From: "jannsen" <0482183881-0001@t-online.de>
To: rsgb_lf_group@blacksheep.org
References: <5.1.0.14.0.20020108111413.00a6cdf0@gemini.herts.ac.uk>
Subject: Re: LF: RE: GPS Coherent PSK Transmission / Mystery signal
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Date: Tue, 8 Jan 2002 19:56:16 +0100
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James Moritz schrieb:
> Dear LF Group,
>
> Got G4JNT's PSK signal sequence again, quite straightforward once I had 
> figured out it was 30 bits long. The spectrogram method is definitely 
> easier than the oscilloscope phase comparison since you don't have to watch 
> it constantly. The phase transitions are quite clear so long as the signal 
> is strong enough compared to the streaks caused by QRN - I used Spectrum 
> Lab with a resolution of about 0.04Hz (ie what I would use for QRSS30 
> reception). With this, the signal appears as a steady line with a series of 
> "beads" on it corresponding to the phase transitions - think of a strong 
> QRSS signal, then fill in the spaces between dots with a carrier and you 
> get the idea. Wider resolution(ie shorter dot lengths) shows the 
> transitions more sharply if the signal is strong enough, but higher 
> resolution blurs the transitions too much.The display lags behind the 
> actual phase transitions by about 10 or 15s - I suppose it takes this long 
> for the FFT data to accumulate.
>
> I also investigated the "south coast mystery signal" - I got a carrier on 
> 136646.7Hz, drifting perhaps 0.1Hz low overnight. The bearing obtained with 
> a loop was roughly 55/235 degrees - which on my map is a line through my 
> QTH passing through Lowestoft to the NE, and Dorchester to the SW. The 
> signal level did not change by more than a couple of dB between night and 
> morning, so probably not a DX signal.
>
> Cheers, Jim Moritz
> 73 de M0BMU
>
>
Hi Jim,
are ur SpecLab screenshots of the PSK signs somewhere in the internet?
case not, can u send it to my Email adr?

regards
Uwe/dj8wx dj8wx@qsl.net