LF: RE: Fwd: Re: Ideas for a slower WSPR for the 137 khz band

[Rik Strobbe <Rik.Strobbe@fys.kuleuven.be>]

Hello Stefan,

 

BPSK or evn QPSK might be a good choise for daytime 136kHz propagation (surface wave) or 9kHz where paths are indeed stable.

But for nighttime 136kHz and certainly 475/500kHz FSK  seems the better choise. Certainly on 475/500kHz where the very deep QSB is typical at night. It would surprise me that the extreme propagation changes would not affect the phase of the signal.

 

73, Rik  ON7YD - OR7T

 

---

Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens Stefan Schäfer [Stefan.Schaefer@iup.uni-heidelberg.de]
Verzonden: woensdag 12 september 2012 14:40
To: rsgb_lf_group@blacksheep.org; Edgar J Twining
Onderwerp: LF: Fwd: Re: Ideas for a slower WSPR for the 137 khz band

Message from Joe/K1JT.

BTW i don't know if it is OK for Joe that his email is forwarded to everyone in the web! But i think it would be OK for him to forward it to a limited number of active radio amateurs operating in the 137 kHz band. So if you make this email public in the web, it is your decision!

73, Stefan/DK7FC

-------- Original-Nachricht --------

Betreff:	Re: Ideas for a slower WSPR for the 137 khz band
Datum:	Wed, 12 Sep 2012 08:28:47 -0400
Von:	Joe Taylor <joe@Princeton.EDU>
An:	Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>

Hi Stefan,

Thanks for your interesting message.

A super-slow version of WSPR (or something like WSPR) should be 
possible, and I might be able to devote some time to writing the 
necessary code.  You should know that I will not be able to get to it 
for several months, however.  Perhaps near the end of this year.

One question for you: It seems to me that propagation at 137 kHz (and 
possibly also 475 kHz) is generally stable enough to make very slow BPSK 
a better modulation scheme than the 4-FSK used in today's WSPR.  Do you 
agree?

	-- 73, Joe, K1JT