AW: Re: VLF: 8269.990Hz

[uwe-jannsen@kabelmail.de]

thanks, Stefan.

the carrier is on the air.
the message:

start 2016-04-13 07:00:00
coding 8K19A
CRC 16
period 30
length 5
duration 04:16:00:00

Have fun agn
Uwe/dj8wx

 

Von: DK7FC <selberdenken@posteo.de>
Gesendet: 11.04.2016 23:42
An: <rsgb_lf_group@blacksheep.org>
Betreff: Re: VLF: 8269.990Hz

 

Uwe, your transmissions are very interesting. I'm looking forward to receive the 5 char message at 30s. We can try 25s symbols later :-)

73, Stefan

Am 11.04.2016 19:05, schrieb uwe-jannsen@kabelmail.de:

Thanks, Paul.

Congrats to Stefan and Markus.

The EbNaut Sender is prepared for length 5, retaining period 30.
But: this afternoon the sky suddenly turned from blue to dark grey, so possibly the TX stays off.

We will see.
Uwe

 

Von: Markus Vester <markusvester@aol.com>
Gesendet: 11.04.2016 18:26
An: <rsgb_lf_group@blacksheep.org>
Betreff: Re: VLF: 8269.990Hz

 

 

Uwe,

 

... me too ;-) I was actually surprised about the successful decode because the nighttime carrier was well visible in Heidelberg but not at all in my spectrogram.

 

Anyway both our decodes were close to the limit, so for the next step I would suggest to try 5 char but stay with 30 sec symbols. Due to the FEC and CRC overhead, going from 3 to 5 characters (1.667 x payload) will increase the total time only by a factor of  1.23 so we already loose 1.32 dB sensitivity. Shortening the symbols from 30 to 20 seconds would cost another 1.76 dB.

 

Thanks for the test!

 

All the best,

Markus (DF6NM)

 

 

-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mo, 11 Apr 2016 2:56 pm
Betreff: Re: VLF: 8269.990Hz
 

Hello Uwe,

Thanks for the VLF transmission. No problem to decode the message! See attachment.
If Markus can decode and no other station wants to try, maybe we can try 20s symbols and 5 characters, your callsign for example :-)

As you probably saw, i saw your carrier on 8269.99 Hz in my 6000 window in the city but not in the forest. Either it is a propagation phenomenon that i don't understand yet or there is still something wrong with the drift calibration. I will today go on the tree again to re-configure the GPS-module and see if this makes a difference...

73, Stefan

Am 10.04.2016 22:30, schrieb uwe-jannsen@kabelmail.de:

the carrier is on the air.
the message:

start 2016-04-11 07:00:00

coding 8K19A

CRC 16

period 30

length 3

duration 03:28:00:00

Have fun
Uwe/dj8wx