For decades, the Byonics TinyTrack has been the go-to hardware for simple APRS tracking. Connect a serial GPS to one end, wire the audio and PTT lines to a radio on the other end, and you have a self-contained transmit-only APRS beacon. The device runs on a PIC microcontroller and has no screen, no keyboard, and no moving parts. It is purpose-built for one job.

The TinyTrack works well on 1200-baud VHF packet and 300-baud HF packet. The problem is that 300-baud AX.25 packet on HF is a poor performer. It carries no forward error correction (FEC). When a packet is damaged by noise, selective fading, or interference, the receiving station has no way to repair it and no way to request a retransmission. APRS makes this worse because it uses only UI (Unconnected Information) frames, which are one-way broadcasts with no two-way handshaking at all. If the receiving station misses a beacon, it simply waits until the tracker decides to transmit again, typically several minutes later.

VARA changes the picture entirely. Developed by EA5HVK in Spain, VARA wraps every transmission in multiple layers of forward error correction and applies sophisticated DSP to received audio. The result is a modem that can produce reliable copy on signals too weak to hear in the radio speaker, with weak-signal capability comparable to FT-8. The gap in performance between VARA and classic 300-baud AX.25 on HF is not marginal. It is orders of magnitude.

The catch is that VARA is a Windows soundcard application. There is no dedicated hardware device equivalent to the TinyTrack that runs VARA natively. Until recently, running VARA in a mobile tracker context meant carrying a Windows laptop or tablet, which is bulky, power-hungry, and fragile compared to a purpose-built tracker.

Why Not a Raspberry Pi

The obvious question is whether a Raspberry Pi can fill the gap. Some operators have tried. The answer is technically yes, but practically problematic.

Raspberry Pi computers run Linux on ARM processors. VARA is a Windows application compiled for x86/x64 Intel or AMD processors. Making VARA run on a Pi requires WINE to simulate a Windows environment and an x86 CPU emulator to fake the processor architecture. That is two layers of abstraction on top of a relatively underpowered single-board computer. VARA is not a simple utility. It performs real-time, timing-sensitive DSP on audio streams. Emulation overhead directly affects that timing. The result is an unreliable setup that demands significantly more effort to configure and maintain than the outcome justifies.

The Stick PC Solution

WA8LMF (the author of the VARAtrack project) took a different approach. Instead of trying to force VARA onto non-native hardware, he used a Windows stick PC: a small form-factor computer that runs standard 64-bit Windows on a genuine Intel processor, natively, without emulation.

The specific device is the Higole Mini-PC, built around an Intel Celeron J4115 quad-core processor running at 1.5 GHz. It includes a built-in audio system with a 3.5 mm 4-contact TRRS jack, Wi-Fi, Bluetooth 5.2, Gigabit Ethernet, HDMI, two USB 3 ports, and two USB-C ports including one full-function port that carries video, audio, data, and DC power simultaneously. The base model ships with 4 GB of RAM and 64 GB of eMMC storage. A higher-spec version provides 8 GB RAM and 128 GB storage, though the base model is sufficient for the VARAtrack application.

These devices are commercially produced for digital signage, menu boards in fast-food restaurants, airport flight display screens, and conference center signs. They are not hobbyist hardware. Starting price is around USD $130.

The manufacturer’s page is at https://goleminipc.com/products/higolepc-mini-pc-stick-intel-celeron-j4125-windows-11-usb-pd3-0-hdmi-4k-gigabit-ethernet-wifi-5-0-bt-5-2-for-office-home and it is also available on Newegg at https://www.newegg.com/higolepc-4gb-64gb/p/2SW-009E-00001. Note that Amazon listings for similar-looking devices are an older version missing the second full-function USB-C port.

Operating System

The stick ships with Windows 11. WA8LMF reformatted the drive and installed a clean, stripped-down Windows 10 from scratch. All Microsoft Store apps, Cortana, OneDrive, and the AI and Copilot components were removed. This is not just a preference. Windows 11 bloat is a real constraint on a device with 4 GB of RAM and a modest embedded processor. Removing the overhead makes the base model genuinely usable for this application.

There is a secondary reason to use Windows 10. Microsoft has ended support for it, which means no unsolicited forced feature updates. This matters because Windows 11 updates have a documented history of disrupting audio device settings, which would break VARA’s connection to the radio. Since the VARAtrack is not used for general internet browsing or email, the security risk of running an end-of-life OS is considered acceptable.

Software Stack

The installed software stack is: VARA HF modem, VSPE (Virtual Serial Ports Emulator), UIview32 v2.03, Visual GPS, and Precision Mapping 9.0. Everything fits comfortably within the 64 GB eMMC, leaving over 30 GB free even after adding additional ham radio programs.

