Message-ID: <5800E0AE.5080403@posteo.de>
Date: Fri, 14 Oct 2016 15:42:06 +0200
From: DK7FC <selberdenken@posteo.de>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3
MIME-Version: 1.0
To: rsgb_lf_group@blacksheep.org
References: <157b05f2e7d-a71-85cc@webprd-a60.mail.aol.com> <57FC02C5.10700@posteo.de> <57FCA0EC.3000804@abelian.org> <57FCE651.7020809@posteo.de> <57FE04F2.9090208@abelian.org> <57FE4A79.2010904@posteo.de> <57FE907A.6040200@abelian.org> <5800DC5D.2040502@posteo.de>
In-Reply-To: <5800DC5D.2040502@posteo.de>
Subject: Re: VLF: EbNaut transmissions on lower frequencies?, pre-tests: 6.47kHz
Content-Type: multipart/alternative;
 boundary="------------040701060507040707040308"
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Content-Length: 5103
Status: O

This is a multi-part message in MIME format.
--------------040701060507040707040308
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

...another thing about phase stability on the 46km band. Take a look at 
http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html
At night you can see the "local effects", frequency dependent minima and 
maxima of the strength of the QRN. Arround 5:30 UTC (sunrise) these 
effects disappear. The effects could cause strong phase instabilities.
Out best result was 10 characters 8K19A with 100s symbols, i.e. 21 hours 
for the transmission. So it must have been during the night as well. But 
this was May, 20th, so the night was short!
We'll see...

73, Stefan

Am 14.10.2016 15:23, schrieb DK7FC:
> Hi Paul,
>
> Hmmmm, wellll, maybe there are some propagation behaviours on the band 
> that we don't know yet. Could summer work better than winter, despite 
> the higher average QRN levels? Who has the privilege to do 
> private-research on a 'new' band? We!
> So, i started a new message:
>
> *f = 6470.00000 Hz
> Start time: 14.10.2016   13:15:00 UTC
> Symbol length: 60 s
> Characters: 3
> CRC 16
> Coding 8K19A
> Duration: 6h, 56m, 0s*
> *Antenna current: 290 mA (ish)*
>
> The QRN is very high now on VLF. But maybe this just indicates that 
> propagation is better??? The QRN looks like as coming from far away, 
> no local effects (yet).
>
> Any news from the previous tests?
>
> 73, Stefan
>
>
>
>
> Am 12.10.2016 21:35, schrieb Paul Nicholson:
>>
>> > f = 6470.00000 Hz
>> > Start time: 12.10.2016   14:30:00 UTC
>> > Symbol length: 40 s
>> > Characters: 3
>> > CRC 16
>> > Coding 8K19A
>>
>> No decode, just a false hit ' WV' at Eb/N0 = -0.7.
>>
>> Strange.  According to carrier measurements this should
>> be an easy decode at around +3db.
>>
>> More carrier measurements: night signal phase lags daytime
>> by 60 degrees.  Night amplitude is about 0.1 fT.
>>
>> The 16K25A 15 char 140 second message should decode at
>> about Eb/N0 +6dB.   So far no improvement on the partial
>> decodes, next to try is correcting for that 60 deg diurnal.
>>
>> -- 
>> Paul Nicholson
>> -- 
>>

--------------040701060507040707040308
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: 8bit

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
...another thing about phase stability on the 46km band. Take a look at
<a class="moz-txt-link-freetext" href="http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html">http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html</a><br>
At night you can see the "local effects", frequency dependent minima
and maxima of the strength of the QRN. Arround 5:30 UTC (sunrise) these
effects disappear. The effects could cause strong phase instabilities.<br>
Out best result was 10 characters 8K19A with 100s symbols, i.e. 21
hours for the transmission. So it must have been during the night as
well. But this was May, 20th, so the night was short!<br>
We'll see...<br>
<br>
73, Stefan<br>
<br>
Am 14.10.2016 15:23, schrieb DK7FC:
<blockquote cite="mid:5800DC5D.2040502@posteo.de" type="cite">
  <meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
Hi Paul, <br>
  <br>
Hmmmm, wellll, maybe there are some propagation behaviours on the band
that we don't know yet. Could summer work better than winter, despite
the higher average QRN levels? Who has the privilege to do
private-research on a 'new' band? We!<br>
So, i started a new message:<br>
  <br>
  <big><b>f = 6470.00000 Hz<br>
Start time: 14.10.2016   13:15:00 UTC<br>
Symbol length: 60 s<br>
Characters: 3<br>
CRC 16<br>
Coding 8K19A<br>
Duration: 6h, 56m, 0s</b></big><br>
  <big><b>Antenna current: 290 mA (ish)</b></big><br>
  <br>
The QRN is very high now on VLF. But maybe this just indicates that
propagation is better??? The QRN looks like as coming from far away, no
local effects (yet).<br>
  <br>
Any news from the previous tests?<br>
  <br>
73, Stefan<br>
  <br>
  <br>
  <br>
  <br>
Am 12.10.2016 21:35, schrieb Paul Nicholson:
  <blockquote cite="mid:57FE907A.6040200@abelian.org" type="cite"><br>
&gt; f = 6470.00000 Hz <br>
&gt; Start time: 12.10.2016   14:30:00 UTC <br>
&gt; Symbol length: 40 s <br>
&gt; Characters: 3 <br>
&gt; CRC 16 <br>
&gt; Coding 8K19A <br>
    <br>
No decode, just a false hit ' WV' at Eb/N0 = -0.7. <br>
    <br>
Strange.  According to carrier measurements this should <br>
be an easy decode at around +3db. <br>
    <br>
More carrier measurements: night signal phase lags daytime <br>
by 60 degrees.  Night amplitude is about 0.1 fT. <br>
    <br>
The 16K25A 15 char 140 second message should decode at <br>
about Eb/N0 +6dB.   So far no improvement on the partial <br>
decodes, next to try is correcting for that 60 deg diurnal. <br>
    <br>
-- <br>
Paul Nicholson <br>
-- <br>
    <br>
  </blockquote>
</blockquote>
</body>
</html>

--------------040701060507040707040308--