Airspy HF+ Discovery
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| Frequency | HF: 0.5 kHz - 31 MHz, VHF: 60 - 260 MHz |
| Bands | VLF, LF, MF, HF, VHF (60-260 MHz) |
| Power | RECEIVE ONLY — no transmit capability. |
| Modes | All modes via SDR software (AM, FM, SSB, CW, digital, etc.) |
| Weight | 30 g (1.1 oz) - ~30g estimated. Ultra-compact USB dongle form factor. |
| Connector | SMA-F |
| Year | 2019 |
| antenna | SMA-F |
| usb | USB (power + data — bus powered) |
| power req | USB bus powered. No external power required. Works with Raspberry Pi. |
Strong HF performance at a modest price. 110 dB of dynamic range rivals receivers costing far more, with -140 dBm sensitivity. The DSP handles gain automatically (no attenuators or preamps needed), and a polyphase HR mixer rejects up to the 21st harmonic. SpyServer enables remote/multi-user use. It won a WRTH 2020 award, works with all major software, is USB powered, and is ultra-compact.
Receive only (no transmit). HF stops at 31 MHz (no 6 m). There is a gap between 31-60 MHz. 660 kHz max bandwidth (an RTL-SDR does 3.2 MHz). No waterfall storage. Several times the price of an RTL-SDR V4 (but far better HF performance). A 1-year warranty, with a flat-fee out-of-warranty repair.
A high-performance HF/VHF SDR receiver. The HF+ Discovery delivers 110 dB of dynamic range and -140 dBm sensitivity in a modestly priced USB dongle, performance that matches dedicated HF receivers costing far more. If you listen on HF (shortwave, amateur bands, aviation) and want the cleanest spectrum possible without attenuators or manual gain management, it is a strong choice.
The Airspy HF+ Discovery is a premium receive-only SDR aimed squarely at serious HF listeners, and it punches far above its modest size and price. It covers the shortwave spectrum from 0.5 kHz up to 31 MHz, plus a VHF segment from 60 to 260 MHz, and connects to a computer over USB. What it does not do is transmit — it is purely a receiver.
Its reputation rests on dynamic range. Rather than the brute-force direct sampling used by some rivals, it uses a polyphase harmonic-rejection mixer feeding a sigma-delta ADC, an architecture that keeps strong nearby signals from desensitizing the receiver. The result, confirmed in independent lab comparisons, is performance that trails only the much pricier benchmark receivers while costing a fraction as much — it won World Radio TV Handbook's best-SDR award in 2020. The main compromises are a plastic case and a relatively narrow instantaneous bandwidth.
It remains a current product and is widely regarded as the best HF value in SDR. Above it sit the reference-grade Microtelecom Perseus and WinRadio Excalibur; below it, the budget RTL dongles cannot approach its HF dynamic range.