Monthly Archives: September 2015

Code3-32P: A truly professional Decoder – Tested in the real World

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HOKA’s Code3-32P is a truly professional decoder in a price class which will fit into most hobby budgets. Together with Roland Proesch’s Frequency Manager it makes an even stronger companion (with your Perseus SDR) in decoding and analyzing many digimodes.

This paper is an introduction into this decoder. It’s written in German, but 17 illustrations plus Google’s Translator will help you.

Nach wie vor ist der Code3-32P von HOKA ein starker Decoder und ein zuverlässiges Analysewerkzeug für Digimodes zu einem verhältnismäßig kleinen Preis. Zusammen mit dem Frequency Manager von Roland Proesch bildet er ein nochmals stärkeres Gespann (dann gemeinsam mit dem Perseus SDR).

Dieses deutschsprachige PDF bietet auf 18 Seiten eine reich illustrierte Einführung in den Code3-32P – mit Beispielen aus der wirklichen Welt, jenseits des Deutschen Wetterdienstes …

Solar Eclipse 2015: Some signals did improve, some didn’t

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The Solar Eclipse on March 20th, 2015, provided some unique Monitoring opportunities in Europe. It was the first time that broad parts of the spectrum could have been recorded and analyzed even by hams.

I recorded the range from 0 to 2 MHz to analyze the effects of the eclipse on different frequencies: on VLF signals dropped significantly (see the W-shape level of DHO38 on 23,4 kHz above), whereas on medium wave signals did improve.

This paper covers my observations in e.g. 29 illustrations and some audio files.

Caveat: Embedded multimedia content will only work with the most recent version of Adobe`s Acrobat Reader. And you have to save the PDF on your device (hard disk/stick), to make use of these multi-media.

The best Digimodes: Test reveals surprising results

Disturbed

Digital communications with digimodes is a very efficient tool of HF communications. Hams are using RTTY for decades. Since the advent of PSK31 in late 1998, there have been developed a lot of digimodes with special applications in mind. Albeit, RTTY and PSK31 are still very popular.

When I asked myself: “What’s the best mode?”, I couldn’t get a reliable answer. And, really, it depends.

As a result, I made a setup for testing some chat modes on HF channels which are very much different from just flat noisy (AWGN) channels. The results were very much surprising: There are by far better alternatives to RTTY and PSK31 (see table above, reflecting some of the results).

This paper deals with setting up a real-world testbed and presents some results. Anyone is welcomed to replicate the test and/or extend it with other modes. Recent software of W1JHK has made the workflow much easier and faster since then.

FUNcube Dongle PRO: How to get the most out of it, HF-wise

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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.

ARINC & FDM-S2: Three Channels in a Row

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ELAD’s FDM-S2 provides the output of three different channels within a given HF bandwidth of up to nearly 5 MHz. Hence, you may decode these channels in parallel. ARINC’s reporting system of ground and airborne stations is an excellent candidate to show this feature.

This paper is a step-by-step introduction in how to set up the receiver, the virtual audio cables (VAC), decoder, documenting software and Google Earth to show the results on the globe.

You may then easily configure hard&soft for other applications, e.g. the monitoring of GMDSS channels with communications from ship and shore.

Signals Analyzer: How to do it

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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.

Living Sonagram: A revolutionary tool for Monitoring

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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.

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