Tag Archives: Software Defined Radio

Airspy HF+ SDR Now Available to Order

As reported recently on the SWLing Post that the Airspy HF+ would be available “really, really, really soon”, the rumor has become reality–this new SDR receiver is for sale on Airspy’s main sale site www.Itead.cc.

The direct link for purchase is: https://www.itead.cc/airspy-hf-plus.html. The price in US dollars is a very reasonable $199.00, considering the high performance evident by the few test units “in the wild” recently.

There was an initial $50-off coupon code available first come, first served this morning for the first 100 orders. These were snapped up quickly; I was fortunate to make it into that limited group and I saved $50 each off a couple of HF+ units. My intent is to pair them up for full coverage of the medium wave band–while recording I/Q WAV files)–using two receiver “instances” within Studio 1 or SDR-Console software. (The alias-free bandwidth of the HF+ is a modest 660 kHz, a trade-off this receiver makes to deliver high performance at a low price.) I expect a EXTIO DLL file to be available soon for use in EXTIO software like Studio 1 (or the EXTIO version of SDRuno which I also use).

I plan to be comparing the HF+ to my current Elad FDM-S2 SDR; based on specs and early user reports, it should be a tight race.

UPDATE: I’ve learned that the shipping timeframe for the HF+ is the beginning of December (approx. three weeks). There is also a U.S. distributor who is kindly offering a similar $50-off deal: https://v3.airspy.us/product/airspy-hfplus/

Simon Brown, author of the popular SDR-Console software versions, closely compares the Airspy HF+ ($199 USD) against a RFspace NetSDR ($1449 USD w/o options): http://www.sdr-radio.com/Radios/Airspy/AirspyHF

Who else is planning on an Airspy HF+ purchase? What are your monitoring interests you plan to use it for? Please comment below and share your thoughts with other SWLing Post readers!

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington. He’s a regular contributor to the SWLing Post.

Airspy’s latest: The Airspy HF+ SDR

6 Replies

SDR manufacturer, Airspy, has a new product shipping “really really really soon” (per their website). The Airspy HF+ promises improved frequency agility through the use of high-performance passive mixers with a polyphase harmonic rejection structure. Airspy states that no external band filters are required as they are with many budget SDRs.

There are many other improvements over their previous iterations. Here’s the product information copied from the Airspy HF+ page on Airspy’s website:

(Source: Airspy)

The Software Defined Radio revolution brought great flexibility in VHF and UHF reception. Today we offer the best wide band receivers which address these needs. We also provide a high performance extension for weak-signal wide band reception on HF – something other competing solutions fail to address efficiently.

Airspy HF+ is a paradigm shift in high performance HF radio design. It is a joint effort between Airspy, Itead Studio and a top-tier semiconductor company to build a state of the art SDR for HF and VHF bands.

Like most high-end HF receivers, the HF+ uses very high dynamic range ADC’s and front-ends. But unlike the current offerings in the market, it also brings more frequency agility by using high performance passive mixers with an excellent polyphase harmonic rejection structure. No external band aid filters are required like the lower end HF receivers, which makes it the ideal companion for light portable high performance operation.

Both the architecture and level of integration achieved in this design allow us to bring top performance reception at a very affordable price.

All the major SDR software is supported. Check the download page.

State of the Art SDR streaming technology!

We concentrated state of the art DSP and networking techniques into our SpyServer software to allow multiple users to stream high quality IQ data from the same receiver at the same time. No compromises in the quality were made like it is usually done in Web SDR interfaces. You get actual IQ data you can process with your plugins and extract the last bit of information out of it.
The server software is highly scalable and can run on computers as small as the $7 Orange Pi Zero to top end 64bit servers with multiple cores/cpus, including the popular Raspberry Pi series.

