Am 11.02.2018 19:05, schrieb Paul Nicholson:
The signal from Markus yesterday measures
E-field 8nV/m and S/N 11.24 dB in 139 uHz.
H-field 0.025 fT but S/N only 3.1 dB.
Obviously the excess noise on H at this frequency is still
there.
Yes, there is a lot to gain! I can't imagine that it's just the stronger
mains hum component in the H field.
Stefan wrote:
> Tomorrow i intend to re-build the system for 4470 Hz and
> like to try a 100 character message
Based on the performance of the last 4470 Hz signal I'd guess
it might be more like 15 to 20 days.
I bet it will not take more than 2 weeks.
Perhaps 50 characters would be better. We'll have to do
something - there's been no new VLF milestones since Jan 19th!
We managed to transfer 100 characters on 8270 Hz / 36 km.
We managed to transfer 100 characters on 6470 Hz / 46 km.
We managed to transfer 100 characters on 5170 Hz / 58 km.
We will manage to transfer 100 characters on 4470 Hz / 67 km :-)
And then, guess what comes next!
That's the series of challenges.
But i have another idea which may be good now, since the nights are
still quite long and the QRN is low. In a next email...
I'm glad you're getting to grips with vlfrx-tools. Do you
have a PC to run it on, or just the Pi?
I use the Pi just for recording and streaming.
I have a PC running ubuntu 16.04 LTS but it is just a dual-core PC with
4+2 GB RAM. The calculations take quite long. I try to get a better PC
in some time.
I've been busy making detailed notes on how to set up and use
a Pi with vlfrx-tools, aimed at the novice. Hopefully have
something to post in the next week or so.
I hope this is of some help for a few people. There are not many who
want to take the time and stress the brain to learn something new, which
is complex in the beginning. For me at least, it took several dozen
hours until I'm slowly leaving the state of an absolute Linux-beginner!
Oh, does anyone use Xming to run X-Windows under M$ Windows?
In the beginning i tried it but it doesn't work here.
And what do
people use on Windows for a SSH client?
I'm using PUTTY. This seems to be most popular. BTW i'm running all my
Raspi's on the command line only. The HUI is not activated. It just
consumes CPU and power resources.
73, Stefan
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