Hello Piotr,
Thanks for your kind words.
Below some comments:
Am 30.12.2010 00:10, schrieb Piotr Mlynarski:
I even managed to set up LF grabber:
http://www.toya.net.pl/~mlynarski/ which i will be switching on
ocasionally or upon request.
Maybe you can add your locator to this website so that people know where
the RX is located ;-)
you may regard this as a 'lower bound' of RX observations i.e. if
something is seen on my grabber it means whole world is already
watching this :)
A "high distance" is very relative, on VLF even much more! For some, 100
km is nothing, for others on LF 200 km would be an exciting record!
Above 600 km is not bad i think and NM / 5 / BHZ is well readable on
your grabber! Congrats to that!
( btw , abt 21 utc.. Markus started TX'ing as i can see veeeery weak
traces at 136.1775 kHz )
the distance to Markus is abt 640 km , to Gus abt 817 km so when you
will be qrv on 137 frm Heidelberg ( 801 km ) i am pretty sure that ,
on statistical average, i will be in position to receive your signal,
so likely,
we may have a x-band qso on 137 kHz - it would be a great pleasure for
me if this would have happened !
OK :-) Are you QRV on 30m? There we could do the crossband QSO. I prefer
30m instead of 40m since there are no nerving contests! ;-) I remember
that RN3AGC and OH5UFO reported that i was audible on 137 last year with
the 100m antenna so it should be no problem to do it in CW.
I am planning to build a /m 137 kHz RX station by using my /p RX and a
magnet foot antenna for GSM which i prepare with the first stage of the
active antenna. This should allow me to easily receive 137 kHz while
driving the car! Hopefully there is not to much QRM during engine is
running. So maybe i can try a crossband QSO with DF6NM TXing on 137 and
me answering on 30m while beeing on the highway :-) This is the plan!
on VLF issues.... just today, Ken, M0KHW asked you abt possible
replacement of bf862 jfet. i can confirm your answer that J310 also
works in your VLF antenna - i have already built it and tested
shortly during
Christmas Eve SAQ transmission - it worked but i had too much qrm so
i it had to be replaced by the loop which nulled some of the qrm. Of
course, the placement of the antenna ( i.e. on my balkony) was
absolutely inappropriate but i did it only for checking purposes
etc... i have also used your idea of separating jfet along with 1M,
10M R's and 20nF cap into a waterproof box while placing the remaining
parts in a separate box and used abt 20 m of pair cable between.
4X1RF has installed his VLF antenna on the balcony as well, using the
same design. So it is obviously possible to get a good reception anyway
;-) Of course it depends on your local noise situation but maybe this
can be improved using some EMC tricks ;-)
i am preparing for your next kite vlf experiment but this time i will
be /p station abt 10 km away frm my qth so i will try to check if
the numerical model of earth-ionosphere waveguide works in practice .. :)
Fine :-) I hope you will achieve some useful data. You know, best is to
record the whole procedure. If you add the MSKs into the recording
(means sampling at 48 kS/s or above) you have a good reference to lock
on, later.
F4DTL was outside in the cold during my last VLF experiment and sent me
one of the best receptions i ever saw from a distance above 450 km,
about 30 dB SNR. So going out into the field seems to promise much. 30
dB in DFCW-600 means that he could receive me in DFCW-10 as well, which
allows doing a xband QSO LF/VLF :-) That would be very exciting on that
distance! Many goals for 2011 ;-)
i plan to use your VLF active antenna along with the SDR-IQ receiver .
At this moment i have completely no idea how to make 'the calibration'
of such setup in order to have the readouts comparable with some
theoretical predictions
but the 'long winter evenings', hopefully, will provide some
solutions :)
You will do the job ;-)
Best 73 and all the best for 2011!
Stefan/DK7FC
Yours,
Piotr, sq7mpj
qth: Lodz /jo91rs/
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