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Hi Stefan,
good to see the remote station working nicely
now.
>> but don't see you
...yes you do ;-) There is a slight frequency offset in the
remote grabber which had put me out of your QRSS-30 band. I now
switched to my "heritage" QRG 136172.5 ahem 476172.5 Hz, and voila
there it is, loud and clear.
Currently still on the low Marconi, also about
2 mW EMRP. The relatively strong coupling to the LF
grabber E-field antenna produced some aliases and noise there, which have
been mitigated by a 475 kHz Saugkreis (trap) - same as in old AM radios ;-)
73, Markus
Sent: Friday, June 26, 2015 7:46 PM
Subject: Re: LF: 476.181 kHz from indoor loop
Hi Markus,
Thanks for your DFCW-30 transmission. I can
see you clearly in daytime on my RX in the city! However i can't see you on my
RX is the garden! The remote system seems to run stable now, at least for a
longer time then in the last 3 days :-)
http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_remote_Grabber.html
I
switched between a T antenna and a loop beaming 300/120 deg but don't see you.
It appears that the hill between us is (my garden is on the hill side, the city
antenna is more distant to the hill) actually reducing the SNR. So it also
reduces QRN from the east and favours the west. But i would prefer an
omnidirectional pattern :-/
73, Stefan
Am 24.06.2015 12:11,
schrieb Markus Vester:
I am currently running a DFCW-60 beacon on 476.181 kHz, using
the same 10m^2 indoor transmit loop as previously on LF. With 35 Watts of
RF input, estimated radiated power is around 2
mW, with lobes pointing west and east.
The daytime groundwave signal is visible in the bottom panel of the DK7FC
MF grabber. Going by the CCIR plots for 3 mS/m conductivity, the
groundwave attenuation for this distance would be about 23 dB in excess off
lossless 1/r propagation, resulting in approximately 0.2 uV/m in
Heidelberg.
Best 73,
Markus (DF6NM)
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