The world is full of software-defined radio (SDR), but HackRF One has a rather unique position – thanks to its vast maximum bandwidth of 20 MHz. With an up-converter, this combination covers more than 70 percent of the whole HF range from 3 to 30 MHz. Even better: with proper software you can record and play this enormous band!
However, this stunning bandwidth is achieved by a moderate resolution of 8 bit, resulting in a dynamic range of just nearly 50 dB. Or the half of SDRs like Elad’s FDM-S2.
Anyway. I wanted to know in practice what you can actually do with such a set at a budget price plus mostly free software. The results surprised even me: Properly used, this combination convinced as a quite decent performer on HF! The world map above shows some of the stations received with the set (see insert bottom left) to test its performance.
I laid down my experiences and recommendations for best reception in a paper of 17 multi-media pages full of examples – including 55 screenshots, 21 audio clips and one video. The PDF shows how to optimize reception of broadcast, utility and amateur radio stations. It covers many examples on how to analyze recordings, to decode data transmission with free software plus live decoding of 14 channels in parallel. It also gives some examples of combining HF reception with the internet, e.g. regarding the reception of signals from airplanes (ARINC, HFDL) and vessels (GMDSS).
My experiences really left me enthusiastic about this set.
You may share this enthusiasm and download the PDF of 43 MB here. Save it on your hard disk or USB stick, and open it with a most recent Adobe Reader. Otherwise, the multimedia content will not work.
[Einen deutschsprachigen Test habe ich jeweils als Titelgeschichte in der April- Ausgabe 2017 der Fachzeitschrift Radio-Kurier – weltweit hören und in der Mai-Ausgabe der Fachzeitschrift Funktelegramm veröffentlicht.]
The video shows how to combine some software to get and visualize more information from your HFDL monitoring.
HFDL is a data mode, intensively used between air and ground. You can receive these data and decode it with e.g. PC-HFDL software. These data maybe automatically streamed to software PC-HFDL-Display. It takes up to six sources and displays all information neatly in a spread-sheet style.
If you click on the Flight Number in the resulting spread-sheet, website flightradar24 opens up and shows the complete route of this flight, together with many other data.
Note, that not each and every Flight Number is listed on the flightradar24 page. This page relies mainly on position reports on the ADS-B network, transmitted on 1,090 GHz with a range of rarely more than 400 km. Out of this range, HFDL steps in. ADS-B plus HFDL is a charming combination as is the two software and the web service presented in the above video. Click HD button at bottom right there (“Enable HD Quality”) to get the best quality.
Flight AF 128 from Paris to Beijing: What is the best time/frequency combination to communicate with Stockholm AOCC on HF en route?
HF prediction seems to be a somewhat neglected field among short wave listeners, as well as hams. At the same time, some knowledge of how propagation works on specific paths or into defined areas will greatly enhance your hunting success. If you have considered the somewhat flat learning curve of some software as an obstacle, there now is no excuse. With ASAPS’ recently even more improved online services, you are on the sunny side of HF right now.
I had written a short paper explaining how this free service can be used especially for Utility DXing. If you also ever wanted to know the relation of a waste paper basket and multi path propagation, please download this PDF (7 pages, 22 illustrations) here.
In recent posts, I already wrote about my experiences with Simon Brown’s software SDR Console V3.0. It matches most SDRs, delivers now up to 24 virtual receivers and is capable to run multi instances, i.e. you may run several SDRs on one PC in parallel.
That’s exactly what I did when I connected three SDRs FDM-S2 to a PC, running 35 different ARINC-635 channels in parallel resulting in 68.000 decoded messages. It worked brillantly.
And there is much more, e.g. recording and playing 24 audio channels from broadcasters throughout 20 MHz (the whole FM band!) with hardware RFHack One.
This paper provides a hands-on and step-by-step guide for some vital monitoring tasks like:
- using up to three receivers on one antenna and one PC
- working with multi instances of GUIs
- working with multi instances of software decoders like PC-HFDL and MultiPSK
- carefully planning a monitoring session
- analyzing the decoded results and apply some basic statistics on 68.000+ messages
- record and play 24 channels incl. RDS data within a bandwidth of 20 MHz on the FM broadcast band plus on HF with RFHack One (see screenshot on top of this page, “Matrix” mode)
- … and much more
The original software for Elad receivers provides a very useful feature, resembling the old radio scale: it inserts some station data from a list on their proper place in the spectrum – see screenshots above (utility) and below (broadcast).
