Aurora AU-520

500W Dual-SCU HF/6m Software-Defined Transceiver

A complete high-power station in one compact chassis. The FlexRadio Aurora AU-520 integrates an advanced dual-SCU SDR, 500W HF transmitter, high-power automatic antenna tuner and AC power supply, with the flexibility of SmartSDR computer and remote operation.

No Screen. No Compromises in RF Performance.

The AU-520 is supplied without an integrated touchscreen or Maestro-style front panel. It is intended for use with compatible SmartSDR software on a computer, an external Maestro controller or supported remote clients. The same dual-SCU receiver and 500W RF capabilities are available without paying for an integrated display.

A high-performance station, without the stack of equipment

The FlexRadio Aurora AU-520 brings a new level of integration to HF and 50MHz amateur radio. Its innovative polar-modulation transmitter delivers up to 500W PEP on supported HF bands and 200W PEP on 6m, without requiring a separate linear amplifier.

The transceiver also incorporates an automatic antenna tuner and wide-range AC power supply, dramatically reducing the number of separate components and interconnecting cables required for a high-power station.

Unlike conventional compact SDRs with a single receiver architecture, the AU-520 includes two independent Spectral Capture Units. This provides four slice receivers, true diversity and the additional isolation and flexibility required for advanced multi-band operating and contesting.

500W power, with far less wasted energy

Aurora's polar-modulation architecture separates amplitude and phase information, allowing specialised high-efficiency switching amplification instead of relying on a conventional linear power amplifier.

FlexRadio quotes approximately 80% nominal transmitter efficiency. The result is significantly less wasted heat and electrical power for a given RF output compared with many traditional high-power systems.

Efficiency and AC consumption vary with output power, mode and operating conditions.

Two independent RF paths. Four receivers.

The AU-520 uses two independent Spectral Capture Units to digitise signals from separate antenna sources. Each SCU supports flexible receive processing, with four slice receivers available across the system.

This architecture enables operators to monitor multiple frequencies across bands, receive through different antennas and configure advanced workflows without multiple separate transceivers.

Engineered for strong-signal environments

The AU-520 combines high-resolution 16-bit direct sampling with sophisticated digital processing and seventh-order amateur-band preselectors. The architecture delivers strong interference rejection for crowded bands, DX operation and complex contesting environments.

Your station, on the screen you choose

The screenless AU-520 is designed around FlexRadio's SmartSDR ecosystem. Use compatible computer software or a separate Maestro controller to view panadapters, waterfalls, receiver controls and transmit settings.

SmartLink enables supported remote operation over an internet connection, while MultiFlex offers two-client operation. DAX provides digital audio and IQ channels for compatible software and data-mode applications.

Designed around complex station needs

Two high-power transmitting antenna connections, two receive-only inputs and two transverter ports provide the flexibility required by serious amateur-radio stations. Dual SCUs allow different receiver antennas to be used simultaneously.

GNSS-referenced frequency stability

The AU-520 includes an integrated GNSS receiver supporting GPS, Galileo, GLONASS, QZSS and SBAS. With suitable satellite reception, the radio achieves highly accurate frequency control without regular manual oscillator adjustment.

FlexRadio quotes approximately 0.001ppm GNSS-referenced stability and 0.5ppm TCXO stability. An optional high-performance GPSDO adds a precision 10MHz output for suitable external station equipment.

AU-520 vs AU-510: Which is right for you?

Both the AU-510 and AU-520 are screenless Aurora radios offering the same 500W HF/200W 6m transmitter, built-in automatic tuner, AC power supply and SmartSDR operating environment. The AU-520 adds a second SCU and more advanced receiver resources.

Built-in AC power and modern digital capability

The integrated supply accepts 80–264V AC, eliminating the need for an external high-current DC power supply. The AU-520 is designed for SmartSDR integration with suitable computers and compatible digital-mode applications.

It supports SSB, CW, AM, SAM, FM, RTTY and compatible software-based digital modes. SmartSignal adaptive predistortion and Controlled Envelope SSB are included in the Aurora platform's advertised feature set, subject to supported firmware availability.

One integrated platform for the station you want

Important information before ordering

No built-in screen: A compatible SmartSDR control device or external Maestro controller is required.

Output power: Up to 500W PEP HF and 200W PEP 6m. Use appropriately rated antennas, coaxial cables, switches and accessories.

Power supply: Integrated 80–264V AC input. Direct 13.8V DC operation is not supported.

Automatic tuner: Matching is provided for suitable antennas within the stated 3:1 SWR range.

GPSDO: High-performance 10MHz output reference is optional; standard GNSS support is included.

Software: Some advertised capabilities are subject to installed SmartSDR firmware, applicable licences or subsequent updates.

Aurora User Guide

For operating instructions, SmartSDR configuration and technical guidance, consult the official Aurora user guide.