Re: LF: VO1NA - interesting condx

[Domenico IZ7SLZ <iz7slz.domenico@gmail.com>]

Good afternoon ,

these are OPDS detections of last night  at IZ7SLZ in JN80NU:

2015-11-10 05:38:26 VO1NA   5426km 137476.999Hz   2mHz -47.5dBOp  93% 17.0dB
2015-11-10 05:03:25 VO1NA   5426km 137476.999Hz   2mHz -43.9dBOp  99% 17.4dB
2015-11-10 04:28:26 VO1NA   5426km 137476.999Hz   2mHz -43.8dBOp  83% 17.7dB
2015-11-10 02:08:24 VO1NA   5426km 137476.999Hz   2mHz -44.9dBOp  93% 17.1dB
2015-11-10 00:58:22 VO1NA   5426km 137476.999Hz   2mHz -43.1dBOp  93% 18.5dB
2015-11-09 21:15:18 G8HUH   1924km 137456.683Hz   2mHz -39.9dBOp 100% 19.8dB
2015-11-09 21:14:17 G3XDV   1796km 137544.810Hz   3mHz -39.8dBOp 100% 20.6dB
2015-11-09 20:37:43 UW8SM    986km 137514.834Hz 133mHz -37.7dBOp  95% 19.9dB
2015-11-09 20:20:52 G8HUH   1924km 137456.683Hz   3mHz -35.9dBOp  85% 20.9dB
2015-11-09 19:48:59 G3XDV   1796km 137544.812Hz   8mHz -33.1dBOp  85% 21.5dB

Receiver is now steered by a GPS disciplinated oscillator, so, for debugging,  i take the opportunity to run EbNaut-rx using VO1NA signal (OP32 transmission ended at 05:03:25).

As learnt from Markus,  an unmodulated carrier is also a valid message for the Ebnaut decoder, resulting in an all-asterisk output (*******).

Attached files are the screenshots of  EbNaut-rx.exe  and show_rawsyms3a.exe (by DF6NM) showing that an EbNaut decoding at IZ7SLZ  is certainly  possibile.

The error rate of the *** decoded carrier is high because half of the symbols are demodulated during Opera gaps.

73, Domenico / iz7slz

On 10 November 2015 at 15:00, Mike Dennison <mike.dennison@ntlworld.com> wrote:

Very interesting reception of VO1NA last night on 137kHz Opera32.

Firstly, for a long period those stations in the west of the UK
(GW0EZY, G3XKR, G4WGT, G8HUH) seemed to have much better reception
than I did in the south-east. It wasn't my receiver, antenna or QRM,
all was working 100%. Later in the night the situation reversed. It
is not unusual for stations only a short distance apart to experience
quite different reception, but I have never seen it demonstrated so
well. Also, the change was remarkably slow.

Secondly, TF3HZ seemed to have poor reception of VO1NA much of the
night.

Thirdly, there were several double decodes. I presume this indicated
deep QSB.

Lastly, this was one of the very few occasions where the deepest of
the deep searches (the ones with the question marks) actually
produced a 'true' result - these are both partial decodes, at 0044,
and 0332. I know these are 'true' because two items - callsign and
frequency - match up.

I believe there was some interesting fading patterns last night as
well as some Luxemburg effect.

Perhaps something for the propagation boffins. In any case, this
showed the value of Opera in producing data when we in Europe are
asleep!

Thanks to Joe for the signal as usual.

Below is my edited data. I have stripped out the locations to reduce
line length. Note that most stations show Joe as being on or close
to137.477kHz (ie 136.0 + 1.477kHz).

