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Fortunately the VLF transmission ran smoothly
during the night. I'll leave it on until 9:00 UT today to complete a
24 h period, but will have to shut down and leave the house then.
The antenna current was apparently stable, except
for a ~ 15% reduction sometime between 0:00 and 2:30, presumably due to
environmental tuning changes. The signal got lost in the QRN at DK7FC for a
few hours, but seems to be back now at the original level ~ -110
dB.
Thanks to all who took the
time looking!
Best 73,
Markus (DF6NM)
----- Original Message -----
Sent: Thursday, October 14, 2010 11:45
PM
Subject: VLF: Re: Transmitting on
8970.00x now
Well done Paul - yes the "secret" frequency
is 8970.002. Not sure whether that is really accurate to the last uHz
digit, and if all the phase calculations for samplerate tracking and the
software oscillator are implemented in double precision. There may also be
some phase walk due to antenna tuning drift - in effect I am feeding
a narrow series resonant circuit by a voltage source. During the first couple
of hours, I had readjusted the ferrite plate a few times for
maximum juice, and afterwards simply left it set.
Everything looks fairly stable, and I have gained
enough confidence by now to leave it running through the rest of the
night. We may be able to see more of the interesting diurnal effects. My only
worry is that the blanket which I wrapped around the
coil for acoustic insulation might bedew and start an arc.
Guess I will set up my sleeping place beside the transmitter, so I can see the
coil every time I wake up...
This is not a boring hobby ;-)
73, Markus
----- Original Message -----
Sent: Thursday, October 14, 2010 8:32
PM
Subject: VLF: Re: Transmitting on
8970.00x now
Transmitter is still on now at 18:30, with
stable antenna current and very little wind movement. On Stefan's
grabber, the QRN has been gradually increasing since 16:30 or
so, but interestingly my signal there has also gone up by a
couple of dB. Will try to stay on until local midnight (22 UT) to see if
that trend continues.
73, Markus (DF6NM)
----- Original Message -----
Sent: Thursday, October 14, 2010
11:06 AM
Subject: VLF: Transmitting on
8970.00x now
Dear Paul,
you are doing a fantastic job! This is
absolutely amazing.
If you like there will be more food for
your processors: I have a day off work, and restarted a carrier again at
8:52 UT (Oct 14). Antenna conditions are similar as before,
but with slightly modified coil location and acoustical shielding.
I will not announce the exact frequency beforehand, but it is
within a few mHz from 8970.0 to fit into Stefan's 47 uHz
window.
Good luck to everyone,
Markus
(DF6NM in
JN59NK)
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