Review: BetaFPV SuperG Nano Transmitter Module – Leading the Charge with ExpressLRS Gemini Support

The BetaFPV SuperG is the world’s first ExpressLRS transmitter module to support the latest Gemini Mode, promising improved connectivity and reliability of your radio link, even in challenging environments. In this review, will will discuss its features, functionality, and performance, and whether you will benefit from this innovative product.

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What’s Gemini Mode?

Gemini Mode, the latest addition to ExpressLRS, takes FPV radio communication to another level. By leveraging two antennas on the transmitter module, it simultaneously sends commands across different frequencies. This dual-channel approach dramatically reduces interference-induced packet loss, guaranteeing a robust radio link even when conditions are far from ideal. To learn more check out this post: https://oscarliang.com/expresslrs-gemini/

Gemini is not exclusive to BetaFPV, they just happened to be the first manufacturer that makes compatible hardware for this exciting new feature. At the time of writing, they offer the SuperG transmitting module (in this review), and SuperD / SuperP receivers that support Gemini Mode.

Where to Buy?

You can get the BetaFPV SuperG Nano module from:

• BetaFPV: https://oscarliang.com/product-87zs
• AliExpress: https://s.click.aliexpress.com/e/_DD7Cmlv
• RDQ: https://oscarliang.com/product-faza

It’s available in three different colors: black, red, and grey, allowing users some degree of personalization.

It comes with a JR module bay adapter, allowing it to fit into full-sized radios, a USB cable for firmware flashing, a power cable for connecting an external battery, JST to servo cable for older radios, and two linearly polarized dipole antennas.

Specification

• Antenna Connector: 2* RP-SMA
• RF Power: 25mw/50mW/100mW/250mW/500mW/1000mW
• Packet Rate: 50Hz/100Hz/150Hz/250Hz/333Hz/500Hz/D250/D500/F500/F1000
• Frequency Band: 2.4GHz ISM
• Backpack: support
• Input Voltage: 7V~13V DC
• Rated Current: 8V,1000mA@1000mW, 1:128, Gemini mode
• USB Port: Type-C
• Fan Voltage: 5V
• Default Firmware Version: ExpressLRS V3.3.0
• Target Name: BETAFPV SuperG Nano 2.4GHz TX
• Weight: 44.8g

Design and Build Quality

BetaFPV’s SuperG Nano Module has a unique design and looks different from their previous offerings, and I must say, it’s a refreshing change. This module feels like a step up in terms of build quality compared to their past releases.

The SuperG boasts a sturdy and sleek design thanks to its CNC-machined aluminium alloy case. There’s a built-in cooling fan in the center of the unit, given that the dual transmitters can generate substantial heat.

Weighing a mere 44g, this “nano” module is not only compact but also densely packed with features. It’s genuinely commendable how BetaFPV has seamlessly integrated two 1W RF chips in this small form factor, and still ensured optimal cooling.

The two customizable buttons and the RGB LED light, which signifies the module’s status, are thoughtful additions that enhance user experience. There are blue LEDs beneath each antenna indicating their operational status.

The SuperG is equipped with two RP-SMA antenna connectors.

There’s a USB-C port on the bottom for firmware updates and external power supply.

Compatibility

The SuperG module has been developed collaboratively by BetaFPV and ExpressLRS developers. Such collaboration offers a degree of assurance regarding the quality and reliability of the product. Users can be confident that this module will be supported in the ExpressLRS configurator, avoiding potential pitfalls related to compatibility and support.

This module fits directly into radios with lite module bay (also known as nano module bay), such as the Radiomaster Zorro, Pocket and Jumper T-Lite.

If you have a bigger radio with JR bay, such as the Radiomaster Boxer and TX16S, you can use the included module adapter. The thoughtful inclusion of a JST connector accommodates older style radios without a module bay, showcasing BetaFPV’s attention to diverse user needs.

Custom Buttons

There are 2 ways to use the buttons: long-press and short-press. The duration of a long press can be customized, while the number of presses for a short press can also be customized.

