The Video Transmitter (VTX) is a crucial component of the FPV system, wirelessly transmitting camera images to FPV goggles.
standalone VTX module
digital camera + VTX integrated alone system ?
DJI-dat - DJI-air-unit-dat - DJI-O4-dat == 100 usd - DJI-O3-dat
other info
chip solutions
1. RF / Video Transmitter Chips
| Chip / IC | Function | Notes / Typical Use |
|---|---|---|
| MAX1476 | RF Power Amplifier | Low-power analog VTX, 25–200 mW |
| MAX2606 / MAX2608 | VCO / PLL / Frequency Generator | Generates carrier frequency, used with PA |
| RFPA022 / RFPA023 | RF Power Amplifier | Popular in 600 mW–1 W micro/mini VTX |
| AVT / TX5823 / TX5828 | Integrated VTX module ICs | Often in “all-in-one” VTX PCBs |
2. Video Input / Processing
| Chip / IC | Function | Notes / Typical Use |
|---|---|---|
| LMH1980 / LMH1981 | Sync separator / video input | For analog video sync processing |
| MAX7456 | OSD (On-Screen Display) | Overlay telemetry / battery info |
| Microcontrollers (STM8 / ATtiny / PIC) | Channel selection, power control, OSD logic | Common in Tramp / SmartAudio VTX |
3. Voltage Regulation & Power
| Chip / IC | Function | Notes / Typical Use |
|---|---|---|
| LM2596 / LM1117 | Linear / Switching Regulator | Provides stable voltage for VTX |
| AMS1117 | Linear Regulator | Low-cost 5V or 3.3V rail for low-power VTX |
| Inductors / Capacitors | Filtering & smoothing | Reduce RF noise on power lines |
4. RF Output / Matching Components
- Discrete components: Inductors, capacitors, microstrip traces for impedance matching (50 Ω).
- Sometimes MMCX / U.FL / SMA connector ICs for external antennas.
💡 Notes
- Many modern VTX modules combine RF PA + PLL + video input + microcontroller in a single small IC or module, like those found on Mobula8.
- High-end HD digital VTX (DJI, Walksnail) use custom ASICs rather than discrete PA chips.
- For typical analog 5.8 GHz micro drones: MAX1476/MAX2606 + LMH1980 + STM8 is a very common combo.
FAQ
Running a 1 W Analog VTX for Extended Periods
- Heat
- 1 W VTX produces significant heat.
- On tiny drones like the Mobula8, heat can damage the VTX, FC, or battery if there’s poor airflow.
Risk increases in warm indoor environments.
Battery Drain
- 1 W output draws more current, reducing flight time significantly.
Tiny cinewhoops may overheat their small LiPo packs if flown at full power for long periods.
Legal Limits
- Many regions restrict 5.8 GHz analog power (often max 25–600 mW).
Flying 1 W indoors or near populated areas could violate regulations.
Interference
- High-power VTX can interfere with nearby electronics and even your own control link.
On tiny drones, the ELRS RX is very close to the VTX, so interference risk is higher.
Practical Recommendation
- For indoor flying: 25–100 mW is sufficient.
- For small outdoor fields: 200–400 mW is usually enough.
- Only use 1 W for long-range outdoor FPV with proper cooling and larger drones.
✅ Summary
- Running 1 W for hours is possible, but not recommended on micro drones due to heat, battery drain, and interference risks.
- Stick to lower VTX power for safe and reliable indoor/outdoor use.
what is the VTX in FPV?
- VTX = video transmitter, the device that transmits the video signal from the drone to the goggles or monitor.
- AIO = all in one, a flight controller that integrates multiple components into a single unit, including the flight controller, ESC (electronic speed controller), and sometimes the VTX.
- smart audio = a feature that allows you to control the VTX settings (such as frequency and power) from the flight controller or goggles, without needing to access the VTX directly.
IRC Tramp = a type of smart audio protocol used by some VTXs, allowing for remote control of the VTX settings.
TBS UNIFY PRO 32 HV V2 = a high-voltage version of the TBS UNIFY PRO 32 VTX, which supports higher power output and is designed for use with high-voltage battery systems.
VTX -- The TBS Unify Pro32 Nano 5.8GHz
The TBS Unify Pro32 Nano 5.8GHz VTX is a compact and feature-rich video transmitter designed for FPV (First-Person View) drone enthusiasts, particularly those involved in racing and freestyle flying. Manufactured by Team BlackSheep, this VTX offers a blend of performance, size, and advanced functionalities.
🔧 Key Specifications
- Operating Voltage: 3–13V (recommended 5V input)
- Dimensions: 15 x 13 x 2 mm
- Weight: 1g
- Antenna Connector: u.FL socket
- Video Format: NTSC/PAL
- Video Input Impedance: 75 Ohm
Output Power: 14dBm (25mW), 20dBm (100mW), 26dBm (400mW), 28dBm (500+mW)
BlackSheep TBS UNIFY PRO32 NANO 5G8 32-bit Video Transmitter
- With the TBS UNIFY PRO32 Nano, we have increased the output power, improved robustness, lowered
- power consumption, added powerful features, and perfected its installation in multi-rotors. In
- short, it is the highest quality, best overall performing nano VTx ever.
- Main features:
- Smallest and lightest video transmitter on the market
- Output power up to 400mW
- Ultra-clear transmission (up to 16 pilots at once!)
- PitMode - power up your quad during a race. Now with team race capability!
- Easy OSD, FC, and RC channel changes, with fallback button menu
- Robust RF amplifier allows powering up without an antenna for hours!
- Clean power-up and video switching
- CE certified
- Specifications:
- Operating voltage: 4.5 - 5.5V
- Operating temperature: ensure normal airflow
- Video input impedance: 75 Ohm
- Weight: 1 gram
- Antenna connector: u.FL socket
- Video format: NTSC/PAL
- Output power:
- 14dBm (25mW),
- 20dBm (100mW),
- 26dBm (400mW)