more on DCF39 signal
Tue, 25 Jan 2000 18:37:30 -0500
"M. Bruno" wrote:
> Hi all,
> in past weekend I experimented monitoring DCF39's signal with Spectran
> (the Beta 2c version seems to work well).
> I receive the sky wave, since the Alps stop the ground wave. The result
> is that the signal has random amplitude and phase, and there is no
> increase in visual S/N decreasing the bandwidth under 0.064 Hz.
> A screenshot of the resulting signal is available. Probably also the
> FSK modulation contributes to the line spreading observed; the other
> tone is well outside my spectrogram, but there seems to be a coincidence
> between data packets and noise +/- 1 Hz around the carrier.
> I also measured the carrier frequency. It is very close to 138830 Hz; the
> error is probably less than 0.1 Hz, so if anyone in the States is able to
> carefully check the received frequency, the identification should be quite
> even without hearing the modulation by data packets.
> 73 - Marco IK1ODO
> Rivalta, ITALY JN35SA (N 45 01' 25.6", E 7 31' 09.4")