HF Tuner

Airspy HF+ achieves excellent HF performance by means of a low-loss band filter, high linearity LNA, high linearity tunable RF filter, a polyphase harmonic rejection (HR) mixer that rejects up to the 21st harmonic and multi-stage analog and digital IF filtering.
The 6 dB-stepped AGC gain is fully controlled by the software running in the DSP which optimizes the gain distribution in real time for optimal sensitivity and linearity. Harmonic rejection is a key issue in wide band HF receivers because of the large input signal bandwidth of the input signal. The output of the IF-filter is then digitalized by a high dynamic range sigma delta IF ADC for further signal processing in the digital domain.

VHF Tuners

Excellent VHF performance is also achieved by using optimized signal paths composed of band filters, high linearity LNAs with a stepped AGC, a polyphase harmonic rejection mixer and IF filters optimized for their respective bands.
The amplifier gain is switchable in 3 dB-steps and fully controlled by the AGC running in the DSP. The RF signal is converted to baseband by a high linearity passive mixer with a polyphase harmonic rejection structure. The low-IF signal is then converted into the digital domain by the same IF ADC used in the HF chain.

IF Sampling

The IF analog to digital converter (ADC) is a 4th order multi-bit noise shaping topology; it features very high dynamic range and linearity. The IF-ADC sampling rate is determined by a control algorithm running in the embedded DSP. This advanced technique adjusts the sampling rate depending on the tuning frequency with the goal of avoiding the disturbances and spurs generated by the switching discrete-time sections of the IF-ADC.

Digital Down Converter

Once the IF signal is digitalized, the high sample rate I/Q stream is then frequency translated and processed with cascaded CIC and FIR decimation stages. After every stage, the sample rate is reduced and the resolution increased. The final signal at the output has 18bit resolution and an alias rejection performance of 108 dBc. The data is then scaled to 16bit and sent to the Micro-Controller for streaming over USB.

Architectural Advantages

The main advantages over techniques from the legacy super-heterodynes up to the now mainstream direct sampling is that the whole receiver chain is well protected against out of band blockers while still relaxing the RF filtering constraints, making it simple and cost effective.
The natural filtering of the sigma-delta ADC combined with the excellent linearity and sensitivity of the analog chain reaches an unprecedented level of performance and integration.

Use it over the network!

Connect as many SDR applications as needed to the HF+, over the Internet or in your own local network with near zero latency thanks to the new SPY Server software.
This setup basically brings all the flexibility of Web based SDRs while still benefiting from the full power of desktop applications. The IQ data is processed in the server with state of the art DSP and only the required chunk of spectrum is sent over the network. What is sent is the actual IQ signal, not compressed audio. This means you can use all your favorite plugins to process the IF, eliminate noise and perform heavy lifting of the signals as you are used to do with locally connected SDR’s.
We have a tradition of building multi-tools, so we made sure the SPY Server runs on 32/64bit Windows and Linux on Intel and ARM processors without any compromises. Low cost Raspberry Pi 3 and Odroid boards are in the party.

Technical specifications

HF coverage between DC .. 31 MHz

VHF coverage between 60 .. 260 MHz

-140.0 dBm (0.02 µV / 50 ohms at 15MHz) MDS Typ. at 500Hz bandwidth in HF

-141.5 dBm MDS Typ. at 500 Hz bandwidth in FM Broadcast Band (60 – 108 MHz)

-142.5 dBm MDS Typ. at 500 Hz bandwidth in VHF Aviation Band (118 – 136 MHz)

-140.5 dBm MDS Typ. at 500 Hz bandwidth in VHF Commercial Band (136 – 174 MHz)

-139.0 dBm MDS Typ. at 500 Hz bandwidth in the upper VHF Band (> 174 MHz)

+15 dBm IIP3 on HF at maximum gain

+13 dBm IIP3 on VHF at maximum gain

110 dB blocking dynamic range (BDR) in HF

95 dB blocking dynamic range (BDR) in VHF

150+ dB combined selectivity (hardware + software)

120 dB Image Rejection (software)

Up to 660 kHz alias and image free output for 768 ksps IQ

18 bit Embedded Digital Down Converter (DDC)

