HFU HF Underground

Technical Topics => SDR - Software Defined Radio => Topic started by: ChrisSmolinski on November 27, 2017, 2353 UTC

Title: AirSpyHF+
Post by: ChrisSmolinski on November 27, 2017, 2353 UTC
Look what finally arrived in the mail today. Photographed next to the SDR-14, for size comparison.

From the first few minutes of use, seems pretty good. I will write up a full review and some side by side comparisons against my other SDRs. And then I will write some software for it  :)

(https://i.imgur.com/hBNnvVA.jpg)
Title: Re: AirSpyHF+
Post by: Ray Lalleu on November 30, 2017, 2044 UTC
An early review of the Airspy HF+ is available in the December issue of "Radio User" (UK).
Mike Richards got a preproduction unit and goes through the new design:
-coverage: LF to VHF (up to 260 MHz)
-using a new type of mixer (frequency changer) ahead of the ADC: 16 phase mixer, giving adequate rejection of harmonics up to the 21th harmonic, so there's no need to use a bank of many RF filters ahead of the mixer, also no need of high gain preamplifier
-using a low phase-noise oscillator
-using a Sigma-Delta 16 bit ADC, followed by a digital filter (design said to produce less quantization noise)
- from there, a decimation stage (as usual), then the output
From only a few days of use, Mike Richards noticed a "pretty amazing" strong signal performance on VHF (around 138 Mhz) and on HF (around 7 MHz).

The key components makers were not named. Maybe we are at the beginning of a new generation of (almost) low cost and high performance SDRs ?

Title: Re: AirSpyHF+
Post by: curious george on December 02, 2017, 0400 UTC
Here's a free download link for the entire issue for those interested:

https://vk.com/doc448173336_454112114?hash=909522e91419174a37&dl=GQ4TONRUGAZTG:1511623889:839c02fd4badd7debe&api=1&no_preview=1 (https://vk.com/doc448173336_454112114?hash=909522e91419174a37&dl=GQ4TONRUGAZTG:1511623889:839c02fd4badd7debe&api=1&no_preview=1)

Download link was found here, in case it no longer works:

https://emagazinepdf.com/2017/11/radio-user-december-2017/ (https://emagazinepdf.com/2017/11/radio-user-december-2017/)
Title: Re: AirSpyHF+
Post by: ChrisSmolinski on December 02, 2017, 1541 UTC
I've been generally impressed so far. I have run into some images down on the LW band from SWBC stations, Youssef said they are still tweaking things (this can be done in software, via new DLLs). I have not run across any images on MW or HF.
Title: Re: AirSpyHF+
Post by: Oliver on December 07, 2017, 1108 UTC
Here a nice comparison by Nils Schiffhauer (DK8OK), between the Elad FDM-S2 & the new AirSpyHF+ with 12 audio samples.
All recording have been made on a 20 meter quadloop antenna.

https://dk8ok.org/2017/12/06/airspy-hf-what-you-hear-is-what-you-get/
Title: Re: AirSpyHF+
Post by: ChrisSmolinski on December 07, 2017, 1804 UTC
My comparison of the AirSpyHF+ vs the netSDR, with several audio recordings: http://www.radiohobbyist.org/blog/?p=2361