Runcam is the maker of the little TX200U VTX, and they just released an even smaller VTX the TX100! This nano VTX is only 14x14mm and weighs 0.9g, possibly one of the smallest VTX on the FPV market.

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Learn about the basics of VTX in this buyer’s guide.

Where to Buy?

• Amazon: https://amzn.to/2GPW7cW
• Banggood: http://bit.ly/runcam-tx100

The VTX comes with an antenna and some silicone wires. Manual is only available online.

Specs & Features

• Selectable Output Power: 25mW and 100mW
• 37 Channels, 5 Bands (E4, E7 and E8 disabled)
• Voltage: 4.5V – 5.5V (Do NOT Power From LiPo!)
• Operation Current:  150mA – 300mA
• Supports VTX Control with Tramp protocol (enables changing settings via Betaflight OSD or LUA script)
• Single push button for changing settings
• Antenna: U.FL 2dB Omni antenna
• Weight: 0.9g without antenna and wires, antenna weighs 0.6g, VTX weighs 2.1g with included wires and antenna
• Dimension: 14 x 14mm

The Runcam TX100 Nano VTX is 1mm smaller than Eachine Nano VTX (14x15mm), and about the same as the TBS Pro32 Nano (15x13mm).

The compact size and light weight is great for small builds like tiny whoops and toothpicks. Although the maximum output is only 100mW, it should be enough for most micro quads.

Output Power Testing

Let’s verify how accurate the output power is. Measurements were taken 10 seconds after VTX power up, using the ImmersionRC Powermeter V2.

The output powers are quite accurate I have to say, very happy with the result!

One thing that I noticed is that the output power actually started off a little higher, for example for 100mW, it came on at around 110-120mW, but decreased as heat built up. It would stabilize at around 2/3 of its specified power after about a minute without any cooling. If you want optimal performance, make sure to provide adequate cooling, such as airflow during flight.

How to Use Runcam TX100 VTX

There is a tiny push button on the VTX for changing settings like power level and channel, but it’s truly tedious to use.

You have to count how many seconds you’ve been holding the button and how many times you’ve pressed it… Not to mention there are only two LED’s, good luck with counting the flashing. For instruction how to use the push button, please check manual.

To change settings, the easiest way is definitely using VTX Control, via Betaflight OSD. To do that, connect the “IRC” pin to the TX pin of a spare UART on your flight controller.

And then select IRC Tramp under Peripherals in that UART.

If you are using Betaflight 4.1 or newer, don’t forget you also have to set VTXTables properly in order to use VTX control feature. See this article if you are not sure what VTXTable is.

Enter this snippet in CLI, you are good to go!

# vtxtable vtxtable bands 5 vtxtable channels 8 vtxtable band 1 BOSCAM_A A CUSTOM 5865 5845 5825 5805 5785 5765 5745 5725 vtxtable band 2 BOSCAM_B B CUSTOM 5733 5752 5771 5790 5809 5828 5847 5866 vtxtable band 3 BOSCAM_E E CUSTOM 5705 5685 5665 0 5885 5905 0 0 vtxtable band 4 FATSHARK F CUSTOM 5740 5760 5780 5800 5820 5840 5860 5880 vtxtable band 5 RACEBAND R CUSTOM 5658 5695 5732 5769 5806 5843 5880 5917 vtxtable powerlevels 2 vtxtable powervalues 25 100 vtxtable powerlabels 25 100 save

Conclusion

At the time of writing, the Runcam TX100 Nano VTX is priced at only $15 on Banggood. At only 100mW, perhaps it’s not as powerful as the TBS Pro32 Nano, or even the Eachine Nano, but the lower price makes up for it.

You can get the TX100 from

• Banggood: http://bit.ly/runcam-tx100
• Amazon: https://amzn.to/2GPW7cW

The good

• Affordable price
• One of the smallest and lightest VTX on the market
• Supports VTX Control
• Accurate output powers

The bad

• 100mW only
• 5V input only… It would be nice if it supports 2S or even 3S LiPo input for flexibility
• Output power under performed without proper cooling
• No built-in microphone