Hi Ko, Wolfgang, Markus es All.
Ko, thank you for the hint. Gspec is really a fine help. but sri the resolution
is not sufficient measuring 10mHz or less.
may be it is`nt neccessary any more analysing the mark of DCF39 whether there is
a keying in it or not. Markus wrote:
There is no extra narrowband modulation. The widening of the mark spectral
line is simply caused by the normal FSK bursts (200 bd, 340 Hz shift) which
are sent at irregular intervals, at least once in every 12 seconds.
and Wolf(gang) wrote in a direct e-mail:
Leider ist die
Frequenztastung nicht kohärent, d.h. die Phase des "Trägers" bei 138.8300 kHz
kehrt nach dem kurzen Impulspaket nicht zum ursprünglichen Wert zurück.
But when I do compare the DCF A0 (the mark between two bursts) with the A0 of
p.e.Deutsche Welle (A3BC) using SpecLab or Gspec it seems there is something in
the DCF-mark that looks intentionally (phase keying ?) not to be seen on other
A0s.
sri, Markus, but the screenshot does`nt convince me.
sri, Wolfgang, I do not belief in "Kohärenzprobleme".
the simplest would be questioning the staff at DCF. but would one get the truth
out of them ?
I will see my friends at the Radio-Monitoring-Station Itzehoe
(RegTP-Aussenstelle) to solve the problem (I make it my problem) by analysing
the frequenzy using their equipment (I have been member of the staff).
will do it soon. sri at time I`m vy busy doing my job (mayor).
regards
Uwe/dj8wx
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