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VLF: W4DEX reaching Italy and Germany?

To: "[email protected]" <[email protected]>
Subject: VLF: W4DEX reaching Italy and Germany?
From: Paul Nicholson <[email protected]>
Date: Sun, 14 Dec 2014 11:59:16 +0000
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At Cumiana Italy 44.96N,7.42E run by Renato Romero IK1QFK:

Examining 9177Hz S/N and phase in 1 hour steps (278uHz)

 20:00   2.9dB
 20:30   3.2dB
 transmission started around 21:20
 21:30   6.2dB  -102.3
 22:00   1.8dB
 22:30   6.1dB  -159.4
 23:00   5.3dB   155.1
 23:30   4.1dB   172.9
 00:00   6.4dB   151.8
 00:30   6.4dB  -173.8
 01:00   4.4dB  -174.5
 01:30   6.2dB  -174.0
 02:00   8.9dB  -165.6
 02:30   8.1dB  -161.3
 03:00   6.8dB   151.3
 03:30   9.8dB  -178.6
 transmission ended around 04:30
 05:00   -1.2dB
 06:00   -2.6dB

Undoubtedly a signal there.  The steady phase tells us it is a
properly disciplined source, a spurious signal from an ordinary
xtal source would show lots of drift.  A mains harmonic would
be invisible at this bandwidth (it would just add to background
noise as it drifted by).

So, is it W4DEX?  A repeat test with a small frequency shift
would provide confirmation.   S/N is about right given the
extra 1Mm beyond Todmorden.  Frequency is exact which is
improbable otherwise.  The signal vanishes after Dex switches
off. Signal not present before 21:30, therefore not a harmonic
of Renato's GPS timing system.

S/N is 13.7dB in this 4 hour spectrum:

It is the strongest signal in 23000 neighbouring bins.

With the above, and this one by DL4YHF from the 2nd,

we have two good candidate detections of W4DEX in Europe, awaiting

See Renato's website for lots of articles
about VLF/ELF reception techniques.
Paul Nicholson

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