Re: VLF: Night-transmission on 8270.1 Hz

[Markus Vester <markusvester@aol.com>]

Nice nighttime activity! And a very strong signal on our Bavarian grabbers
DL0AO https://vlf.u01.de/
DF6NM http://www.df6nm.de/vlf/vlfgrabber.htm

Unfortunately I discovered that due to low temperatures at the DL0AO site, some SpecLab instances had lost samplerate tracking because the deviation exceeded a +-5 ppm window. The problem was noticed and fixed early into the transmission, but applying the change induced display slips with repetition of some spectrogram columns.

The nighttime peak in Todmorden is truly impressive! Hope that Alex might pick up something as well.

Best 73,
Markus (DF6NM)


Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 19. Jan. 2019 19:50
Betreff: VLF: Night-transmission on 8270.1 Hz

Hi VLF,

Since 18:14 UTC i am transmitting on the ground loop antenna again, this
time on 8270.1 Hz, where RN3AUS is watching from near Moscow! After the
recent very strong signal at SQ5BPF in 976 km distance i like to know if
the signal can make the 2040 km path to Alex as well? It is in the same
direction that SQ5BPF but more than twice the distance. Will this work?
Because the antenna is beaming towards Paul and has its null into the
direction to SQ5BPF and RN3AUS. Anyway the strong signal in Poland...

Now i'm sitting in my car here, the sky is clear, the moon is full and
it is below 0 C here. I have some tea which is still warm, more or less.
The DC measurement at the loop tells it has just 57.5 Ohm at f=0! That
is the lowest value i measured so far.
The accu display tells me: 12.8V, 40.9A, 524 W, 85% rest capacity and
about 2.5 hours rest time left at this power level. I can measure the
antenna current with a Rohde&Schwarz scope using the spectrum analyzer
function. It tells me -6.3 dBV of the fundamental frequency, measured
across a 0.2 Ohm shunt resistor, so that is equal to 2.42 A antenna current.

Unfortunately the frequency is not covered by Paul's excellent grabber.
Maybe he can give some informations about the signal strength? It should
be my strongest signal since the kite experiments in 2011.

The carrier will stay on the air for 2 hours.

Al reports are welcome.

73, Stefan

PS: Feet and tea cold now...