For as long as most of us have been in the hobby, a "serious" HF station has meant a stack of boxes: a transceiver, a separate linear amplifier, an antenna tuner, and a hefty power supply to feed it all — each with its own cabling, its own cooling, and its own footprint on the desk. FlexRadio's new Aurora Series sets out to change that completely. It's being billed as the world's first truly integrated 500-watt SDR transceiver, folding the amplifier, tuner and power supply into the same compact chassis as the radio itself.
Announced at the 2025 Dayton Hamvention and now shipping, Aurora isn't a replacement for the existing FLEX-6000 and FLEX-8000 ranges — it sits alongside them as a higher-power, all-in-one option, while remaining fully compatible with the SmartSDR software and remote operation tools that existing Flex owners already know.
What makes Aurora different?
The headline feature is the transmitter itself. Rather than using a conventional RF exciter feeding a separate linear amplifier, Aurora uses a transmitter design based on Polar Modulation, generating SSB, CW, AM, FM, RTTY and digital modes directly at power. The result is a genuinely integrated 500W PEP amplifier stage that FlexRadio quotes at around 80% nominal efficiency, with peaks of up to 90%.
That efficiency figure matters more than it might first appear. A traditional 100W transmitter running at 40% efficiency has to dissipate around 150W as heat. Run that same 100W at 80% efficiency, and the heat to get rid of drops to roughly 25W. Scale that up to 500W output, and the difference in cooling, fan noise, power draw and overall size becomes huge — which is exactly how FlexRadio has managed to fit a 500W amplifier, tuner and supply into such a small chassis.
Every Aurora model also includes a built-in automatic antenna tuner (matching up to 3:1 SWR), an integrated AC/DC power supply that will run from 80–264VAC, and an integrated multi-constellation GNSS receiver (GPS, Galileo, GLONASS, QZSS and SBAS) that keeps the radio's frequency reference accurate without any manual adjustment. An optional high-performance GPSDO upgrade is available for those who want an external 10MHz reference output as well.
The Aurora line-up: four variants
The Aurora Series launches with four models, built around two underlying platforms — a single-SCU radio (AU-510) and a dual-SCU radio (AU-520) — each available with or without an integrated display:
- AU-510 – the entry point to the range. A single-SCU (Spectral Capture Unit) radio offering two independent receivers and two simultaneous panadapters. Roughly comparable to a FLEX-8400 with the new 500W Aurora transmitter built in.
- AU-510M – the AU-510 with an integrated 8-inch, 1920×1200 IPS touchscreen display (Maestro front panel) built into the chassis, plus an external monitor output.
- AU-520 – the flagship dual-SCU model, with four independent receivers, four panadapters, true diversity reception, and contest-grade 7th-order bandpass filters. Roughly comparable to a FLEX-8600 with the Aurora transmitter built in.
- AU-520M – the AU-520 with the same integrated 8-inch 1920×1200 IPS display and external monitor port as the AU-510M.
The non-"M" models (AU-510 and AU-520) are "headless" by design — there's no built-in screen or front panel. They're intended to be run via SmartSDR on a PC, Mac, iPad or iPhone, or via a separate Maestro console, which makes them a neat fit for rack-mounted shacks, remote sites, or anyone who prefers to operate from a big monitor rather than a small built-in display.
Key specifications at a glance
| Spec | AU-510 | AU-510M | AU-520 | AU-520M |
|---|---|---|---|---|
| HF output power (160m–10m) | 1–500W PEP (125W AM) | |||
| 6m output power | 1–200W PEP (50W AM) | |||
| Nominal efficiency | ~80% (peak up to ~90%) | |||
| Spectral Capture Units (SCUs) | 1 | 1 | 2 | 2 |
| Independent receivers / slices | 2 | 2 | 4 | 4 |
| Simultaneous panadapters | 2 | 2 | 4 | 4 |
| ADC sample rate | 16-bit @ 122.88 Msps | 16-bit @ 245.76 Msps | ||
| Receive frequency coverage | 30 kHz – 54 MHz | |||
| Built-in display | None (headless) | 8" 1920×1200 IPS touchscreen | None (headless) | 8" 1920×1200 IPS touchscreen |
| Diversity reception / SO2R features | — | — | True diversity RX, OTRSP, 7th-order contest filters | |
| Built-in antenna tuner | Yes, up to 3:1 SWR | |||
| Integrated GNSS reference | Yes (optional GPSDO upgrade available) | |||
| Control / software | SmartSDR (PC, Mac, iPad, iPhone) and/or Maestro | |||
Standard across the whole range
Whichever Aurora model you go for, a few key technologies come as standard:
- SmartSignal™ adaptive predistortion – actively cleans up the transmitted signal and reduces intermodulation distortion (IMD).
- Controlled Envelope SSB (CESSB) – up to 3dB more "talk power" on SSB without adding distortion.
- MultiFlex™ – allows two independent SmartSDR clients to use the same radio at the same time, useful for shared shacks or remote/local split operation.
- SmartLink™ remote operation – the same remote-access platform used across the FLEX-8000 range, so Aurora can be set up as a high-power remote HF station.
- Transverter support – XVTR ports for adding VHF/UHF/microwave transverters, just as on existing FLEX-6000/8000 radios.
Which Aurora is right for you?
If you're coming from a traditional setup of a 100W transceiver plus a separate amplifier, any of the Aurora models effectively replace both boxes (and the tuner and PSU) with one. Beyond that, the choice mostly comes down to two questions:
Do you want a built-in screen?
If you'd rather have everything in one box — including the display — the "M" models (AU-510M / AU-520M) add the integrated 8-inch touchscreen and an external monitor output. If you're happy running SmartSDR on a laptop, tablet, or a separate Maestro console (or building a remote/rack station), the standard AU-510 / AU-520 headless versions free up space and let you choose your own display.
Do you need the extra receivers and contest features?
The AU-510 / AU-510M give you two receivers and two panadapters — plenty for general operating, DXing and most digital modes. The AU-520 / AU-520M step up to four receivers, four panadapters, true diversity reception and SO2R-ready contest filtering with OTRSP support for logging software such as N1MM+ — aimed squarely at serious contesters and multi-band monitoring.
Availability
The Aurora Series began shipping in late 2025, with FlexRadio's standard ordering process applying — orders are pre-authorised on placement but only charged when the unit ships. Given the price class of these radios, international buyers should also factor in shipping, import duty and VAT on top of any US list pricing when budgeting for an Aurora model.
View FlexRadio Systems at ML&S
Closing thoughts
The Aurora Series represents one of the biggest architectural shifts FlexRadio has made since the original FLEX-6000 series. By folding a 500W amplifier, tuner and power supply into the radio itself — and doing it efficiently enough that the whole package stays compact and cool — Aurora removes a lot of the cabling, RFI headaches and desk space that come with a traditional multi-box HF station. Whether you go for the simplicity of the AU-510, the all-in-one convenience of an "M" model with its built-in display, or the dual-receiver firepower of the AU-520 for contesting, it's a genuinely new way to put a high-power SDR station together.
Disclaimer: This post is an independent overview based on FlexRadio's published product information for the Aurora Series, current at the time of writing. Specifications, pricing and availability are subject to change by the manufacturer — please contact ML&S or check the FlexRadio website for the latest details before ordering.
