Date: Tue, 22 Aug 2017 05:43:32 -0400
From: Markus Vester <markusvester@aol.com>
To: rsgb_lf_group@blacksheep.org
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Subject: Re: VLF: Carrier on 4470.005 Hz!
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> but Markus alsways seems to use 20000 which will lead to many false decod=
es if the optimum length would be 9 actually

Yes maybe, but couldn't I just decide a posteriori to ignore any decodes wi=
th rank numbers greater than 9? Can a false decode prevent the appearance o=
f a better-ranked correct one?

Best 73,
Markus

-----Urspr=C3=BCngliche Mitteilung-----=20
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 22. Aug 2017 10:32
Betreff: Re: VLF: Carrier on 4470.005 Hz!


Hi Paul, VLF,

 Am 21.08.2017 18:48, schrieb Paul Nicholson:=20

 > f =3D 4470.005000 Hz=20
 > Start time: 22.August.2017  04:00:00 UTC=20
 > Symbol period: 60 s=20
 > Characters: 5=20
 > CRC bits: 6=20
 > Coding 16K21A=20

 With this transmission, the optimum decoder list length will=20
 be about 40 for a full phase search, or about 120 if you=20
 decide the phase is constant enough to restrict the search=20
 to uniform phases.=20


 Hahaa you changed the calculator website now! ;-) I just wanted to reprodu=
ce the settings, http://abelian.org/ebnaut/calc.php?sndb=3D16&snbws=3D0.000=
031&snmps=3D&code=3D16K21&sp=3D60&crc=3D6&nc=3D5&submit=3DCalculate
 and now i saw other values and two lines describing the optimum list lengt=
h more detailed. That is helpful.
 In my EbNaut decode attempts i used a larger list length than recommended =
in the past but Markus alsways seems to use 20000 which will lead to many f=
alse decodes if the optimum length would be 9 actually. This can be problem=
atic when using 2...3 characters.

 All right now.

 Am 21.08.2017 22:15, schrieb Paul Nicholson:=20

 Two days stacked, 20th+21st 07:00 to 19:00.=20

  http://abelian.org/vlf/tmp/170821b.gif=20

 12.5 dB in 23.1 uHz, a little over 4 sigma.=20

Wow, that peak is so nice and sharp that i decided to run the carrier for a=
nother day so you can stack 3 days. The EbNaut message will then start tomo=
rrow 04:00:00.3 UTC.


 73, Stefan
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<div style=3D"font-size:10pt;font-family:arial,helvetica,sans-serif;color:b=
lack;"><div style=3D"color: black; font-family: arial,helvetica,sans-serif;=
 font-size: 10pt;">&gt; but Markus alsways seems to use 20000 which will le=
ad to many false decodes if the optimum length would be 9 actually<br><br>Y=
es maybe, but couldn't I just decide a posteriori to&nbsp;ignore any decode=
s&nbsp;with rank&nbsp;numbers greater than&nbsp;9?&nbsp;Can&nbsp;a false de=
code prevent the appearance of a&nbsp;better-ranked correct one?<br><br>Bes=
t 73,<br>Markus<br><br>-----Urspr=C3=BCngliche Mitteilung----- <br>Von: DK7=
FC &lt;selberdenken@posteo.de&gt;<br>An: rsgb_lf_group &lt;rsgb_lf_group@bl=
acksheep.org&gt;<br>Verschickt: Di, 22. Aug 2017 10:32<br>Betreff: Re: VLF:=
 Carrier on 4470.005 Hz!<br><br></div>
<div id=3D"AOLMsgPart_2_13c37abb-4119-43bc-b23a-12ec824abd2d">
<div class=3D"aolReplacedBody" text=3D"#000000" bgcolor=3D"#ffffff">
Hi Paul, VLF,<br>
<br>
Am 21.08.2017 18:48, schrieb Paul Nicholson:
<blockquote cite=3D"about:blank"><br>
&gt; f =3D 4470.005000 Hz
  <br>
&gt; Start time: 22.August.2017&nbsp; 04:00:00 UTC
  <br>
&gt; Symbol period: 60 s
  <br>
&gt; Characters: 5
  <br>
&gt; CRC bits: 6
  <br>
&gt; Coding 16K21A
  <br>
  <br>
With this transmission, the optimum decoder list length will
  <br>
be about 40 for a full phase search, or about 120 if you
  <br>
decide the phase is constant enough to restrict the search
  <br>
to uniform phases. <br>
</blockquote>
<br>
Hahaa you changed the calculator website now! ;-) I just wanted to
reproduce the settings,
<a class=3D"aolmail_moz-txt-link-freetext" href=3D"http://abelian.org/ebnau=
t/calc.php?sndb=3D16&amp;snbws=3D0.000031&amp;snmps=3D&amp;code=3D16K21&amp=
;sp=3D60&amp;crc=3D6&amp;nc=3D5&amp;submit=3DCalculate" target=3D"_blank" r=
el=3D"noopener noreferrer">http://abelian.org/ebnaut/calc.php?sndb=3D16&amp=
;snbws=3D0.000031&amp;snmps=3D&amp;code=3D16K21&amp;sp=3D60&amp;crc=3D6&amp=
;nc=3D5&amp;submit=3DCalculate</a><br>
and now i saw other values and two lines describing the optimum list
length more detailed. That is helpful.<br>
In my EbNaut decode attempts i used a larger list length than
recommended in the past but Markus alsways seems to use 20000 which
will lead to many false decodes if the optimum length would be 9
actually. This can be problematic when using 2...3 characters.<br>
<br>
All right now.<br>
<br>
Am 21.08.2017 22:15, schrieb Paul Nicholson:
<blockquote cite=3D"about:blank"> <br>
Two days stacked, 20th+21st 07:00 to 19:00. <br>
  <br>
&nbsp;<a class=3D"aolmail_moz-txt-link-freetext" href=3D"http://abelian.org=
/vlf/tmp/170821b.gif" target=3D"_blank" rel=3D"noopener noreferrer">http://=
abelian.org/vlf/tmp/170821b.gif</a> <br>
  <br>
12.5 dB in 23.1 uHz, a little over 4 sigma.
</blockquote>
<br>
Wow, that peak is so nice and sharp that i decided to run the carrier
for another day so you can stack 3 days. <b>The EbNaut message will
then start tomorrow 04:00:00.3 UTC.</b><br>
<br>
<br>
73, Stefan<br>


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