Utilities by DJ5HG

The following programs need the Matlab Compiler Runtime (MCR) to be installed.


This little program is a very easy-to-use audio recorder (single button recorder). Push the button to start the record, push the same button to stop it. By default siburec stores the wave-files with the stoptime encoded by ISO 8601 appended to 'rec_' as the filename like 'rec-20120905T130513.wav'. But you also can enter a different path and filename.

Siburec User Interface

The audio examples of the program snrgroups further down here all are recorded by siburec.

Download siburec,zip (2.0 MB)


This program generates groups of CW-characters or digits or groups of English spoken digits. This gererated signal passes a radio-channel simulator with the options 'ideal', 'fading' (different coherence times), or 'aurora' (144 MHz). The received signal then is filtered at a user-chosen bandwidth. This program is well suited to test an operators ability of digging faint signals out of the noise.

SNRGroups User Interface

There is no user guide. But a simple help function is integrated.

Here some audio examples:

CW at good SNR of +6dB, but very fast fading: Download audioexample1 for fast fading (30 sec)

The same type of fading at 0dB: Download audioexample2 for fast fading (30 sec)

CW-EME at -15dB, no fading: Download audioexample1 for CW-EME (30 sec)

The same at -18dB, but slower and lower pitch: Download audioexample2 for CW-EME (30 sec)

aurora, CW at -9dB: Download audioexample1 for weak aurora (30 sec)

The same at 0dB: Download audioexample2 for aurora (30 sec)

aurora, SSB at 0dB: Download audioexample for SSB-aurora (20 sec)

Download program snrgroups.zip (700kB)


A program that generates a map with coast lines and locator grid and markers at all locators present in your ASCII log file. This program is intended to draw the results of VHF-work or higher. The search for worked locators can be restricted to those lines in the log file that contain additional entries like "2004" and "CW" or "2005-01-04". If you search for "Alex" you will get a map of locators of operators worked whos name or city starts with "Alex" or a comment contains that string.

The figure shows the unrestricted search for locators in the 144 MHz meteorscatter log of OH0/DJ5HG (July 2012):

LogMap Typical Result

Download logmap.zip (440 kB)


This program is a help for tuning music instruments. It was programmed within two hours long ago when it was needed in my family. Since then no improvements were made. Take it as it is with help and display in German. It displays the spectrum of the actual sound input. Clicking on one of the notes produces the corresponding tone on the sound output.

Stimmung User Interface

Download stimmung.zip (2.5 MB)

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