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Hi Jay,
as far as I can see, they are using the "new
RSDN-20 transmission sequence" as shown on www.vlf.it, but with Revda and Seyda off air. Your
recording has two consecutive dashes from Krasnodar (K) and Khabarovsk
(E); Novosibirsk (N) is the most distant from you and not
audible.
The attached image shows the relative phases
of dashes from K and N as seen here, while E was very weak at
that time of day. On 14881, the phase of the second N dash is offset from the
first. It is also switched 180° from frame to frame, which is why it is
sometimes erroneously listed at 0.139 Hz offset. On 11905, one of the K dashes appears purple instead of bright
blue. This is the mysterious modulation, consisting of an arbitrary phase
shift applied to one dash in every ten to thirty frames.
Best 73,
Markus (DF6NM)
RSDN-20 (Alpha) transmission scheme,
noted on 10-03-16 14:30
0
3.6s
+-----------+
15.625Hz
|K E N N . .| 14.881kHz x 20/21
|. N E K . .|
12.649kHz x 17/21
|N . K E . .| 11.905kHz x
16/21
+-----------+
K = Krasnodar (West)
N = Novosibirsk
(Center)
E = Khabarovsk (Far East)
A.) NOVOSIBIRSK 55:45:22.0 N
84:26:52.4 E
B.) KRASNODAR 45:24:17.9 N 38:09:29.0
E
C.) KHABAROVSK 50:04:23.9 N 136:36:24.1 E
D.)
REVDA 68:02:07.8 N 34:41:00.0
E
I.) SEYDA 39:28:16.0 N
62:43:07.3 E
Sent: Friday, January 21, 2011 12:27 AM
Subject: Re: LF: Dream 9 (Alpha check)
Marcus
Do you have current information on the Alpha
signals - sequence vs. location? Normally hear two of the transmitters like this
recorded a few minutes ago on 11905. There's info at vlf.it but not sure it is
up to date. Any info would be appreciated.
Jay W1VD WD2XNS
WD2XGR/2
----- Original Message -----
Sent: Thursday, January 20, 2011 6:04
PM
Subject: Re: LF: Dream 9 (Alpha
check)
A quick receive check is whether you can
actually hear the most distant Alpha transmitter as well,
ie. all three dashes on 11.905 kHz during the evening.
Another test is whether you can occasionally
see -40 dB modulation sidebands in a milliHz-resolution spectrogram.
These appear irregularly (often for a few hours around 6 UT),
and are caused by phase alterations on some of the Krasnodar
dashes. This is probably some sort of coded information, piggybacked on
the navigation system.
Best 73,
Markus (DF6NM)
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