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After a 12 hour countinuous carrier transmission, I
finally switched off Monday 20:00 UT. The signal had been
accurately on 8270.020 Hz, with a few exceptions as indicated
here:
7:55 start,
7:55 - 9:40 freq too low,
10:45 phase jump,
11:50 - 12:10
freq too high,
14:30 phase
jump,
20:00
end.
Reception was again marginally positive at
PA1SDB, very clear at OK2BVG, and reached fullscale SNR in the
Todmorden 278 uHz spectrogram.
Best 73,
Markus (DF6NM)
Sent: Monday, April 08, 2013 4:34 PM
Subject: VLF: Sunday / Monday tests 8270.020 Hz
Hi Peter, LF,
thanks for highlighting my marginal traces in
your screenshots. Yes your start and stop times are correct, the TX was actually
on air from 7:45 to 13:45. I use almost the
same setup as in the earlier experiments on 8970: around 70 watts from a
class-B car-hifi amplifier, and the coil placed in the blue dustbin on
the balcony:
Today I had a day off work so I took the chance for
another round on the same QRG, starting 7:57 UT. I was intending
to target your 47 uHz window but unfortunately I messed up the
samplerate tracking again. First I forgot to restart and reset the "error
integral" after DHO's coffee break, which left the samplerate uncorrected at ~
0.05 ppm low until 10 UT. Then around midday the SUN (sic! ;-) came
around shining on the notebook behind the window, warming up the internal
soundcard crystal enough to exceed the +0.1 ppm tracking limit I had
imposed yesterday. This was fixed at 12:15, and the frequency should have
been ok thereafter. If nothing fails I intend to leave the TX
on until around 16 UT.
Best 73,
Markus (DF6NM)
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