The Speedybee TX500 is a video transmitter you can mount in a 20x20mm FC stack. It also has built-in mic, VTX control and some other features that you might want to consider.
Further Reading: Learn more about 5.8GHz video transmitters.
Where To Buy?
- Amazon: https://amzn.to/2S9qNwO
What’s in the Box?
- TX500 VTX
- MMCX antenna
- MMCX to SMA Pigtail
- 1.0mm 6pin Cable
- a set of M2 nylon standoffs and nuts
An awesome set of accessories!
Features and Specs
Here is the basic spec of the VTX500:
- Channel: 5.8GHz, 6 Bands, 48 Channels
- Selectable Output Power Levels: 25mW, 200mW/, 500mW
- Working Current: 5V@150mA~550mA
- Voltage out to FPV camera: 5V@max 250mA
- Input Voltage: 3.5V – 5.5V (Supports 1S LiPo)
- Built-in Microphone for Audio
- MMCX Antenna Connector
- Weight: 4g (without antenna)
- Dimension: 28 x 28mm, Mounting holes pattern 20x20mm M2
Just based on the spec, this looks to be perfect for micro quads, and ultra-light racing drones that use flight controllers with 20x20mm mounting holes. It has almost all the bells and whistles you’d need on a quad.
The TX500 VTX supports Tramp VTX Control (In Ports tab, Peripherals, select IRC Tramp, not SmartAudio) as well as Pitmode. This allows you to change VTX channel and power in Betaflight OSD, and stops the VTX from transmitting with a switch on the radio when you crashed.
You have solder pads as well as JST pin header for connection.
On a micro quad or racing drone, you would most likely be using a micro FPV camera that doesn’t have a microphone. The onboard mic on the TX500 is an excellent addition and saves you from all the troubles of installing an external mic if you want to listen to the motors when flying.
VTX is Locked!
One thing to take note of is that the VTX is locked out of the box. Output power is limited to 25mW and many bands and channels are disabled due to regulations in many countries.
However, you can unlock it by simply holding down the button for 10 seconds.
Connection and Usage
Once you get used to looking at the LED panels, and know what you are doing, the TX500 is pretty easy to use.
Only complain I have is the 3.5 to 5.5V input voltage. It’s cool that it can be powered by an 1S battery, but most of us will be using this on higher cell count batteries. It is limited to 5V, so you will need quite a beefy 5V BEC for video transmitter (draws up to 0.55A at 5V).
Power Testing
| R1 | R2 | R3 | R4 | R5 | R6 | R7 | R8 | |
| Pitmode | < 0.1 | |||||||
| 25mW | 21.5 | 21.2 | 21.5 | 22.9 | 21.1 | 22.1 | 21.7 | 19.6 |
| 200mW | 295 | 309 | 313 | 325 | ||||
| 500mW | 505 | 550 | 522 | 490 |
The output power seems pretty good too! All channels on 25mW seem to be within spec. 200mW level outputs considerably more, but I really don’t think that’s a huge problem at all as long as it’s not a proper race.