Default button actions:

To customize the buttons

1. Put the transmitter module in WiFi mode (wait for 60 seconds or use the ExpressLRS LUA script).
2. On your Smartphone or Laptop, join the ExpressLRS WiFi network (WiFi name: ExpressLRS TX, WiFi password: expresslrs).
3. Open a web browser and go to this address to configure your transmitter module: http://10.0.0.1
4. Go to the custom button settings page, In the button’s Action column, select the desired function. Then, choose the button type and the number of presses or duration in the Press and Count columns.
5. Click SAVE to complete the configuration.

There are 6 available functions that can be assigned to shortcut buttons:

1. VTX Setting
2. Increase Output Power
3. Enable WiFi
4. Enter VTX Channel
5. Enter Binding Mode
6. Enter VTX Band

How to Enable Gemini Mode

To change settings, you need to use the LUA script in the radio. It allows users to adjust settings such as packet rate, telemetry ratio, antenna mode, and power levels. The ExpressLRS LUA script is located in the TOOLS page: Press the SYS button, then find the TOOLS page by pressing the PAGE button.

To enable Gemini mode, you need to select Gemini in Antenna mode.

You also need to go into Other Devices, select your receiver, and select Gemini in RX Mode.

Performance

Not only the SuperG has two transmit chains and supports Gemini, each antenna can deliver up to 1W of output power. Imagine having not one, but two 1W transmitting modules packed inside a single unit. That’s precisely what you get with the SuperG!

Let’s dive into the numbers. Here’s a breakdown of the power output from both antennas across different power levels:

These measurements were taken using the ImmersionRC Power meter V2. It’s important to note that this power meter is not the most accurate tool, these measurements do not reflect the hardware quality, but rather the consistency and performance of the internal module.

After running the SuperG at its maximum 1W output power for 20 minutes, Ant 1 (right antenna) settled around 1110mW while Ant 2 (left antenna) settled around 1070mW, both readings surpassed 1W which is great.

And here’s the kicker: despite this powerhouse performance, the SuperG remained relatively cool to the touch. After 20 minutes at its maximum power, the unit was just warm. This is a testament to the effectiveness of its cooling design.

Power Concern

When I first began testing the SuperG, my primary concern revolved around its power consumption, especially in Gemini mode. Given that it effectively runs two TX modules at the same time, the current draw understandably doubles. This could lead to notable voltage sag and deplete battery life more rapidly.

While testing, I observed a 0.5V drop in voltage (I was using a 2S Li-ion battery pack) when the SuperG module was set to 1W and in Gemini Mode. That’s a significant voltage dip and something users should be aware of. To avoid this, you could power the module with an external 2S or 3s LiPo battery using the provided USB-C to XT30 cable.

Is the SuperG for You?

When I consider who might benefit the most from the SuperG module with its Gemini capability, it really comes down to the flying environment and pilot needs. If you fly alone and mainly in open fields with minimal interference and obstacles, traditional modules would most likely meet your requirements. The transition to a Gemini-equipped module such as the SuperG might not make a noticeable difference.

However, the confidence that comes with flying the SuperG is undeniable as Gemini mode offers more consistent link quality than the traditional method, reducing the chances of jitters or even failsafe. In those tricky areas swarming with interference – think busy urban zones with lots of WiFi signals or situations where multiple drones are in operation simultaneously – the SuperG’s Gemini system shines.

The SuperG is useful for:

1. Racers who demand consistent, jitter-free control.
2. Urban Flyers who navigate areas brimming with interference, like cityscapes dense with WiFi signals, or events where multiple drones are in action.

A Closer Look Inside

The module can be taken apart quite easily.

I like the cooling design a lot. The air comes in from the fan, through a channel, then the CPU-cooler style heatsink and goes out at the top, ensuring efficient heat management.

Final Thoughts

With ExpressLRS being open-source and largely hardware-independent, innovations like Gemini is likely to become standard in the near future. The BetaFPV SuperG, being the first TX module to support this new feature, offers compact and thoughtful design, coupled with great build quality.

You can get the BetaFPV SuperG Nano module from:

• BetaFPV: https://oscarliang.com/product-87zs
• AliExpress: https://s.click.aliexpress.com/e/_DD7Cmlv
• RDQ: https://oscarliang.com/product-faza

This new technology is truly an exciting advancement for fast racers seeking ultimate reliability under all conditions and is equally beneficial for other setups such as freestyle, long range and cinematic pilots.