22 bit! Resolution at 3 kHz channel using State of the Art DDC (SDR# and SDR-Console)

+10 dBm Maximum RF input

0.5 ppm high precision, low phase noise clock

1 PPB! frequency adjustment capability

Very low phase noise PLL (-110 dBc/Hz @ 1kHz separation @ 100 MHz)

2 x High Dynamic Range Sigma Delta ADCs @ up to 36 MSPS

No Silicon RF switch to introduce IMD in the HF path

Routable RF inputs

Wide Band RF filter bank

Tracking RF filters

Sharp IF filters with 0.1 dB ripple

Smart AGC with real time optimization of the gain distribution

All RF inputs are matched to 50 ohms

4 x Programmable GPIO’s

No drivers required! 100% Plug-and-play on Windows Vista, Seven, 8, 8.1 and 10

Industrial Operating Temperature: -45°C to 85°C

Typical Applications

High Performance Networked HF/VHF Radio

Ham Radio (HF + 2m)

Short Wave Listening (SWL)

AM DX

FM DX

VHF-L TV DX

Remote Telemetry Radio Receiver

Low Bands IoT

Supported Operating Systems

Windows Vista, 7, 8, 8.1 and 10

Linux

*BSD

OSX

Supported Hardware

Intel compatible PC

Raspberry Pi 2 and 3

Odroid C1, C2 and XU4

Many other Single Board Computers (SBC)

Minimum hardware requirements

1GHz Pentium or ARM

1GB of RAM (to run your own OS, HF+ barely needs 1MB of memory)

High speed USB 2.0 controller

Supported Software

Check the download page

Developer API

Open source, multi-platform user mode driver libairspyhf on github

No price point has yet been made public–at least, none that I have discovered. Of course, we’ll post shipping and pricing details when they become available. Follow the tag AirSpy for more. Check out the Airspy website for full details and documentation.

Servosila develops a robot with onboard SDR package

PantronX: Titus II is ready for production

5 Replies

The Titus II portable SDR

(Source: Radio World via Richard Langley)

Titus SDR, a division of PantronX, says the Titus II multi-standard digital radio receiver is ready for production.

The consumer software-defined radio digital receiver platform, which is the result of collaboration between Titus SDR/Patron X, Jasmin-Infotech, TWR, and Fraunhofer IIS, supports multi-standard radio reception, including DRM, DAB and DAB+ and core data applications. The system is based on a custom Android tablet platform, featuring multipoint touch, WiFi/Bluetooth and stereo sound.[…]

Click here to continue reading the full article at Radio World.

Robert’s reviews and how-tos

5 Replies

Like a few of us contributors here on the SWLing Post, Robert Gulley (AK3Q), writes features for The Spectrum Monitor magazine (TSM). Robert and I are both passionate supports of TSM–for a mere $24 per year, you get a monthly digital magazine that is simply chock-full of articles covering all aspects of our radio hobby. A phenomenal value indeed!

I’ve just discovered that Robert has published a number of his past TSM articles–reviews and how-tos–on his excellent blog All Things Radio. Each article can be downloaded as a PDF. Here are the topics:

Using Weak Signal Software to Reach for the Sky! (Part 1)
Using Weak Signal Modes for Propagation, RFI, and Antenna Analysis (Part 2)
Putting My Handheld Antennas to the Test
Going Mobile with Software Defined Radio
Multipsk Software – A Review
TEN-TEC 1253 Build Review

Click here to view and download these articles at All Things Radio.

Thank you, Robert, for sharing these excellent articles with everyone! And many thanks to TSM for allowing its writers second publication rights. Click here to subscribe to The Spectrum Monitor.

Cross Country Wireless release SDR-4+ Special Edition SDR receiver

2 Replies

(Source: Southgate ARC and Kim Elliott)

Cross Country Wireless have released a Special Edition version of their SDR-4+receiver.

This includes many features previously only available in custom versions of the receiver.

