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 <[email protected]>
Reply-To: [email protected]
To: [email protected]
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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