Hello Mike, LF,
Nice to hear from you here, the first time for me i think.
Many thanks for the report, also to Terry/GW0EZY. Which receiver do you
use and which CW filter did you choose? How long are you member of the
reflector and what have you done on 137 so far, or what do you plan?
I'm also impressed by the signal here in 200km distance. I just took a
walk in the forest and made a recording and took some captures. From
this location you can see the Netbook, RX and ferrite antenna
http://dl.dropbox.com/u/19882028/LF/FerriteantennaintheforestJO41.jpg
It's very comfortable to have a complete LF receive system in a bagpack,
leight weight and sensitive. It does not need a ground and does not need
to be highly lifted above he ground. Trees are no problem.
DCF39 is 90 dB S/N in 1 Hz NBW,
http://dl.dropbox.com/u/19882028/LF/DCF39aus%20dem%20Sauerland.png (when
the antenna points to DCF)
My own signal is strongest when the loop just cancels out DCF, it is 50
dB S/N in 1 Hz then,
http://dl.dropbox.com/u/19882028/LF/DK7FCaus%20dem%20Sauerland.png I'm
however not sure if the signal peak level is correct due to the keyed
signal...
Unfortunately there were no other LF amateur signals on the band...
73, Stefan/DK7FC
Am 30.04.2012 14:17, schrieb Mike:
Hi Stefan
You have provided me with my first amateur signal on 136 you
are 559 now
1216utc IO90MS09 South Coast England. Perfect copy with a
10m vertical.
73 de Mike G3JVL
-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of
Stefan Schäfer
Sent: 30 April 2012 11:29
To: [email protected]
Subject: LF: 137 kHz SWL report from a tube Audion
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&cust
omRange=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_amT
ag_mit_Audion.mp3
http://dl.dropbox.com/u/19882028/LF/Dk7FC_137kHz_30Apr_12_mi
t_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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