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Hi Bob, 4000'ers,
The red trace is noise from the
Spectrogram around 74.55 kHz, normalized to 1 Hz:
noise_n(2540,2560)
Note that this noise power includes some junk from
the DCF sidebands.
The green trace is CFH on 73.6
kHz, measured with SpecLab's MSK monitor set to 300 baud:
pam0(1600,MSK300,20,L5).ampl
The noise floor of this detector is about 10 dB
above the red line. Irregularities between 23 and 1 UT are due to interruptions
during my Opera transmissions and manipulations on the antenna.
We find that best
propagation from Halifax occured approximately between 22 and 6:30 UT, with
another weaker period later in the morning. Throughout the night,
there seemed to be hardly any short-term fading on this path.
The blue trace is supposed to
indicate the strength of the Loran line in the spectrogram:
peak_a(2550.5,2550.7)
This line is not strong enough for a
meaningful result. The noise floor is 10 dB below the red line (minus 18 dB for
16 mHz vs 1 Hz noise bandwidth, plus ~ 8 dB for taking the peak
bin from a 0.2 Hz range). In the future, I intend
to replace this trace by a 77.5 kHz monitor for the DCF77
carrier.
Best "73",
Markus (DF6NM in
Nuernberg, JN59NJ)
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