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Re: LF: WSJT-X v0.5 r2786_JT9-10

To: <[email protected]>
Subject: Re: LF: WSJT-X v0.5 r2786_JT9-10
From: "Markus Vester" <[email protected]>
Date: Thu, 29 Nov 2012 23:59:47 +0100
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Hi Graham,
 
of course I would seriously compare modes, based on conveyed bits per transmitted energy, or available radiated power. Of course I'd NEVER EVER dare to compare anything against handmade CW, would I ;-)) 
 
Won't delve into the numbers again. Well you say Opera may be slower but is more robust... Then it's like the farm tractor which can master rumbly ground, while 'JT is the fast train running only on a carefully leveled steel track? ;-) On the other hand I believe there is a lot more potential in the Opera modulation scheme, if only it were be transmitted and received coherently.
 
However looking at my spectrogram with Stefan booming in here, I have to say I'm glad he's currently not using on-off-keying...
 
But after all we're not on a crusade, hence the smileys ;-)  
 
Best 73,
Markus (DF6NM)
 
PS what is "wobbly bob"?
PPS There's also a German dragon which brings luck to those using it. We use the same word "Drachen" for dragon and kite ;-)

From: Graham
Sent: Thursday, November 29, 2012 8:47 PM
Subject: Re: LF: WSJT-X v0.5 r2786_JT9-10

Mk..
 
Are you  seriously  comparing  a time  locked   narrow  frequency   tolerance   MFSK    system with one  based on    a  free running  Manchester  coded    OOK  system , immune  from  Doppler  spread and  capable of  simultaneous  multi  decodes   running  on  standard  ham 'wobbly bob'   equipment ?
 
Not  forgetting  the  'wobbly bob'  system   gives a  average of the  signal  along to the time  line  and not a  peak  (inverted) value , so  direct comparisons  are a  little  misleading  , 
 
Just the  same  as  say  'Long'  means  long  in English   and  Dragon  in Mandarin  and a  English  dragon  breaths  fire  and the  other  one  is  made of  fishes and  brings good  luck ...
 
G: )
 

 
Sent: Thursday, November 29, 2012 5:24 PM
Subject: Re: LF: WSJT-X v0.5 r2786_JT9-10

Stefan,
 
yes, theoretically JT9-10 should work down to SNR -37 dB in 2.5 kHz (which would read -41 dB on the Opera scale ;-)
 
Each of your transmissions has been decoded here. Are you receiving JT9 as well?
 
Best 73,
MArkus (DF6NM)
... 
 
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