Hello group,
Since yesterday in the afternoon, i'm running a CW beacon again at 137.0
kHz. Speed is about 25 BPM i guess.
It was intended to generate a test signal for my antenna tests here in
the holiday camp in JO41.
After seeing two interesting spots in the DX cluster (
http://www.dxsummit.fi/CustomFilter.aspx?customCount=50&customRange=137
) i decided to run it some days longer, knowing that many LF listeners
can cross the way (=spectrum) and note that there is something going on
in the LF amateur band.
This time i got a mail from Horst/DL2SAV near Stuttgart (JN48 i think).
He gave me a very interesting report. He is using no amateur radio to
receive LF but an old tube radio from the 60's (Schaub-Lorenz) and a
homemade tube Audion. He tells that DCF39 seems to work as the BFO, so
he can hear me in normal AM mode, like a NDB. Today he sent me 3
recordings which sound very fascinating for me. If you want to listen,
here the link:
http://dl.dropbox.com/u/19882028/LF/DK7FC_137kHz_30Apr12_amTag_mit_Audion.mp3
http://dl.dropbox.com/u/19882028/LF/Dk7FC_137kHz_30Apr_12_mit_Radio_Schaub_Lorenz.mp3
http://dl.dropbox.com/u/19882028/LF/DK7FC_137kHz_30_Apr_112_mit_Audiion.mp3
What i don't understand: If DCF39 is the BFO and i am transmitting at
137.0, then the CW sidetone should be 1830 Hz (LSB, 138.83-137.0)? But
the tone from the Audion sounds rather like 800 Hz for me. Maybe someone
has an explanation.
BTW the beacon is stilll on the air...
73, Stefan/DK7FC
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