Re: LF: EbNaut LF test from iz7slz

[Markus Vester <markusvester@aol.com>]

Paul,

 

interesting spectrum... but before ripping the RX apart I would't rule out propagational Doppler. The main component is half a mHz low which seems reasonable after dusk. The companions are a couple of mHz up - maybe a bit fast, but who knows what's possible at these short wavelengths ;-).

 

This is what the signal looked like here. The yellow line is a 438 uHz FFT around 18:49 UT, the zoomed section is 40 mHz wide.

 

Best 73,

Markus

-----Ursprüngliche Mitteilung----- 
Von: Paul Nicholson <vlf0403@abelian.org>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Do, 19 Nov 2015 7:14 pm
Betreff: Re: LF: EbNaut LF test from iz7slz

 

I'm looking at the 30 minute carrier and there's 

obviously a problem 

 

  http://abelian.org/vlf/tmp/151119c.gif 

 

The main peak is off frequency and it's jumping 

around a lot.   Could be a problem with my timing 

system.  It's reporting a max error of around 40nS 

which is only a degree or two.  I'll go check what 

MSF 60kHz and BBC 198 kHz look like. 

 

Best decode of the 18:00 messages was with timing 

offset +60 mS which gave Eb/N0 +2.1dB which is about 

5dB worse than it should be given the carrier strength. 

 

-- 

Paul Nicholson 

-- 

 

EbNautSpectrogram_151119_cursor1849.png
Description: PNG image