DIY Long-Range Digital FPV & Telemetry Link with ALFA AWUS036ACH and wfb-ng (2026)

Author: Yupitek Technology Team (Official ALFA Network Distributor, Taiwan) Audience: Drone enthusiasts, makers, security researchers, agri-spray and inspection UAV developers Difficulty: ★★★☆☆ (requires basic Linux and flight controller knowledge)

1. Why Build a Digital FPV Link with an ALFA Card?

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If you have used analog FPV (5.8 GHz analog video), you know the drill: signal obstruction turns the screen into snow, range drops fast, and anyone with a receiver can watch your feed — no encryption, no telemetry return channel.

Over the past year, our team has set up links for agri-spray operators, inspection teams, and security training clients. One question kept coming up: Can I use a common ALFA USB adapter with open-source software to build a digital, encrypted, long-range link that carries both video and telemetry?

The answer is yes — and it is simpler than you might think.

Compared to traditional analog FPV, running the open-source wfb-ng on an ALFA adapter gives you several decisive advantages:

• Low latency: Raw WiFi injection bypasses 802.11 ACK and handshake overhead. End-to-end delay drops to tens of milliseconds — FPV feel is close to analog.
• Digital encryption: Video and telemetry packets use libsodium encryption. Even if someone captures the signal, they cannot decode your feed or flight data.
• One link, multiple streams: A single adapter on one frequency handles:
  • Live video (RTP / RTSP)
  • MAVLink telemetry (bidirectional, flight controller ↔ ground station)
  • A TCP/IP tunnel (for VPN, SSH, or file transfer)
• TX diversity: Multiple adapters can work together for transmit diversity, improving obstruction resistance.
• Open source, fully customizable: The ALFA AWUS036ACH combined with wfb-ng costs a fraction of commercial digital FPV systems (DJI O3, Walksnail, etc.) — and every line of code is open.

2. What This Is: wfb-ng Explained

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wfb-ng (Wireless Fibre / WiFi Broadcast – next generation) is an open-source digital FPV and telemetry project with a clever core idea:

It does not use WiFi as a “network.” It uses WiFi as a “radio.”

Standard 802.11 was designed for local area networking — association, ACK, retransmission. Over long distances, with moving vehicles and weak signals, that overhead becomes a liability. wfb-ng takes a different approach with raw WiFi injection:

• The adapter enters monitor mode — it does not “connect” to anything.
• Raw WiFi frames are injected directly. No ACK, no retransmission (FEC forward error correction handles packet loss).
• This bypasses the range and latency limits of standard 802.11, pushing distance and stability to the hardware’s physical limit.

In simple terms: it turns a common USB adapter into a pair of “digital radios” that can carry RTP video, MAVLink telemetry, and even an IP tunnel.

• Project homepage (GitHub): https://github.com/svpcom/wfb-ng.git
• Widely used in the PX4 / ArduPilot ecosystem for DIY digital FPV. Active community, and a common open-source link in the Ukrainian drone community.

3. The Star: ALFA AWUS036ACH

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The “radio” of this link is the ALFA AWUS036ACH.

It uses the Realtek RTL8812AU chipset with 802.11ac (WiFi 5), dual-band 2.4 GHz / 5 GHz, USB 3.0 Type-C, and detachable RP-SMA antennas. Critically, wfb-ng’s official test hardware runs AWUS036ACH on both ends at 5 GHz. This adapter is the model the project author validated for the most stable driver support.

Three reasons it stands out:

1. Enough power: ALFA’s signature high-power design, combined with external high-gain antennas, delivers far better long-range performance than any laptop internal card.
2. Monitor mode + injection: With the patched driver (detailed below), RTL8812AU reliably supports monitor mode and raw packet injection — the prerequisite for wfb-ng.
3. Universal and durable: USB form factor works on both the air and ground ends. No need to buy different adapters for different machines. If one fails, swap in another.

4. Hardware List

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The link splits into Drone (airborne) and Ground Station sides.

Drone (Airborne)

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Ground Station

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Note: For receive-only (RX) setups, any adapter that supports monitor mode will work — even a router flashed with OpenWRT. But the official tested setup and this guide use the AWUS036ACH.

