More about spectrograms


On this page are a number of spectograms from Low Frequency radio signals. Information about spectrograms can be found on the spectrogram page at: You can enlarge the pictures by double-clicking on each picture or select the hyperlink below the picture.

- This page was last updated on: 25-7-99 16:00utc.

 The spectrograms on this page have been made with the following settings:

A) Input scan settings

B) Colour settings


These settings are a little different from the settings on the spectrogram page. The audio power levels for drawing the audio frequency spectrum are now divided in to three groups. Red/yellow are the loudest signals. The blue group are signals below a ceirtain level. The green group are signals -10dB or more below the average noise level  

The first spectrogram shows a radio transmission by the Amateur station DF3LP on 137.678 kHz, received 07:30 UTC on July 25 th 1999. The second audiogram is a transmission by the Amateur station HB9ASB on 137.734 kHz, received 06:45utc on July 25th 1999. 

3) DF3LP


5) Sferics 25jul99.

Image number 5 shows the sferics conditon (lightning strikes) over Europe on july 25th. 1999.

Copyright HTML page including illustrations M.Sanders 1999. Sferics images provided by the Georg Mueller Institute.

Feel free to hyperlink my homepage: Unauthorised downloading, redestribution, mirroring and modifications are prohibited.

Disclaimer: Information on this page may be used only at the sole responsibiltiy and at own risk and free will of the user of the information. By using any information on this page you will automatically and totaly agree with this statement.