decline dominant ? #JT65 #PSK31
Andrew O'Brien
I agree with the comments thus far. I also think there is a factor associated with the "robustness" of PSK31 or lack thereof when compared to JT65A. When i try PSk31 with basic wire antennas I frequently lose the contact after a brief exchange of a few sentences . Also, more often than i would like, with PSK31 I work a weak signal only to have another QSO start on top of my desired signal. With JT65 this is much more rare, usually what you first decode is able to hold out for the 2-3 exchanges and less susceptible to QRM . Andy K3UK
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W6IDS <w6ids@...>
Hmmmm. . . . .. .I guess I’ll have to peek into JT65. I sort of shied
away from the “exotics” as
I call them. I try not to clamor for the latest “digital darling”
before everyone drops it for
something else that just appeared. <GRIN>. I’ll keep a clear
head too. . . .
Howard W6IDS
From: Andrew O'Brien
Sent: Tuesday, January 03, 2017 5:28 PM
To: main@digitalradio.groups.io
Subject: Re: [digitalradio] #PSK31 decline #JT65 dominant
? I agree with the comments thus far. I also think there is a factor associated with the "robustness" of PSK31 or lack thereof when compared to JT65A. When i try PSk31 with basic wire antennas I frequently lose the contact after a brief exchange of a few sentences . Also, more often than i would like, with PSK31 I work a weak signal only to have another QSO start on top of my desired signal. With JT65 this is much more rare, usually what you first decode is able to hold out for the 2-3 exchanges and less susceptible to QRM . Andy K3UK
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Graham
Andy, That's quite so, but there is also ,as to exactly what is being compared , psk is free running live qso mode , where the JT system's are beacon , fixed format , psk is susceptible to path phase distortion' rendering the signal undetectable, where as the JT system in there data 'decode' state are mfsk and as such more robust , in correlation, [deep-s] the whole of the Tx is treated as a single 'bit' , this gives additional processing gain , whereas psk requires round -10 -12 dB s/n , mfsk may achieve another -10 dB [ or save x 10 power] , the idea of multi pass , also enables additional - dB's to be achieved. I suppose the split is , beacons, where the detection of the other station is all important , or live qso , where the accuracy of the recovered data payload is paramount ... more concerning , in diminishing 'bandwidth' is the rush to high speed wide system's that are capable of only supporting a single data channel , 73-Graham G0NBD
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