5. Software List

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Operating System

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• Raspberry Pi OS / Debian / Ubuntu (Linux kernel ≥ 4.x)

Core Projects

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• wfb-ng (svpcom/wfb-ng): digital FPV / telemetry main program
• Patched driver:
  • RTL8812AU → svpcom/rtl8812au (branch v5.2.20, install via dkms)
  • RTL8812EU → svpcom/rtl8812eu
  • After loading, the adapter appears as rtl88xxau_wfb (or rtl8812eu)

System Dependencies

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sudo apt update
sudo apt install -y \
  python3-all libpcap-dev libsodium-dev libevent-dev \
  python3-pip python3-pyroute2 python3-twisted python3-serial \
  python3-all-dev python3-venv iw socat debhelper dh-python \
  fakeroot build-essential python3-msgpack python3-setuptools \
  libgstrtspserver-1.0-dev

Encryption

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• libsodium: Use wfb_keygen to generate drone.key (airborne) and gs.key (ground station)

Ground Station Playback

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• QGroundControl: monitor flight controller status and telemetry
• GStreamer / RTSP: receive and play live video from the airborne end

6. GitHub Links and ALFA AWUS036ACH Spec Sheet

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Official Links

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ALFA AWUS036ACH Spec Sheet

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7. Step-by-Step Setup

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This section has four parts. Path A (Raspberry Pi Quick Start) is the most recommended — nearly a burn-and-go experience. Path B is for manual x86 Linux ground station installation. Paths C and D cover key pairing and configuration; both paths use those.

A. Raspberry Pi Quick Start (Recommended)

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wfb-ng provides pre-built Raspberry Pi images. Flash one for the drone and one for the ground station — boot and they work.

1. Download and flash the image

Go to the wfb-ng GitHub Releases page, download the latest *.img.gz, extract it, and flash it to two SD cards (one for the drone, one for the ground station).

# Extract the image (filename varies by release)
gunzip wfb-ng-*.img.gz
# Flash to SD card using Raspberry Pi Imager, dd, or balenaEtcher

2. Insert the adapter, boot, and SSH in

Plug an ALFA AWUS036ACH into both boards, power on, and SSH in (default IP and credentials below):

ssh [email protected]
# Password: raspberry

3. Enable Ground Station services

On the ground station Pi, run:

sudo systemctl enable wifibroadcast@gs
sudo systemctl enable rtsp
sudo systemctl enable fpv-video
sudo systemctl enable osd
sudo reboot

4. Enable Drone services

On the drone Pi, run:

sudo systemctl enable wifibroadcast@drone
sudo systemctl enable fpv-camera
sudo reboot

5. Monitor link status from the ground station

wfb-cli gs

When you see connection, channel, and packet loss information, the link is up. Open QGroundControl to access telemetry and video.

B. Debian / Ubuntu Ground Station Manual Installation

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If you are using an x86-64 Linux desktop or laptop as the ground station, install manually.

1. Install dkms and the patched driver

git clone -b v5.2.20 https://github.com/svpcom/rtl8812au.git
cd rtl8812au
sudo ./dkms-install.sh

2. Verify the adapter is using the wfb-ng driver

# Should show wlan0 with MTU 2312
ifconfig

# Driver name should be rtl88xxau_wfb (RTL8812AU) or rtl8812eu (RTL8812EU)
ethtool -i wlan0

3. Run the official auto-install script

curl -o install_gs.sh https://raw.githubusercontent.com/svpcom/wfb-ng/refs/heads/master/scripts/install_gs.sh
sudo bash ./install_gs.sh

4. Monitor the link

wfb-cli gs

C. Key Pairing

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wfb-ng video and telemetry are encrypted. The airborne and ground station ends must use matching keys to communicate.

# Generate keys (do this on the drone side, then distribute)
wfb_keygen

# Place drone.key on the drone
# Place gs.key on the ground station
# Both must match — otherwise the link shows "connected" but no data

If you used Path B’s auto-install script (install_gs.sh), it generates and configures keys automatically. For manual installation, make sure drone.key and gs.key belong to the same pair.