Adding a high IP3 push pull RF amplifier, RF filter upgrades and a lower noise and distortion IQ amplifier have resulted in a high performance SDR receiver with an overall IIP3 of +31 dBm.

There is no increase in price for the Special Edition version.

More details on the web page:
http://www.crosscountrywireless.net/sdr-4.htm

SDRs processing Fast Radio Bursts from distant universe

1 Reply

The Green Bank Telescope (Source: NRAO)

Many thanks to SWLing Post contributor, Ed, who shares a link to the following article at Breakthrough Initiatives:

Green Bank Telescope observations of a dwarf galaxy three billion light years away reveal 15 bursts of radio emission. This is the first time bursts from this source have been seen at these frequencies.

San Francisco – August 29, 2017 – Breakthrough Listen – the initiative to find signs of intelligent life in the universe – has detected 15 fast radio bursts emanating from the mysterious “repeater” FRB 121102. Fast radio bursts, or FRBs, are brief, bright pulses of radio emission from distant galaxies. First detected with the Parkes Telescope in Australia, FRBs have now been seen by several radio telescopes around the world. FRB 121102 was discovered in 2012, on November 2nd (hence its name). In 2015, it was the first FRB seen to repeat, ruling out theories of the bursts’ origins that involved the catastrophic destruction of the progenitor (at least in this particular instance). And in 2016, the repeater was the first FRB to have its location pinpointed with sufficient precision to allow its host galaxy to be identified. It resides in a dwarf galaxy about 3 billion light years away from Earth.

Attempts to understand the mechanism that generates FRBs have made this galaxy a target of ongoing monitoring campaigns by instruments across the globe. Possible explanations for FRBs range from outbursts from rotating neutron stars with extremely strong magnetic fields, to more speculative ideas that they are directed energy sources used by extraterrestrial civilizations to power spacecraft.

Breakthrough Listen is a global astronomical initiative launched in 2015 by Internet investor and philanthropist Yuri Milner and cosmologist Stephen Hawking. As part of their program to observe nearby stars and galaxies for signatures of extraterrestrial technology, the Listen science team at UC Berkeley added FRB 121102 to their list of targets. In the early hours of Saturday, August 26, UC Berkeley Postdoctoral Researcher Dr. Vishal Gajjar observed the location of FRB 121102 using the Breakthrough Listen backend instrument at the Green Bank Telescope in West Virginia. The instrument accumulated 400 TB of data on the object over a five hour observation, observing the entire 4 to 8 GHz frequency band.[…]

Analysis by Dr. Gajjar and the Listen team revealed 15 new pulses from FRB 121102. As well as confirming that the source is in a newly active state, the high resolution of the data obtained by the Listen instrument will allow measurement of the properties of these mysterious bursts at a higher precision than ever possible before.

The observations also show for the first time that FRBs emit at higher frequencies (with the brightest emission occurring at around 7 GHz) than previously observed. The extraordinary capabilities of the Listen backend, which is able to record several gigahertz of bandwidth at a time, split into billions of individual channels, enable a new view of the frequency spectrum of FRBs, and should shed additional light on the processes giving rise to FRB emission.
When the recently-detected pulses left their host galaxy our entire Solar System was just 2 billion years old. […]

The new results are reported as an Astronomer’s Telegram at www.astronomerstelegram.org/?read=10675 and will be described in further detail in an upcoming scientific journal article.

Breakthrough Listen is a scientific program in search for evidence of technological life in the Universe. It aims to survey one million nearby stars, the entire galactic plane and 100 nearby galaxies at a wide range of radio and optical bands.[…]

The linked animation shows 14 of the 15 detected bursts in succession, illustrating their dispersed spectrum and extreme variability. Capturing this diverse set of bursts was made possible by the broad bandwidth that can be processed by the Breakthrough Listen backend at the Green Bank Telescope:

https://storage.googleapis.com/frb121102/FRB121102_Cband_GB.gif