Date: Thu, 5 Oct 2017 09:19:12 +0200 (CEST)
From: Jacek Lipkowski <sq5bpf@lipkowski.org>
To: rsgb_lf_group@blacksheep.org
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Subject: Re: VLF: 300 mA on 6470 Hz
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Got a decode with good Eb/N0. Message not shown, but confirmed by Stefan.

found rank 0 ber 3.4896e-01 Eb/N0 4.1 M -8.871037960e-01 [x] ps [  0    0    0    0    0]
carrier phase: 1.8 deg
carrier Eb/N0: 6.1 dB
carrier Es/N0: -9.20 dB
carrier S/N: 13.63 dB in 21.7 uHz, -33.00 dB in 1Hz, -66.98 dB in 2.5kHz
elapsed 43


VY 73

Jacek / SQ5BPF

On Wed, 4 Oct 2017, DK7FC wrote:

> Date: Wed, 04 Oct 2017 11:50:40 +0200
> From: DK7FC <selberdenken@posteo.de>
> Reply-To: rsgb_lf_group@blacksheep.org
> To: rsgb_lf_group@blacksheep.org
> Subject: Re: VLF: 300 mA on 6470 Hz
> 
> 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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