D. Key Configuration File: /etc/wifibroadcast.cfg

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/etc/wifibroadcast.cfg is wfb-ng’s core configuration file. These are the parameters you will most likely need to adjust:

[common]
# Channel 165 = 5825 MHz (5.8 GHz band)
wifi_channel = 165

# Set the country code to 'BO' (Bolivia) to unlock maximum TX power
wifi_region = 'BO'

[drone]
# link_domain MUST be identical on both drone and ground station
link_domain = "my_wfb_link_01"

[drone_mavlink]
# Receive MAVLink from the flight controller UART (set UART to 1500000 baud)
peer = 'serial:ttyS0:1500000'

[drone_video]
peer = 'listen://0.0.0.0:5602'

[gs]
# Same as above — must match the drone
link_domain = "my_wfb_link_01"

Three most common pitfalls:

1. wifi_channel must match on both ends: This guide uses 165 (5825 MHz, 5.8 GHz). Set it the same on both drone and ground station.
2. link_domain must match on both ends: This is the link identifier. Different values means no connection.
3. Flight controller UART baud rate must be 1500000: peer = 'serial:ttyS0:1500000' requires the flight controller UART to be set to 1500000 baud, or MAVLink will not work.

8. Practical Notes and Common Pitfalls

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This section covers issues we actually hit during real deployments. Read it.

Pitfall 1: Insufficient Adapter Power Causes Port Resets and Packet Drops

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The AWUS036ACH draws significant current during TX bursts. Plugged into a Raspberry Pi standard USB 2.0 port, the Pi’s USB power cannot sustain the peak draw. Result: adapter port resets, link drops, packet corruption, frozen video.

Solution (mandatory on the drone side):

• Power the adapter directly from a 5V BEC (not from the Pi’s USB). Connect the BEC output to the adapter.
• Add a 470µF low-ESR capacitor across +5V and GND at the adapter to absorb TX current spikes.
• On the ground station side, a laptop USB 3.0 port with the original USB 3.0 cable usually provides enough power — no extra BEC needed.

This single step determines whether your link is stable. We have seen countless cases of packet loss traced back to poor power delivery.

Pitfall 2: Encryption Errors / No Connection

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If wfb-cli gs shows “connected” but there is no video or telemetry, the causes are almost always:

• Key mismatch: Verify drone.key on the drone matches gs.key on the ground station.
• Channel or link_domain mismatch: Both ends must have identical wifi_channel and link_domain settings.

Debug command:

# Check ground station service logs for encryption / connection errors
journalctl -xu wifibroadcast@gs

Pitfall 3: Regulatory Compliance (Important)

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This link transmits radio waves. It is a wireless transmission device.

• Verify that your local regulations permit this type of WiFi transmission at the power level and frequencies you plan to use.
• Taiwan, China, the EU, and the US each have their own rules for 5.8 GHz ISM band TX power, available channels, and “non-association” transmission.
• Setting wifi_region = 'BO' unlocks the hardware power ceiling, but it does not make it legal in your country. Adjust channels and power to comply with local radio regulations.
• Use only in authorized environments (private farmland, closed test ranges, training facilities). Do not interfere with other communications.

9. Conclusion

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With a single ALFA AWUS036ACH and the open-source wfb-ng project, we built a link that delivers:

• Cost advantage: Total BOM cost is far below any commercial digital FPV solution.
• Open source: Every line of code, every driver, every configuration is publicly available.
• Fully customizable: Channels, power, encryption keys, MAVLink routing — all under your control.
• Long range: Digital video and telemetry on one link, 5 GHz field-tested range well beyond analog, with encryption and obstruction resistance.

For agri-spray, inspection, security training, or anyone who wants to understand how digital FPV really works under the hood, this is a path worth walking.

Our team will continue sharing ALFA adapter drone-link implementation notes on this blog. If you run into issues during setup, feel free to reach out — hands-on building is the fastest way to learn.

Appendix: Glossary for Beginners

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If this is your first time with drone link technology, here is a quick plain-English reference for the terms used in this guide:

In one sentence: wfb-ng turns the ALFA adapter into a dedicated drone radio station, letting video and flight data travel long distances over an open-source, encrypted link — your own private channel.

References

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• wfb-ng project (svpcom/wfb-ng): https://github.com/svpcom/wfb-ng.git
• ALFA AWUS036ACH product page: https://yupitek.com/en/products/alfa/awus036ach/
• Patched driver (RTL8812AU): https://github.com/svpcom/rtl8812au
• Patched driver (RTL8812EU): https://github.com/svpcom/rtl8812eu
• PX4 WFB-ng tutorial: https://docs.px4.io/main/en/tutorials/video_streaming_wfb_ng.html

This article was written by the Yupitek technical team (official ALFA Network distributor, Taiwan), based on wfb-ng official documentation and hands-on implementation experience. Before building this link, verify your local radio regulations and adjust TX power and frequencies accordingly.