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Date: Wed, 04 Oct 2017 11:50:40 +0200
From: DK7FC <selberdenken@posteo.de>
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References: <15ee3ca0461-c0d-38c1@webjas-vae239.srv.aolmail.net> <59D49A10.6060606@posteo.de> <0e8c591a-d943-5c50-935f-7cf5b87ad2d5@abelian.org>
In-Reply-To: <0e8c591a-d943-5c50-935f-7cf5b87ad2d5@abelian.org>
Subject: Re: VLF: 300 mA on 6470 Hz
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Hi Paul,

Am 04.10.2017 11:07, schrieb Paul Nicholson:
> You may as well use 8K19A or even 4K15A.
>
> If you look at the big table at the end of
>
>  http://abelian.org/ebnaut/ops.shtml
>
> you can see there's no further improvement in success
> rate for 6 bit payloads (1 char plus zero CRC = 6 bits).
>
> The reason appears to be the payload is simply not long
> enough to make full use of the longer constraint lengths.

OK, so i'm changing to:

*f = 6470.005000 Hz
Start time: 04.October.2017  17:00:00 UTC
Symbol period: 240 s
Characters: 1
CRC bits: 0
Coding 8K19A
Duration: 12h48min
Antenna current: 300 mA*


> For some reason, the signal last night was about 6dB weaker.
Interesting. And for some reason, the signal was much stronger last 
night at SQ5BPF. Did you see it? What could be the reason? Just the 
noise blanker / background QRN?
The message will give you/us and 3rd impression about SNR and phase. A 
10 deg phase variation between last night and the night before seems 
already to be quite high, relative to what we observed at 8270. Maybe we 
will learn a bit about propagation by that.
The 1 char message is for Jacek mainly. The chance for a decode will be 
high i think. Then i thought i try another (daily) 12 char message for 
Jacek before we can try the 100 char message. We've already done quite 
much on that 46 km band, so i wouldn't spend to much time there, 2 weeks 
maybe. Then QSY to 58 km where we can stretch the record list a bit by 
transferring 100 chars to you Paul.

73, Stefan


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Hi Paul, <br>
<br>
Am 04.10.2017 11:07, schrieb Paul Nicholson:
<blockquote cite="mid:0e8c591a-d943-5c50-935f-7cf5b87ad2d5@abelian.org"
 type="cite">You may as well use 8K19A or even 4K15A.
  <br>
  <br>
If you look at the big table at the end of
  <br>
  <br>
 <a class="moz-txt-link-freetext" href="http://abelian.org/ebnaut/ops.shtml">http://abelian.org/ebnaut/ops.shtml</a>
  <br>
  <br>
you can see there's no further improvement in success
  <br>
rate for 6 bit payloads (1 char plus zero CRC = 6 bits).
  <br>
  <br>
The reason appears to be the payload is simply not long
  <br>
enough to make full use of the longer constraint lengths.
  <br>
</blockquote>
<br>
OK, so i'm changing to:<br>
<br>
<b>f = 6470.005000 Hz<br>
Start time: 04.October.2017  17:00:00 UTC<br>
Symbol period: 240 s<br>
Characters: 1<br>
CRC bits: 0<br>
Coding 8K19A<br>
Duration: 12h48min<br>
Antenna current: 300 mA</b><br>
<br>
<br>
<blockquote cite="mid:0e8c591a-d943-5c50-935f-7cf5b87ad2d5@abelian.org"
 type="cite">For some reason, the signal last night was about 6dB
weaker.
  <br>
</blockquote>
Interesting. And for some reason, the signal was much stronger last
night at SQ5BPF. Did you see it? What could be the reason? Just the
noise blanker / background QRN?<br>
The message will give you/us and 3rd impression about SNR and phase. A
10 deg phase variation between last night and the night before seems
already to be quite high, relative to what we observed at 8270. Maybe
we will learn a bit about propagation by that.<br>
The 1 char message is for Jacek mainly. The chance for a decode will be
high i think. Then i thought i try another (daily) 12 char message for
Jacek before we can try the 100 char message. We've already done quite
much on that 46 km band, so i wouldn't spend to much time there, 2
weeks maybe. Then QSY to 58 km where we can stretch the record list a
bit by transferring 100 chars to you Paul.<br>
<br>
73, Stefan<br>
<br>
<br>
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