Yes the widening of the spectral line at night is surely related to ionospheric fading. The daytime traces in the 109 uHz spectrogram

seem to be leaning toward the left (apparent downward frequency drift, quadratic phase), which is possibly related to the diurnal depression of the ionospheric ceiling height proportional to solar elevation.

 

Best 73,

Markus (DF6NM)

 

 

-----Ursprüngliche Mitteilung-----
Von: jcraig <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Do, 10 Dez 2015 12:10 am
Betreff: Re: LF: VO1NA - carrier

Oh well, I guess we'll have to try again.

Its nice to see that the carrier, though much weaker, is cleaner than
DFC39. Always happy to get your plots, Markus Paul and Edgar.

The TX was switched off at 1341. TA grabbers showed the path was
still very much open so TX resumed at 1355.

Of the kW going up the feedline, 999 are warming up the back yard
and 1 is being radiated. The PSP xfmr, choke, rectifiers and bleeder
are making the shack nice and cozy.

It would be interesting to estimate how much phase variability is
due to propagation. A GPSDO or Rb standard next?

The high res grabber shows more fuzzies during the night. Is the
ionosphere bouncing around in the dark, increasing the bandwidth?

TX on till 1200 (or later)

TNX & Best 73's
Joe VO1NA 
 
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