VSPE performs two functions. First, it bridges VARA’s KISS-over-IP interface to the KISS-over-serial-port format that UIview32 requires, since UIview cannot connect to a KISS modem over IP directly. Second, it splits the GPS data stream received over USB so that both UIview and Visual GPS can read it simultaneously from a single GPS receiver.

Windows Scheduler is configured to launch all required applications automatically in a controlled sequence at power-up. When the stick boots, VARA, UIview32, Visual GPS, and VSPE all start without user intervention.

Radio Interface

VARA is configured to use the stick’s built-in audio system for both transmit and receive. Audio enters and exits through the single 3.5 mm TRRS jack. WA8LMF built a cable that adapts this TRRS plug to the 6-pin mini-DIN data port found on many HF and VHF radios.

Because there is no dedicated PTT line from the stick, the radio must use VOX to key the transmitter. Several Yaesu HF radios including the FT-857 and FT-891 have a dedicated data VOX function in their menus. This function responds only to audio arriving at the rear-panel data port, not the microphone input, and it switches between receive and transmit considerably faster than the standard voice VOX function.

For operators who need hard PTT keying, two options exist. A SignaLink interface has its own built-in VOX and connects via USB. A DigiRig provides virtual COM port PTT control and consolidates both TX/RX audio and PTT keying through a single USB connection to the computer, with a cable running from the DigiRig’s 3.5 mm radio port to the radio’s 6-pin mini-DIN data port.

One USB-A port is used for a USB-connected GPS receiver. The second USB-A port would normally be used for a keyboard/mouse dongle. When a SignaLink or DigiRig is added, one of these ports is consumed by the interface, so a Bluetooth keyboard and mouse are needed instead. The stick’s Bluetooth 5.0 handles this without issue.

Power and Display

Total power draw for the stick and an attached monitor is approximately 6 watts, or 0.5 A at 12 VDC. For mobile and battery-powered field operation, this is a practical figure.

The stick’s full-function USB-C port can carry 1920×1080 HD video, audio, data, and DC power simultaneously over a single USB-C cable. This means a single 12 VDC source can power both the stick and a USB-C-compatible portable monitor through one cable connection.

WA8LMF used a KYY portable monitor, which is a 15.6-inch display panel approximately 6 mm thick in a folding slip case that doubles as a stand. It accepts video via mini-HDMI and power via USB-C, or both through a single full-function USB-C connection. The price is around USD $70.

Alternatively, the stick’s HDMI port and a separate power source can drive any standard HDMI monitor or TV using conventional cabling.

Operating Modes

The VARAtrack setup supports four distinct configurations depending on what hardware is connected at any given time.

Headless, transmit-only mobile tracker: no monitor, no keyboard. The stick boots, launches all apps via Scheduler, acquires GPS, and beacons over VARA. This is the closest equivalent to the original TinyTrack concept.

Mobile with receive display: the portable monitor is attached over USB-C. UIview’s map shows received APRS traffic in addition to transmitting beacons.

Full home station with igate capability: monitor, keyboard, and mouse attached. The stick connects to the internet over Wi-Fi or Ethernet and UIview operates as a full igate, uploading received packets to APRS-IS.

Headless with Bluetooth smartphone link: the VARA IP data stream is bridged over Bluetooth to an APRS application running on a smartphone, providing a display without a dedicated monitor.

Additional Software

Beyond the core tracker stack, WA8LMF also installed VARA FM, Vara Chat, VarAC Chat, the complete FLdigi suite, WSJT-X for FT-8 operation, mmSSTV, EasyPal for digital SSTV, a soundcard oscilloscope and audio generator, an audio recorder and player, a network monitor, and an internet time synchronisation tool. The stick functions as a complete portable ham workstation when a keyboard, mouse, and monitor are connected.

Dayton Hamvention 2026

A presentation on VARA and the VARAtrack was produced for the 2026 Dayton Hamvention. It was released as a YouTube video on KM4ACK’s channel

Further Reading

Full documentation, cloning instructions, and direct comparisons of VARA against 300-baud AX.25 packet across multiple controlled HF experiments are published on WA8LMF’s site at http://wa8lmf.net/VARA/

VARA modem download: https://rosmodem.wordpress.com/ VarAC chat download: https://www.varac-hamradio.com/

http://wa8lmf.net/VARA/VARAtrack/index.htm

The post VARAtrack: A Compact APRS-over-VARA Tracker Built on a Windows Stick PC appeared on Hamradio.my - Amateur Radio, Tech Insights and Product Reviews by 9M2PJU.