Leif Compares the Airspy HF+ with the Airspy+Spyverter Combo

Over on YouTube Leif (sm5bsz) has uploaded a video where he compares the Airspy HF+ with the Airspy+Spyverter combination. In the test he compares the two radios at 7 MHz. The signals come in from an antenna, are amplified and then passed into a notch filter which notches at 7.198 MHz. The antenna signal is then passed into an attenuator, and then through a directional coupler and then split into the two radios. A signal generator is used to inject a signal via the directional coupler at the notch frequency, and this signal is used to compare the two radios. This method stops antenna noise from appearing at the notch frequency and so any non-linearities appearing in the notch must be a problem with the radio.

The results that Leif finds are quoted below. They show that although the Airspy HF+ has good linearity, it can still be significantly improved in tough environments by adding a front end filter for the band of interest.

The Airspy HF+ and the Airspy+Spyverter are compared on 7 MHz with and without a band pass filter on the input. Without the filter the HF+ is a little better than the Airspy+Spyverter combo, but when the filter is inserted, the HF+ is MUCH better than the combo.

In an earlier video Leif also compares the two Airspy units on FM broadcast and the 2 meter band. Again he shows that the Airspy HF+ is better than the standard Airspy, but adding a filter to block out the broadcast FM can still help fairly significantly when trying to listen to the 2M band on the HF+.


  1. Pyotr

    We was mis-sold this Airspy HF+. Feel ripped off. It has low noise floor but thats all it has going. WTF is going on with aircraft band?? Signals from bands not even listed go all over what I trying to hear. 🙁

  2. GW

    I wish some of the reviewers had really looked at the HF+ at VHF outside of the BCFM band before I bought my HF+. I have terrible UHF images all over VHF with Tetra signals in the Air band, what appears to be DVB-T signals swamping the 2m band. I contacted Airspy and was told that I needed to add a filter to get rid of UHF signals which flummoxed me as the UHF signal are not particularly strong and I was using a dedicated VHF dipole. I can’t believe overload is the cause of the problem. I read a post on the Radio Reference Forum that suggested that the spurious responses were only suppressed by 25 dB. To be fair, it does work great in the BCFM band although there is a big spur at 98.304 MHz, which a few other people have commented upon. I really bought this unit for VHF as I’m not so interested in the short wave bands, so I have to admit to being a bit disappointed. The best thing about it is the case, which is beautifully made.

    • Evelyn

      I don’t have my unit yet, but I plan on upgrading the firmware once it arrives, an extra 6dB with a firmware upgrade. It will not fix your VHF problem, but at least you will have worked out how to upgrade the firmware, once a new firmware with a fix is released. I know that the TETRA image in the Air Band has been mentioned and a new firmware is being worked on “if the gain of the antenna in higher bands is better than the tuned band, the current firmware thinks it’s OK to increase the gain – expect an update” (was said ~9 days ago).

      “Summary: This release improves the AGC behavior on HF by 6 dB. The impact is better strong signal handling, while still maintaining a nominal sensitivity in other scenarios. Warning: Do not attempt to install this firmware unless you are willing to spend a lot of time debugging your PC, OS and the flashing tools. If not sure, contact a moderator.”

  3. Drone

    @Ken C, You said: “…the only peeve with airspyhf is the antenna sma jack is soldiered directly to the board, they should have used a short jumper wire like the SDRPlay has done, then when somebody has to tighten the nut on the antenna jack it does not break the soldier on the board…”

    Just use a short SMA coax jumper to the radio connector to relieve strain. Never connect/re-connect directly to the radio’s built-in connector. This is OK for a radio like this which targets HF/VHF only. Just make sure you buy/build a quality jumper (beware of the Chinese stuff out there).

  4. Ken C

    what i have set up is, an almost new Dell with AMD Ryzen 7, win 10 did a clean install from an ISO from microsoft because the OEM install was cluttered with third party software, and dual booting with Linux, i notice Linux with GQRX built from a the lastest github sources runs airspyhf better and cleaner than windows 10 with hdsdr, sdr# does better than hdsdr with an extio.dll, and sdrconsole_v3 does better than hdsdr too, but by far my favorite is GQRX on Linux, the only peeve with airspyhf is the antenna sma jack is soldiered directly to the board, they should have used a short jumper wire like the SDRPlay has done, then when somebody has to tighten the nut on the antenna jack it does not break the soldier on the board (i had top open my airspyhf and resolder it to the board after tightening it) other than that the airspyhf is a nice little sdr, i love the heavy steel case it comes in

    so anyone reading this take extra care when tightening the nuts on the antenna jack otherwise you will break the solder connection and have to open it and resolder it,

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