Category Archives: Uncategorized

FAX from Shanghai: Pacific Pressures

This FAX broadcast was new to me and received on December 16, 2019 at 08:20 UTC on 16557,1 kHz. It was transmitted via Shanghai Coastal Radio, presumably directed into the Pacific, of which it shows the 48h surface pressure.

It was demodulated from a 25 MHz wide HF recording over 24 hours. This recording was made with Winradio’s G65DDCe Sigma SDR, connected to an active vertical MegaDipol MD300DX (2 x 5 m), and decoded with Wavecom’s W-Code. The recording was scheduled with software SDRC V3 by Simon Brown, and directed via USB3.1 to a 20TB hard disk, WD Duo Book. The resulting one file was 8TB, format WAV RF64.

It was also played back from this hard disk, also via USB3.1. Doing so, it is most remarkable that this setup worked smoothly without any glitches which would promptly have been seen at such a time-critical mode like this FAX., 120/576. So, this reception is also a proof that one can work smoothly with such ‘big data’ even on a hard disk – and not only on expensive SSDs. A FAX transmission is that sensitive that you even see a very weak echo (best seen of the big vertical black stripe at the right which echoes from around 115° East). This originates from a mixed short/long path reception. The strong short path’ flight time is 28.7ms, whereas the weak long path needed 104.7ms. As one FAX line covers 500ms, you can easily measure the delay of roughly 80ms, almost exactly matching the difference of long and short path.

The screenshot has been left un-retouched.

DARC: Rauswurf von DK8OK "satzungswidrig"

Im Jahre 1992 warf mich der Deutsche Amateur Radio Club e.v. (DARC) in überaus hinterhältiger Weise und ohne jede Vorwarnung aus seinen Reihen. Angeblich, so die Halluzination des damaligen Distriktsvorsitzenden in Niedersachsen, hätte ich dem Verein “geschadet”. Nichts weniger als das – und weder er, noch im weiteren Verlauf des Verfahrens der damalige 1. Vorsitzende des DARC konnten auf Vorhalt selbst vor Gericht auch nur einen einzigen Schaden benennen: alles wirre Gesichte. Denn es waren, im Gegenteil, genau auch diese Leute, die dem Verein und dem Amateurfunk massiv schaden sollten. Er verlor seitdem auch deshalb annähernd die Hälfte seiner Mitglieder und stopfte schon bisher rund eine Million Euro in die Taschen von Spitzenfunktionären. Hier allerdings wurde, natürlich, kein Schaden festgestellt.

Dennoch unterblieb eine immer wieder geforderte Rehabilitierung meiner Person. Der heutige Distriktsvorsitzende Niedersachsen zieht sich darauf zurück, dass “eigentlich” ja der DARC-Gesamtvorstand mich rausgeworfen hätte. Der aber reagiert auf dieses Ersuchen nicht. Seit Jahrzehnten nicht.

Das nun aber tat Dr. Erhard Blersch, DB2TU, als Vorsitzender des DARC-Distriktes Württemberg in seinem Rundspruch vom 22.12.2019. Demnach sei dieser Rauswurf eine (und bei weitem nicht die einzige!) “Leiche im Keller des DARC”. Und, konsequent: “Zeit wird es auch, Nils Schiffhauer, DK8OK, zu rehabilitieren.” Ich hätte “in den letzten Jahren und Jahrzehnten sehr viel Positives für den Amateurfunk geleistet.” DB2TU fasst klipp und klar zusammen:
“Der Ausschluss von Nils war satzungswidrig.”

Das nun lag zwar seit fast 30 Jahren auf selbst der flachsten Stirn. Diese Selbstverständlichkeit aber endlich mal öffentlich eingestanden zu haben, ist innerhalb des DARC nicht nur mutig (Erhard wurde ja nicht nur dafür gemobbt, sondern überhaupt für seinen Einsatz für einen transparenten, modernen und diskriminierungsfreien DARC), sondern könnte auch wieder Bewegung in den “Fall DK8OK” bringen, der eigentlich ein “Fall DARC” ist.

Dass man die damals Verantwortlichen, so sie noch im DARC Mitglied oder gar Ehrenmitglied sind, hierfür mit der “Goldenen Deppenraute mit Brillanten und Antennen” auszeichnen will, ist freilich erst nur ein Gerücht …

GMDSS & Display Launcher: Monitoring seven Channels in parallel


GMDSS-Display reading decoded data streams from seven MultiPSK’s instances in parallel, presenting all information neatly in one database.

GMDSS is a system of ship-coast and coast-ship digital communications on six main HF channels. At an average location in Germany, you will receive about 5000 messages altogether during 24 hours.

In the past, I mostly used the excellent and free YaDD software to decode all channels in parallel (yes, YaDD can be opened in multi instances, each one in a separate folder).

