Re: VLF: EbNaut 8270.1, Sunday Mar 20

[Markus Vester <markusvester@aol.com>]

Paul,

 

maybe the explanation is that with 10 minute averages my signal is just too close to the noise. Plotting your data as complex numbers seems to show a fairly Gaussian distribution around a global average at about -85 degrees. 

 

Working back from the EbNaut result Eb/N0 ~ 2 dB in 3 minutes per net bit, we'd expect only around 7 dB SNR for 10 minutes averages during the morning. In addition, the noise seems to have gone up later in the afternoon. The transmitter was turned off at 18:00 UT.

 

Best 73,
Markus

 

 

 

-----Ursprüngliche Mitteilung-----
Von: Markus Vester <markusvester@aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 20 Mrz 2016 10:17 pm
Betreff: Re: VLF: EbNaut 8270.1, Sunday Mar 20

Thanks Paul for the measurements. Hmm, it's a bit disappointing, especially as I don't know the cause for the variation. From here, it appeared that the PLL was nicely in lock every time I looked, and the traces on the grabbers looked mostly good. For the next transmission I will have to go find an independent means of monitoring the radiated phase.

 

All the best,

Markus (DF6NM)

From: Paul Nicholson

Sent: Sunday, March 20, 2016 9:02 PM

To: rsgb_lf_group@blacksheep.org

Subject: Re: VLF: EbNaut 8270.1, Sunday Mar 20

The phase doesn't look very steady Markus.

Below are 10 minute averages, stepping 5 mins and
the timestamp is the start time of each window.

