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PA2AGA > HDDIG 08.07.00 16:13l 279 Lines 7319 Bytes #-9406 (0) @ EU
BID : HD_2000_181B
Read: GUEST
Subj: HamDigitalDigest 2000/181B
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Sent: 000708/1112Z @:PI8HGL.#ZH1.NLD.EU #:59751 [Den Haag] FBB $:HD_2000_181B
From: PA2AGA@PI8HGL.#ZH1.NLD.EU
To : HDDIG@EU
Date: Fri, 07 Jul 00 21:35:41 MET
Message-Id: <hd_2000_181B>
From: pa2aga@pe1mvx.ampr.org
To: hd_broadcast@pa2aga.ampr.org
X-BBS-Msg-Type: B
"Peter O. Brackett" wrote:
> The only thing that low peak to average ratio signals [constant envelope,
> such as PSK or FSK] have going for them is that they can be efficiently
> amplified by non-linear amplifiers.
That's true of FSK but BPSK has a 3dB S/N advantage over OOK and FSK.
So a 50 watt BPSK system gets through as well as a 200w CW system.
(50w + 3dB) = 100w avg = 200w (peak) CW
--
http://www.mindspring.com/~w6rca
------------------------------
Date: Wed, 5 Jul 2000 06:32:16 -0700
From: "Johnny Rico" <lawdog2@ibm.net>
Subject: CW versus hi speed digital etc.
"Peter O. Brackett" <ab4bc@ix.netcom.com> wrote in message
news:8jtalm$k06$1@nntp9.atl.mindspring.net...
> Gary:
> Gary, tsk, tsk.. *inaudible* PSK-31, heh, heh. Don't give me that
> stuff.... it's anececdotal hearsay based upon non-scientific
observations.
> Most folks "listen" to PSK-31 in a 2.4 kHz bandwidth, in fact you
hear them
> bragging of seeing several simultaneous signals in their digipan
display,
> but hearing nothing, heh,heh.
I did it this weekend both on PSK31 and Pactor 2, using 250 Hz and 500
Hz IF filters respectively.
>
> The reason they don't hear is because they are listening in a 2.4
kHz
> bandwidth which lets in too much noise and interference which drowns
out the
> PSK signals, but the PSK-31 decoder is listening in a 100 Hz
bandwidth
> through it's digital filter [Matched filter, nearly.].
Wrong, see above.
>
> If the human listened in the same bandwidth it would be perfectly
audible.
> Jeesh, give me a break!
Wrong, see above (take as many breaks as you want, just don't expect
me to pay you for them).
>
--
Roger J. Buffington
W6VZV; w6vzv@arrl.net
____________________
Visit my QRZ page: http://www.qrz.com/callsign.html?callsign=w6vzv
Visit my photo page: http://www.photopoint.com/users/U185957.html
"Politicians are the same the world over...
They promise to build bridges, even where there are no rivers."
-- Nikita Khruschev
------------------------------
Date: Wed, 5 Jul 2000 06:29:30 -0700
From: "Johnny Rico" <lawdog2@ibm.net>
Subject: CW versus hi speed digital etc.
"Peter O. Brackett" <ab4bc@ix.netcom.com> wrote in message
news:8jt7i2$86b$1@nntp9.atl.mindspring.net...
>
> The symbol edges ARE uniform. There are only three Morse Code
Symbols, the
> dot, the dash and the space.
Who cares? This newsgroup is about non Morse Code digital modes. It
is tiresome that frequently a discussion about the various merits of
such modes morphs into a discussion of the virtues of Morse--I guess
because the Morse guys feel threatened in some way.
>
> Gary you are entitled to disagree, that's your "right" but that does
not
> make you right!
He is, though.
> Best Regards,
>
> Peter ["CW is digital"] K1PO
>
Roger [ask me if I care about what CW is or isn't] W6VZV
--
Roger J. Buffington
W6VZV; w6vzv@arrl.net
____________________
Visit my QRZ page: http://www.qrz.com/callsign.html?callsign=w6vzv
Visit my photo page: http://www.photopoint.com/users/U185957.html
"Politicians are the same the world over...
They promise to build bridges, even where there are no rivers."
-- Nikita Khruschev
------------------------------
Date: Wed, 5 Jul 2000 09:50:46 -0500
From: "Peter O. Brackett" <ab4bc@ix.netcom.com>
Subject: CW versus hi speed digital etc.
