Stefan Schäfer pisze:
Hello Piotr,
Nice to see that you enjoy the LF receptions :-) Generally its nice to
see new upcoming stations and a never ending interest in LF operation.
Soon, i will be one of the active TX stations with a fixed antenna
too. I am looking forward to this :-)
73, Stefan
Hi Stefan,
First of all i thank you for your response due to my LF reception
reports. Sure, it does not happen very often as i live in a really
hostile environment as far as receiving long waves is concerned.
Nevertheless, i do enjoy every single lf reception even if it is a very
'short' distance ( according to 'standards' established by current
T/A observations, transpacific qso etc...) so i was really happy to see
for the first time Markus,
DF6NM and Gus, SM6BHZ tx'ing in the EU '177 window . I even managed
to set up LF grabber: http://www.toya.net.pl/~mlynarski/ which i
will be switching on ocasionally or upon request.
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 :)
( 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 !
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.
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 .. :)
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 :)
Yours,
Piotr, sq7mpj
qth: Lodz /jo91rs/
|
