Re: AW: AW: Re: LF: 8270Hz

[Laurence KL7 L <hellozerohellozero@hotmail.com>]

Happy new year all.

Uwe - I had a spoiler carrier up in 8270.02 to confirm rx stability for a while

 You'll see the screen bloom. I intend to put up a separate active loop for 8.2kHz when the weather is more tolerable and mod the input match to the original m0bmu amp/filter. 

My limitation are a noisy over head power line some 200m away which I cant mitigate with the present tools. 

Anyone ID the carrier/mod on 29.7kHz? Ive not put the df loop on it yet butit gets stronger at my dusk and fluttery due to solar stuff during the daytime...

Laurence KL7L

Palmer Wasilla Alaska

On Dec 31, 2015, at 2:24 PM, uwe-jannsen@kabelmail.de wrote:

 

Last message was

Start 2015-12-31 21:55:00

The other conditions as mentioned in the last email.

 

Attached wat I received without RX antenna

 

Uwe

Von: uwe-jannsen@kabelmail.de
Gesendet: 31.12.2015 20:05
An: <rsgb_lf_group@blacksheep.org>
Betreff: AW: Re: LF: 8270Hz

 

content of the message:
WX

thanks for analyzing

Uwe
 

Von: Paul Nicholson <vlf0403@abelian.org>
Gesendet: 31.12.2015 18:18
An: <rsgb_lf_group@blacksheep.org>
Betreff: Re: LF: 8270Hz

 

Strong carrier again Uwe,

http://abelian.org/vlf/fbins.shtml#p=1451559600&b=080&s=sp

> At the beginning a message:

> Start 2015-12-29 23:00:00
> Period 10
> Length 2
> Duration 01:01:20:00
> Bits 368

I could not decode anything. The following carrier
measured 18.4 dB in one hour integration and the signal
calculator


http://abelian.org/ebnaut/calc.php?sndb=18.4&snbws=&snmps=3600&code=8K19&sp=10&crc=16&nc=2

says that should give Eb/N0 of about 8dB. When I run the
carrier into the decoder it comes out well

vtraw -oa dj8wx.151229b.vt |
ebnaut -d -p8K19A -r240 -S10 -PS -N2 -v -c1

initial reference phase 76.9 amplitude 2.991e-03
prep [ 0 0 0 0 0]
found rank 0 ber 2.4457e-01 Eb/N0 8.9 M -1.063431501e-01 [**]
ps [ 0 0 0 0 0]
carrier phase: 7.5
carrier Eb/N0: 7.8
carrier S/N: 18.39 dB in 271.7 uHz
elapsed 5

which agrees with the signal calculator.

With that strong signal, the message should have been an easy decode.

So, something is wrong with the modulation or bit clock.
If you tell me the message, I can analyse the signal.

I have been checking for your long carriers in very narrow bandwidth
at Forest VA (distance 6667.7 km) but so far no sign of anything.


--
Paul Nicholson
--
 

<decode 31.12.2015.png>