During HFDL monitoring, I came across Mike Simpson’s free software Display Launcher which neatly collects now up to 24 different data streams, coming from up to 24 HFDL channels in a clear database format.
Mike’s software also contains a module called “GMDSS-Display” which now works similar in collecting datastream from up to seven GMDSS data streams, decoded by MultiPSK software.

Yes, also MultiPSK can be opened in many instances, each one in a sperate folder. By this way, it accepts e.g. the audio input of seven different GMDSS channels from an SDR via each different VACs, and decodes each of them.
To do so, the decoded data of each MultiSPK instance has to be backed up regularly:
Configuration -> Regular back-up -> 20 sec
Then, decoded data is automatically written into the appropriate QSO.txt file. This, in turn, is read by GMDSS-Display. Of course you first have to set the paths to guide the software to the appropriate sources.

It takes a bit time of setting it all up, but then you may run this combination until a Windows’ update forces the PC to re-boot 😉

With Mike’s development, you have a unique and mighty tool at hand for a 360° view now also in the field of GMDSS – thank you very much!

Please find below the results of a 24 hours’ session on all seven GMDSS HF channels – coast stations only, automatically drawn onto DX Atlas. All stations received in Germany with SDR FDM-S2 and MD300DX, an active vertical Megadipole of just 2 x 2.5 m of stunning performance.


Received coastal stations on all GMDSS channel/HF during 24 hours in Germany world-wide and …


… those with a focus onto Europe.

TDoA on KiwSDR Net: Direction Finding for All!


Four receivers are nailing Saissac as transmitter site of STANAG 4285 transmission on 12.666,5 kHz on July 16th, 2018, 15:45 UTC.

A dream has become true: direction finding (DF) in the range of 0 to 30 MHz for all! The method is “time difference of arrival”. This is a speaking term, and it works exactly like it says: measuring the different times of arrival of a signal at at least three different receivers and calculating the position of the transmitter.

Base is the net of KiwiSDRs. If connected to GPS, each of this SDRs is able to deliver an I/Q stream with time stamps of a very high resolution. If you compare the recordings of different receivers tuned to the same station at the same time, you will find as slight time difference from receiver to receiver. This is due to the “time of flight” from transmitter to receiver. HF is traveling 300 km per 1 millisecond – so time is distance.

However, you don’t know the absolute transmitting time on transmitters other than time signal stations. So “Time Difference on Arrival”, or TDoA, measures the time differences of arrival. The first step is to compare the I/Q streams to find at which time difference their content does correlate. From these time differences, there are calculated curves onto a map. They cross in that region, where most likely the transmitter is located – see the screenshot at the top which I did to locate the STANAG 4285 transmitter on 12.666,5 kHz.

Due to concept, most reliable results (and, hence: sharp regions where the curves meet) are achieved only with the same propagation mode prevailing at all receiving stations. This is most strictly the case on VLF and long wave, where we mostly have one and stable waveguide-like propagation. But you can achieve also stunning results on HF if you carefully choose the SDRs – see next picture.


Here the broadcast station at Issoudun on 15.320 kHz has been pinpointed by G0EVX, OE5EAN and OZ1BFM receivers at 08:35 UTC. The tip of the arrow points to the actual location, just one kilometer south of the RDoA result [see scale!].

As soon as we approach skywave propagation, you must care for more or less the same propagation mode, of which a one-hop propagation (e.g. 1 x F2) should be preferred. Often even a bit bigger heat map of correlation gives a significant clue from where the transmitter is operating  see next picture.


An even weak and fading CIS12 signal 11.836 kHz (spectrogram at the bottom) has been reliably located on Crimea, Sevastopol area. Hence, it is most likely associated with the Russian Navy there.

The software has been developed by some smart people around Christoph Mayer who also provides detailed information on the concept of this approach on his website. It quickly has become an extension of the KiwiSDR net. This makes it very comfortable to use – if you take care of what is said above.


Utility DX: Some (actually: 1.000+) Logs, June, 2016

Part of the EXCEL list

Part of the EXCEL list

“HF for the pros is stone-dead, isn’t it?” This rather verdict than question is often heard even by hams. If you are telling them how busy the bands really are (as they cannot read about that in their magazines), they are doubting: “But you need professional equipment plus decoding software, worth my Mercedes Benz?”, they are upset by the answer: “Absolutely bullshit. A software-defined radio at 500 US-$ plus some free software will produce thousands of logs!”

Still don’t believe that? Well, here is the first thousand, caught just in the first half of June, 2016. Received with an FDM-S2 receiver at a quadloop of 20 m of circumference. I mostly concentrated on fixed (rather than: mobile) stations and of modes which can be decoded with free software – if they are not even outright SSB or CW.

You can download this log: Logs_EXCEL from where it may easily be opened not only by EXCEL, but also e.g. free LibreOffice.
If I find time, even more logs from the same HF recordings will be added.

I am greatly indebted to the busy and resourceful friends of UDXF for their work, thanks.

Elad’s Radio Scale & ILG: 31.000+ entries


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.)