You may invoke several lists like EiBi and your own memories. These list just must comply to the data standard, Elad had set. You may also set up your own list. If you sepcify a transmission time other than 0000-2400, only the stations active at this time will pop up.
With Bernd Friedewald’s (DK9FI) International Listening Guide there is such as matching list available providing 31.000+ entries of brodcast as well as of utility stations. Bernd is a long-time professional in the field of broadcast monitoring and international consulting in this field. You may also edit this list.
(Disclaimer: I have no commercial relationship with ILG, and bought the data like everyone.)
24 virtual channels in sizeable windows of 24 kHz width each – also zoomable.
In a sneak preview of his SDR software “SDR Console”, Simon Brown again presented all SDR enthusiasts with again another major achievement: up to 24 independent virtual receivers!
Called “Matrix”, and beautifully layouted, each virtual receiver can be placed within the bandwidth of an SDR, i.e. about 5 MHz using an FDM-S2 by ELAD. Each virtual receiver may carry it’s whole individual settings of e.g. mode, bandwidth and AGC.
I also tried out three instances of this software in parallel with three FDM-S2 to cover 15 MHz with 72 indvidual virtual receivers. Their output may be fed to recorders and/or decoders via virtual audio card.
See this introductory paper for a first view. It shows in praxi how to use this stunning feature to tune into 24 broadcasters in parallel, record and play their transmissions. More to come, e.g. examples with of monitoring with decoders.
The Perseus SDR comes with a software, where you may define up to eight markers. Each of them measures the level of the signal at distances of 100 ms to 5 seconds and writes it into a CSV file. This is the base for further analyzing these data, i.e. propagation. See such an analysis of the fade-out of CHU on 3.330 kHz on top of this page.
With an (active) antenna delivering a constant antenna factor over specific range – as all professional antennas do, e.g. RF-Systems’s DX-1 – you may also switch to logging the field strength of the signal in dBµV, rather than the input level in dBm.
The first paper presents a general introduction into this concept. It has been translated into English by Guy Atkins.
The second paper, in German, goes more into the depth of analyzing the data. But it’s 13 illustrations will make it under stable also to readers who don’t understand German.
FUNcube Dongle PRO is an USB stick, containing a great SDR at a low price of around 200 Euros. It makes a fine choice if you are seeking a serious start into the world of HF & SDRs.
I had much fun in gettingout the most of it regarding the HF bands. My enthusiastic experience resulted in this paper: 16 pages with 43 figures showing how to use this great little SDR in receiving, decoding and analyzing. Many aspects are covered, with broadcast, Amateur Radio and Utility DXing only some of them.
The key success factor in the congested HF bands is shifting the quite limited dynamic range to it’s proper place (see Illustration from the paper on top). This simple technique results in stunning reception of even Decoding delicate digital signals of 2.400 baud out of Tahiti in Germany!
This paper explains in detail on how to get the most out of this receiver.
With “Signals Analyzer”, the late Russian expert Sergey developed an excellent software to analyze digital signals. There still is no better software around to do this job at a budget price.
Signals Analyzer – Step by Step provides a short introduction in using this software with audio recordings.
It is a basic version of a German paper of 28 pages which you will find here. Thanks to its 65 and mostly self-explaining screenshots, it will make an interesting reading also for people who don’t speak “The Awful German Language” (Mark Twain, 1880). Click here to download this enlarged Version.
Google Translate also offers a great help in reading it.
[Deutschsprachige Leser finden eine mit 28 Seiten und 65 Abbildungen ausführlichere Version dieser Einführung in die Analyse-Software “Signals Analyzer” hier.]
Here you find a link to the software and to additional information.
Antonio is one of the most avid users of this software and provides many examples on how to use it on this page.
Monitoring of wide frequency ranges can be an art. And hard work, too. The technique ot the “Living Sonagram” makes this task easy:
- record a frequency range of up to 10 MHz, for e.g. 24 hours or less or more
- define a range of time ad frequency you want to analyze offline
- build up the “Living Sonagram”
- tune. demodulate, and decode in this whole range just with your mouse (see screenshot on top)
You must see this to believe it!
The Software has been developed by Simon Brown.
I wrote this paper as a step-by-step introduction into this technique.
You may also look this video on this topic.