T-LED Antenna
The Nano TX V2 introduces a first-ever feature: the “T-LED” antenna—a T antenna with an integrated LED light. It’s intended for pilots to visually monitor their signal during flight, with the LED flickering to indicate data transmission and reception. The flickering speed varies based on the telemetry ratio and packet rate. The T-LED antenna offers a 2dBi gain, and you could put standard (non-LED) antennas on the Nano TX V2 too.
However, in my experience, the practicality of the T-LED antenna is somewhat limited. Under daylight conditions, I could hardly see the LED light, and at high packet rates, the rapid flickering makes it appear constantly lit, reducing its effectiveness as a signal indicator.
BetaFPV Nano TX V2 compatibility
The Nano TX V2 seamlessly fits into radios with “Lite” external module bays, like the Radiomaster Pocket that I used.
For those with standard JR module bays (e.g., TX16S, Boxer, and Jumper T20S), an adapter is available to accommodate the BetaFPV Nano TX V2 module, ensuring broad compatibility across various transmitter models.
Get the adapter here:
Power Consumption
Power consumption of the module varies with the RF power level, increasing significantly at 250mW and above, primarily due to the cooling fan kicking in.
Here’s a breakdown of the current draw and actual RF output measured with an ImmersionRC Powermeter V2 across different power levels:
| Power Levels | RF Power | Current |
|---|---|---|
| 25mW | 26mW | 0.19A |
| 50mW | 58mW | 0.22A |
| 100mW | 106mW | 0.3A |
| 250mW | 290mW | 0.5A |
| 500mW | 533mW | 0.62A |
| 1000mW | 1230mW | 0.85A |
Output Power Testing
Before conducting the output power testing, I updated the Nano TX V2 to the latest ExpressLRS firmware version 3.3.2. When compared to the Radiomaster Ranger Nano module, the BetaFPV demonstrated superior RF output power, initially exceeding 1.3W and stabilizing around 1.16W after 20 minutes of testing, showcasing its impressive performance.
ExpressLRS Firmware Update
Updating the ExpressLRS firmware on the Nano TX V2 is straightforward.
Simply connect the module to your computer via the USB-C port, use the ExpressLRS Configurator, select the BetaFPV 2.4GHz Nano TX V2 as the device, choose UART as the method, select the appropriate COM port, and initiate the firmware flashing process.
Gemini Mode Support?
The Nano TX V2 does not support Gemini Mode.
For those interested in this feature, I recommend checking out the SuperG module, which I’ve recently reviewed. While more costly, the SuperG doesn’t necessarily offer better range but does provide improved redundancy and more consistent link quality, especially in interference-heavy environments. For pilots on a budget or those flying in areas with low RF noise, the Nano TX V2 remains a solid choice.
Conclusion
If you’re in the market for an affordable yet high-performing ExpressLRS module, the BetaFPV Nano TX V2 stands out as an excellent choice. It delivers outstanding output power alongside well-designed features that enhance the user experience. As a Lite module, and with the aid of a JR to Nano module adapter, it’s essentially compatible with radios of all sizes. My only complaint would be the noisy cooling fan, although it proves effective in maintaining the module’s temperature.
You can purchase the BetaFPV Nano TX V2 module from: