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Date: Fri, 03 Nov 2017 12:07:45 +0100
From: DK7FC <selberdenken@posteo.de>
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Subject: Re: VLF: 300 mA on 5170 Hz
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Hello Paul, VLF,

What a great result again! Many thanks for the decode and detailed 
informations.
As expected, we needed 5 days. That's still quite fast i find. But we 
see it begins to become harder on the way down to DC.

Quite a difference between the SNR of H and E on your side. It becomes 
higher the lower we go in frequency. About 5 dB difference on a good 
day, and more than 5 dB on a noisy day.
It seems to show that propagation on 2970 Hz between us was not as bad 
as concluded, it rather was the missing sensitivity. So now it makes 
hope to get much better results already with the new E field RX and it 
is worth to optimise the H field, as you say.
For the next step downwards i would like to operate in the range between 
4...4.47 kHz, i.e. somewhere near 70 km wavelengh. We already got a 
carrier detection there, between us, but that was with the old E field 
RX, right?

What next? I will move to 8270 Hz again for some time to attempt to 
leave a trace at RC4HAA. That's the plan for the weekend. After that, i 
go back to 5170 Hz, trying to transfer 12 characters (or more) to 
RN3AUS. The move to the range near 4 kHz is planned for the end of December.

73, Stefan

Am 03.11.2017 10:34, schrieb Paul Nicholson:
>
> Stefan wrote:
>
> > f = 5170.1000 Hz
> > Start time: 26.October.2017  18:00:00 UTC (daily)
> > Symbol period: 8 s
> > Characters: 100
> > CRC bits: 16
> > Coding 8K21A
>
> > The transmission starts as announced, just a day late.
>
> > On the 29th and today, the 30th, there was no transmission.
> > The safety function triggered again.
>
> Copied "I LIKE THE 58 KM BAND, WHAT A GREAT PLAYING FIELD!!!
>         ANOTHER STEP DOWN ON THE WAY TO DC. 73 DE DK7FC"
>
> after 5 transmissions stacked.  BER 32.7%, Eb/N0 -0.2 dB, with
> constant reference phase, list rank 312678.  Used combined
> H-field and (new) E-field receivers.
>
> That's a record number of characters for this band.
>
> Individual days and receivers:
>
>         H-field                    (new) E-field
>  27/28  -13.2 dB 178 deg         -8.5 dB 156 deg
>  28/29  -12.8 dB 168 deg         -7.4 dB 171 deg
>
>  31/01  -15.5 dB 170 deg         -8.7 dB 167 deg
>  01/02  -12.8 dB 180 deg         -7.3 dB 168 deg
>  02/03  -16.9 dB 180 deg         -7.4 dB 166 deg
>
> Pretty stable phase and S/N from night to night.
> Consistently better performance from the new E-field rx.
>
> -- 
> Paul Nicholson
> -- 
>