Hey Roger:
Don't want to learn about digital communications by studying one of the
simplest and most efficient scheme's ever invented?
What?
Peter ["CW is digital"] K1PO
"Johnny Rico" <lawdog2@ibm.net> wrote in message
news:39633aaf_4@news1.prserv.net...
>
>
>
> "Peter O. Brackett" <ab4bc@ix.netcom.com> wrote in message
> news:8jt7i2$86b$1@nntp9.atl.mindspring.net...
> >
> > The symbol edges ARE uniform. There are only three Morse Code
> Symbols, the
> > dot, the dash and the space.
>
> Who cares? This newsgroup is about non Morse Code digital modes. It
> is tiresome that frequently a discussion about the various merits of
> such modes morphs into a discussion of the virtues of Morse--I guess
> because the Morse guys feel threatened in some way.
>
> >
> > Gary you are entitled to disagree, that's your "right" but that does
> not
> > make you right!
>
> He is, though.
> > Best Regards,
> >
> > Peter ["CW is digital"] K1PO
> >
>
> Roger [ask me if I care about what CW is or isn't] W6VZV
> --
>
>
> Roger J. Buffington
> W6VZV; w6vzv@arrl.net
> ____________________
>
> Visit my QRZ page: http://www.qrz.com/callsign.html?callsign=w6vzv
> Visit my photo page: http://www.photopoint.com/users/U185957.html
>
> "Politicians are the same the world over...
> They promise to build bridges, even where there are no rivers."
> -- Nikita Khruschev
>
>
>
>
>
------------------------------
Date: Wed, 5 Jul 2000 09:53:08 -0500
From: "Peter O. Brackett" <ab4bc@ix.netcom.com>
Subject: CW versus hi speed digital etc.
Roger:
If you were on 20 meters and you tuned down a few kHz, how many CW signals
would you "see" in those same filter bandwidths?
Peter ["Iambic keying is simpler to learn than touch typing!"] K1PO
"Johnny Rico" <lawdog2@ibm.net> wrote in message
news:39633ab0_4@news1.prserv.net...
>
>
>
> "Peter O. Brackett" <ab4bc@ix.netcom.com> wrote in message
> news:8jtalm$k06$1@nntp9.atl.mindspring.net...
> > Gary:
> > Gary, tsk, tsk.. *inaudible* PSK-31, heh, heh. Don't give me that
> > stuff.... it's anececdotal hearsay based upon non-scientific
> observations.
> > Most folks "listen" to PSK-31 in a 2.4 kHz bandwidth, in fact you
> hear them
> > bragging of seeing several simultaneous signals in their digipan
> display,
> > but hearing nothing, heh,heh.
>
> I did it this weekend both on PSK31 and Pactor 2, using 250 Hz and 500
> Hz IF filters respectively.
>
> >
> > The reason they don't hear is because they are listening in a 2.4
> kHz
> > bandwidth which lets in too much noise and interference which drowns
> out the
> > PSK signals, but the PSK-31 decoder is listening in a 100 Hz
> bandwidth
> > through it's digital filter [Matched filter, nearly.].
>
> Wrong, see above.
>
> >
> > If the human listened in the same bandwidth it would be perfectly
> audible.
> > Jeesh, give me a break!
>
> Wrong, see above (take as many breaks as you want, just don't expect
> me to pay you for them).
> >
> --
>
>
> Roger J. Buffington
> W6VZV; w6vzv@arrl.net
> ____________________
>
> Visit my QRZ page: http://www.qrz.com/callsign.html?callsign=w6vzv
> Visit my photo page: http://www.photopoint.com/users/U185957.html
>
> "Politicians are the same the world over...
> They promise to build bridges, even where there are no rivers."
> -- Nikita Khruschev
>
>
>
>
>
------------------------------
Date: Wed, 5 Jul 2000 09:49:10 -0500
From: "Peter O. Brackett" <ab4bc@ix.netcom.com>
Subject: CW versus hi speed digital etc.
Hamish:
Sorry, I erred in my statement up the thread, and displayed in the "snippet"
below.
[snip]
"> Hamish, the peak to average ratio of Gaussian Noise [As measured by the
> ratio of the mean to the standard deviation.] is certainly not unity, and
it
> is quite high approaching 12 dB or so...
To be continued in digest: hd_2000_181C
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