Re: LF: MF: EbNaut

[Markus Vester <markusvester@aol.com>]

Congratulations to Paul and Domenico, this is a well deserved cup of tea! 

> Maybe that is the farthest EbNaut on MF so far?
I think so. Actually the other day I had tried hard to decode VO1NA here, but never managed to pull enough of Joe's photons out of the noise.

> The question, is that jitter from my tx or is it propagation?
I'm pretty sure it's propagation. The signals from Italy had similar spread and similar day-to-day variability. LF will be much better in that respect.

> I'm suspicious of the multiplier.
It can't be that bad. Even if there was some phase noise, it would hardly rotate the phase by a cycle or more.  

All the best, enjoy!

73, Markus (DF6NM)



-----Ursprüngliche Mitteilung-----
Von: Paul Nicholson <vlf0403@abelian.org>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 1 Mrz 2016 12:08 am
Betreff: Re: LF: MF: EbNaut

Many thanks Markus and Domenico. I'm really pleased
with that.

I make that about 2022 km. A distance record for me!
Maybe that is the farthest EbNaut on MF so far?

My callsign decodes with Eb/N0 = -0.4 dB determined
from the symbol errors and +1.0 dB from the carrier
strength. Still some discrepancy there.

Data from Markus shows invariably a lower Eb/N0 (higher
BER) than suggested by the carrier S/N. The mode is
not performing as good as it should, and the difference
is expressed in the dB between the two columns

> start car. sym.
> 23:15 10.0 3.9

missing out on over 6dB there. The difference is caused
by phase jitter if the carrier Eb/N0 is greater than the
BER Eb/N0. The other way round would indicate some other
nearby signal in the decoder input band.

The question, is that jitter from my tx or is it propagation?

The signal from EbSynth is good. I'm suspicious of the multiplier.

I think I will have to make up another divider and divide
the signal back down to audio frequency and compare with
the reference. I have a nifty soundcard program for accurately
comparing the phase of two signals of different frequencies.

Now for a celebratory cup of tea. The signal stays
on air until 00:00.

--
Paul Nicholson
--