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

[Roger Lapthorn <rogerlapthorn@gmail.com>]

Mal,

Amateur radio is about self training and experimentation. Surely the exploration of new modes which allow communication with even weaker signal levels is worth study? 

Stefan,

Joe K1JT's reply is encouraging. 

73s

Roger

-- Via my 2.4GHz transceiver --

On 12 Sep 2012, at 14:32, "mal hamilton" <g3kevmal@talktalk.net> wrote:

Circus is a good description

How many more variations do we need with so few operators to go around.

Nice variety show with one operator on QRSS, another on WSPR, another on Slow WSPR, another on OPERA another on PSK another on BPSK another on ROSS and so it goes on

Counting the number of Transmitting amateurs currently on LF es MF it works out at 0.37543 of a Clown for each mode.

John Duffy's CIRCUS can do better than that with at least ONE CLOWN per ACT

g3kev

 

 

----- Original Message -----

From: Graham

To: rsgb_lf_group@blacksheep.org

Sent: Wednesday, September 12, 2012 1:08 PM

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

Well yes  Joe  ( K)  is right,  BPSK  is  better  , but  needs  a linear  system to  transmit  .... Joe (EA)  has  stated  , he could  extract  another  6  dB  if the  modulation  system  was  changed ......but that's   no longer  Op-ook a  fsk return to  zero, as in some  modes   is  not bpsk  ,

 

As Jim's  published  design  shows  its possible to  add  a  modulator  to a  class e amp , by  envelope  restoration ,

 

WLOF  is  already  coded  and makes use of  multi pass  to  gain s/n  , but  is  psk and  needs  a liner system ...and is  not a   one-pass  decode  system , when  the  s/n is  low .but  at  -41 dB , by what  ever scale  , OP32 is well  into  the  noise  in single pass ?

 

Which is  back to  where  we  started .....

 

But  as Laurence's   'Pesky Protons'   go and play  somewhere  else , then  we all  have a  ring  side seat  for   Stefan's  'Flying Circus'  at least over this  winter !

 

G..

 

 

From: Stefan SchÀfer

Sent: Wednesday, September 12, 2012 1:40 PM

To: rsgb_lf_group@blacksheep.org ; Edgar J Twining

Subject: 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 SchÀfer <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