Re: LF: Coherent BPSK on LF using EbNaut

[Markus Vester <markusvester@aol.com>]

Hi Edgar,

 

yes, sure.

On the RX side, you could use one of your IDC's with a Rubidium-derived LO (eg 125 kHz), and preferably 1pps lock for the SpecLab samplerate.. 

On the TX side, a stable and known frequency is needed. Here in Europe, there's probably DK7FC, IZ7SLZ, and myself, but currently only Stefan would be able to generate a strong enough signal (after rebuilding his LF coil). W1TAG, W1VD, VO1NA and perhaps others might be American candidates.

 

The difficulty is that it's a game of hit and miss: The PSK modulation makes a weak signal completely invisible - there is nothing to synchronize to, and if you haven't successfully decoded the message there is no way of even telling whether the signal was there at all. If one doesn't know a priori when propagation is open, one might waste a lot of energy and time, which would have been better invested in a simple carrier detection or a few visual DFCW dashes. I think that's the main reason why Stefan has yet been reluctant regarding PSK.

 

Best 73,

Markus

 

-----Ursprüngliche Mitteilung-----
Von: edgar <edgarjtwining@virginbroadband.com.au>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 24 Okt 2015 4:02 am
Betreff: Re: LF: Coherent BPSK on LF using EbNaut

Hi Markus,

Is it feasible to try receiving Coherent BPSK at Moonah?

Regards, Edgar
Moonah, Tasmania.