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Stefan, Edgar,
of course I shouldn't have used the term "weakened"
which is quite inappropriate for your signal ;-)
Yes I agree that the little
extra distance would hardly explain the SNR difference
between simultaneous receptions at Moonah and Orford. SNR plots
for DCF and HGA also generally seem lower in Orford (keeping in mind the 10 dB
vs 5 dB/div scales). It looks like daytime
background noise may be a bit higher there, with a slight
increase during uploads indicating a little noise pickup from the PC
or modem. But this is probably irrelevant during nighttime hours
when the band noise is way above the local noise.
My only explanation is that
Orford is located on the Tasmanian east coast, with mountain
ranges in the back somewhat obstructing antenna takeoff towards Eu,
while preferring QRN from the Pacific.
Best
73,
Markus (DF6NM)
Sent: Wednesday, October 09, 2013 11:12 PM
Subject: Re: LF: Signal detection question
Am 09.10.2013 00:12,
schrieb Markus Vester:
[...]
I have been following your experiments with
interest. Looking at the two grabbers, Stefan was sometimes visible in
Moonah but not (or at least not much) in Orford. Not sure whether that's due
to some intrinsic noise in the Orford setup (then you might end up making
things worse by adding in Orford data), or Stefan being weakened by the extra
distance (then Orford data would still be useful to partially null QRN).
Weakened by the
extra distance of 27 km (+ 0.16 %) ?? :-)
No i think i am weakened by some Q
decrease of my loding coil and that building, https://dl.dropboxusercontent.com/u/19882028/20130913_161536.jpg
, which is now built up in 30m distance to the antenna :-(
Seems i will need
a 3 phase PA (already thought about a H bridge out of STW25N95K3
:-) ) if i want to hold the level :-) Let us make a reference test (>=! 200
uV/m) when they finished the buildings and dismantled the cranes...
Or, it is
simply a worse propagation than last year??
73,
Stefan/DK7FC
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