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Re: VLF: EbNaut 8270.1, Thursday Mar 10

To: <[email protected]>
Subject: Re: VLF: EbNaut 8270.1, Thursday Mar 10
From: "Markus Vester" <[email protected]>
Date: Sat, 12 Mar 2016 21:05:31 +0100
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References: <[email protected]> <258C4DDB9D264AFB819843A0DCCCEDE8@White> <E4B292C5C3024AD8B87DE3EB5342A92E@White> <[email protected]> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
Thanks for the hint Jim! Hoping to be able to blame Mother Nature rather than my own transmitter, I inspected several MSK traces in DF3LP's valuable archive http://lf-radio.de/cgi-bin/fh/show_wf.cgi?date=16-03-10 (clicking on a trace produces a dB plot for that channel).  Unfortunately (for me), there was no indication of an SID indent on any of them.
 
All the best,
Markus (DF6NM)
  
 

Sent: Friday, March 11, 2016 5:30 PM
Subject: RE: VLF: EbNaut 8270.1, Thursday Mar 10

Paul and Markus,

Nice work!

Given the good phase SNR I looked for X-ray events correlated with the phase
bump at ~ 11:15. There was a ~ C1 event at about 10:20, which I'm guessing
is ruled out by the (very roughly) 55 minute time difference, although I
didn't adjust for your integration time. I checked a another sunlight path
VLF link and didn't see a phase bump in that time period, but the phase
noise on that link was over 20 degrees i.e. inconclusive. An extrapolation
from McRae Thomson 2003 doesn't seem to rule out 20 degrees phase shift for
a C1 event and 1000km path; any thoughts?

73,
Jim AA5BW  

    

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Paul Nicholson
Sent: Thursday, March 10, 2016 2:25 PM
To: [email protected]
Subject: Re: VLF: EbNaut 8270.1, Thursday Mar 10

Markus wrote:

 > Frequency: 8270.100 Hz,
 > start time 09:20:02,
 > 5 characters, 8K19A, 16 bit CRC, 10 second symbols,  > total duration
5120 seconds,  > end time 10:45:22.

An easy decode Eb/N0 = 1.7 dB, BER 34.2% and the phase pattern was -30 -30 0
0.  Carrier -55.8dB in 2.5kHz after sferic blanking.

 >  The message will be repeated 13:00:02 to 14:25:22

Decoded with Eb/N0 = 0.0 dB, BER 36.9%, phase -30 -30 0 0, carrier -56.2dB.

 > Between the two EbNaut sequences (10:45 to 13 UT), I had  > sent a
straight uninterrupted carrier on 8270.0025 Hz.

Flux density and phase in 30 minute 555uHz averages

  10:45 to 11:15  0.069 fT   -70 deg
  11:00 to 11:30  0.067 fT   -53 deg
  11:15 to 11:45  0.075 fT   -71 deg
  11:30 to 12:00  0.083 fT  -107 deg
  11:45 to 12:15  0.082 fT  -115 deg
  12:00 to 12:30  0.084 fT   -71 deg
  12:15 to 12:45  0.126 fT   -65 deg
  12:30 to 13:00  0.151 fT   -72 deg

Flux density and phase in 15 minute 1.1mHz averages

  11:15 to 11:30  0.054 fT   -43 deg
  11:30 to 11:45  0.104 fT   -87 deg
  11:45 to 12:00  0.077 fT  -138 deg
  12:00 to 12:15  0.094 fT   -95 deg
  12:15 to 12:30  0.091 fT   -51 deg
  12:30 to 12:45  0.167 fT   -71 deg
  12:45 to 13:00  0.135 fT   -74 deg

--
Paul Nicholson,
--


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