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Hell on 136.

I ran Spectrogram to view the part of the band that Geri was transmitting in and got this excellent copy at the start of the QSO.

Geri seen at G3YXM

Later on the noise came up a bit and made things less clear but still copyable.

Here is Geri's reception of my transmission.

G3YXM seen at DK8KW

It was also nice to get a report from Ko Versteeg, his screenshot of my signal is below.

G3YXM seen at NL9222

I shall have to find out what settings he used to get the very clear copy. You can tell my old IC735 is drifting LF as the message slopes down!

My TX power was about 600W PEP with the antenna in its low (15mtrs high) position due to bad weather. The WAV files producing the text were generated by Markus DF6NM's Qbasic program and played out via the soundcard to the IC735 which has been modified to produce a small amount of RF at 136kHz from the transverter socket. This is then amplified to about 5W by a TDA2030 audio chip which drives the usual Mosfet PA biassed into "linear" mode.

Geri kindly translated the instructions for use of the software into English so that I could set it up. It worked first time, once I'd found an old copy of QBasic!

The bandwidth of the signal as seen here was about 10Hz although this can be altered when the WAV files are generated.

Thanks to DF6NM and DK8KW.

Have a go yourself. Download the software and unzip it into a folder called C:\Hell then you won't have to edit any of the files. There's a readme in there with all the info. (not for those frightened of DOS!)

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