Message-ID: <00cb01c0c45a$3776b0c0$42b21bca@xtr743187>
From: "Vernall" <vernall@xtra.co.nz>
To: rsgb_lf_group@blacksheep.org
References: <3.0.1.16.20010412154807.40773f12@mail.cc.kuleuven.ac.be>
Subject: Re: LF: Bandwidths/Modes
Date: Sat, 14 Apr 2001 08:41:26 +1200
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Rik,

Very interesting on the three types of spectra:

> So far I 'played' with 3 types of modulation : real BPSK, PSK (amplitudes
> enveloped) and what I call 'soft' PSK (gradual phase transitions instead
of
> brute phase jumps).
> The spectra (and and block diagram of the modulator) can be found at :
>
> http://www.qsl.net/on7yd/PSK_TEST/psk_test.htm
>
> It confirms that :
> - BPSK is far too wide to be used with high power on 136kHz (unless you
> live in the middle of nowhere or you just don't care about others)
> - that PSK has the best (most narrow) bandwidth
> - that 'soft' PSK may have some potential as a class-D suitable mode with
> an acceptable bandwidth.

I think it would be useful to include a 4th spectra for CW "on-off keying"
as there is nearly a century of experience with sharing frequencies where
there are finite key clicks.  One criteria is for BPSK bandwidth to be no
more than a same PEP and same data rate CW emission.

73, Bob