2016-03-20_10:30:00 0.02 fT  -94.4 deg
2016-03-20_10:35:00 0.06 fT  -68.5 deg
2016-03-20_10:40:00 0.08 fT  -71.1 deg
2016-03-20_10:45:00 0.05 fT  -111.0 deg
2016-03-20_10:50:00 0.08 fT  -97.6 deg
2016-03-20_10:55:00 0.13 fT  -61.4 deg
2016-03-20_11:00:00 0.14 fT  -72.4 deg
2016-03-20_11:05:00 0.15 fT  -100.4 deg
2016-03-20_11:10:00 0.12 fT  -81.4 deg
2016-03-20_11:15:00 0.10 fT  -67.1 deg
2016-03-20_11:20:00 0.10 fT  -83.1 deg
2016-03-20_11:25:00 0.07 fT  -90.7 deg
2016-03-20_11:30:00 0.09 fT  -73.4 deg
2016-03-20_11:35:00 0.12 fT  -82.5 deg
2016-03-20_11:40:00 0.12 fT  -83.6 deg
2016-03-20_11:45:00 0.14 fT  -61.0 deg
2016-03-20_11:50:00 0.13 fT  -74.5 deg
2016-03-20_11:55:00 0.10 fT  -81.5 deg
2016-03-20_12:00:00 0.15 fT  -60.9 deg
2016-03-20_12:05:00 0.16 fT  -58.9 deg
2016-03-20_12:10:00 0.08 fT  -100.7 deg
2016-03-20_12:15:00 0.07 fT  -121.2 deg
2016-03-20_12:20:00 0.09 fT  -81.6 deg
2016-03-20_12:25:00 0.12 fT  -54.6 deg
2016-03-20_12:30:00 0.10 fT  -53.3 deg
2016-03-20_12:35:00 0.05 fT  -86.2 deg
2016-03-20_12:40:00 0.09 fT  -108.8 deg
2016-03-20_12:45:00 0.16 fT  -112.1 deg
2016-03-20_12:50:00 0.05 fT  -68.9 deg
2016-03-20_12:55:00 0.06 fT  -40.0 deg
2016-03-20_13:00:00 0.12 fT  -107.6 deg
2016-03-20_13:05:00 0.17 fT  -88.5 deg
2016-03-20_13:10:00 0.13 fT  -73.3 deg
2016-03-20_13:15:00 0.02 fT  -98.8 deg
2016-03-20_13:20:00 0.05 fT  -66.9 deg
2016-03-20_13:25:00 0.14 fT  -66.9 deg
2016-03-20_13:30:00 0.17 fT  -71.1 deg
2016-03-20_13:35:00 0.15 fT  -91.4 deg
2016-03-20_13:40:00 0.15 fT  -69.4 deg
2016-03-20_13:45:00 0.16 fT  -34.4 deg
2016-03-20_13:50:00 0.04 fT  -52.1 deg
2016-03-20_13:55:00 0.11 fT  -144.5 deg
2016-03-20_14:00:00 0.13 fT  -126.8 deg
2016-03-20_14:05:00 0.10 fT  -119.6 deg
2016-03-20_14:10:00 0.05 fT  -161.1 deg
2016-03-20_14:15:00 0.02 fT  -147.2 deg
2016-03-20_14:20:00 0.08 fT  -80.4 deg
2016-03-20_14:25:00 0.19 fT  -81.8 deg
2016-03-20_14:30:00 0.18 fT  -74.5 deg
2016-03-20_14:35:00 0.14 fT  -75.7 deg
2016-03-20_14:40:00 0.15 fT  -80.7 deg
2016-03-20_14:45:00 0.16 fT  -65.9 deg
2016-03-20_14:50:00 0.13 fT  -37.0 deg
2016-03-20_14:55:00 0.10 fT  -42.4 deg
2016-03-20_15:00:00 0.23 fT  -88.5 deg
2016-03-20_15:05:00 0.21 fT  -76.9 deg
2016-03-20_15:10:00 0.13 fT  -40.4 deg
2016-03-20_15:15:00 0.05 fT  22.2 deg
2016-03-20_15:20:00 0.04 fT  -116.2 deg
2016-03-20_15:25:00 0.11 fT  -97.2 deg
2016-03-20_15:30:00 0.02 fT  -125.0 deg
2016-03-20_15:35:00 0.09 fT  149.4 deg
2016-03-20_15:40:00 0.14 fT  -174.3 deg
2016-03-20_15:45:00 0.12 fT  -121.4 deg
2016-03-20_15:50:00 0.14 fT  -79.7 deg
2016-03-20_15:55:00 0.11 fT  -111.8 deg
2016-03-20_16:00:00 0.11 fT  -126.0 deg
2016-03-20_16:05:00 0.21 fT  -64.0 deg
2016-03-20_16:10:00 0.19 fT  -53.8 deg
2016-03-20_16:15:00 0.07 fT  -116.1 deg
2016-03-20_16:20:00 0.14 fT  -108.8 deg
2016-03-20_16:25:00 0.12 fT  -115.2 deg
2016-03-20_16:30:00 0.18 fT  -127.7 deg
2016-03-20_16:35:00 0.18 fT  -111.0 deg
2016-03-20_16:40:00 0.06 fT  -91.6 deg
2016-03-20_16:45:00 0.04 fT  -95.4 deg
2016-03-20_16:50:00 0.08 fT  -98.5 deg
2016-03-20_16:55:00 0.11 fT  -109.4 deg
2016-03-20_17:00:00 0.15 fT  -130.8 deg
2016-03-20_17:05:00 0.09 fT  -100.9 deg
2016-03-20_17:10:00 0.04 fT  -100.1 deg
2016-03-20_17:15:00 0.03 fT  -167.3 deg
2016-03-20_17:20:00 0.14 fT  -57.3 deg
2016-03-20_17:25:00 0.23 fT  -87.3 deg
2016-03-20_17:30:00 0.12 fT  -115.1 deg
2016-03-20_17:35:00 0.13 fT  -91.2 deg
2016-03-20_17:40:00 0.16 fT  -92.9 deg
2016-03-20_17:45:00 0.06 fT  -110.5 deg
2016-03-20_17:50:00 0.10 fT  146.1 deg
2016-03-20_17:55:00 0.13 fT  84.3 deg
2016-03-20_18:00:00 0.15 fT  30.4 deg

There are times when it settles down for an hour but
then goes off all over the place.
--
Paul Nicholson
--

ReIm_vs_Time.png
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