Mike, G3XDV

====================================================

08:38    136 VO1NA de GW0EZY Op32 Deep Search -42 dB 1478.1 Hz
08:33    136 VO1NA de TF3HZ Op32 -36 dB F:13% 1476,9 Hz

07:58    136 VO1NA de G3XDV Op32 -40 dB F:15%
07:58    136 VO1NA de G3XKR Op32 -33 dB F:15%

07:23    136 VO1NA de G3XDV Op32 -34 dB F:22%
07:23    136 VO1NA de G3XKR Op32 -29 dB F:20%

06:48    136 VO1NA de G3XDV Op32 -38 dB F:18%
06:48    136 VO1NA de PA7EY Op32 -38 dB F:9%
06:48    136 VO1NA de G3XKR Op32 -28 dB F:0%

06:13    136 VO1NA de G3XKR Op32 -37 dB F:24%
06:13    136 VO1NA de PA7EY Op32 -38 dB F:7%
06:13    136 VO1NA de G3XDV Op32 -35 dB F:6%

05:38    136 VO1NA de G3XDV Op32 -36 dB F:7%
05:38    136 VO1NA de G3XKR Op32 -37 dB F:15%

05:03    136 VO1NA de G3XKR Op32 -34 dB F:10%

04:32    136 VO1NA de PA7EY Op32 Deep Search -42 dB
04:28    136 VO1NA de G3XDV Op32 -37 dB F:6%

03:57    136 VO1NA de PA7EY Op32 Deep Search ?? -41 dB
03:22    136 VO1NA de G3XDV Op32 Deep Search ?? -41 dB 1476.8 Hz

02:08    136 VO1NA de G3XDV Op32 -39 dB F:19%
02:08    136 VO1NA de PA7EY Op32 -30 dB F:1%
02:08    136 VO1NA de G3XKR Op32 -35 dB F:1%

01:37    136 VO1NA de G3XDV Op32 Deep Search -43 dB  1476.8 Hz
01:33    136 VO1NA de PA7EY Op32 -38 dB F:12%

01:02    136 VO1NA de PA7EY Op32 Deep Search -41 dB
00:58    136 VO1NA de G3XDV Op32 -33 dB F:26%
00:44    136 VO1NA de G3XDV Op32 Deep Search ?? -43 dB 1476.8 Hz

00:27    136 VO1NA de PA7EY Op32 Deep Search -42 dB
00:23    136 VO1NA de G4WGT Op32 -35 dB F:28% 1485.4 Hz


***********  10/11/2015  ***********

23:52    136 VO1NA de G4WGT Op32 Deep Search -42 dB 1485.4 Hz
23:48    136 VO1NA de G3XKR Op32 -37 dB F:15%
23:48    136 VO1NA de GW0EZY Op32 -38 dB F:14% 1478.0 Hz

23:17    136 VO1NA de 2E0ILY Op32 Deep Search -42 dB 1477.0 Hz
23:13    136 VO1NA de TF3HZ Op32 -35 dB F:30%_Ini 1476,9 Hz
23:13    136 VO1NA de GW0EZY Op32 -38 dB F:16%  1478.2 Hz
23:13    136 VO1NA de G4WGT Op32 -39 dB F:5%  1485.4 Hz
23:13    136 VO1NA de TF3HZ Op32 -29 dB F:38%_Ini  1477,0 Hz
23:13    136 VO1NA de G3XKR Op32 -33 dB F:4%

22:42    136 VO1NA de G3XDV Op32 Deep Search -41 dB 1476.8 Hz
22:38    136 VO1NA de GW0EZY Op32 -37 dB F:15% 1478.0 Hz
22:38    136 VO1NA de G3XKR Op32 -34 dB F:9%

22:08    136 VO1NA de TF3HZ Op32 Deep Search -42 dB 1476,9 Hz
22:08    136 VO1NA de GW0EZY Op32 Deep Search -42 dB  1478.0 Hz
22:03    136 VO1NA de G8HUH Op32 -31 dB F:2%
22:03    136 VO1NA de G3XKR Op32 -30 dB F:0%
22:03    136 VO1NA de G3XDV Op32 -39 dB F:8%

VO1NA_EbNaut_decoder.jpg
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Screenshot 2015-11-10 13.28.40.png
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