Message-ID: <006201c087ac$258064f0$0a00a8c0@ThreeLakes.ca>
From: "Larry Kayser" <kayser@sympatico.ca>
To: rsgb_lf_group@blacksheep.org
References: <4.1.20010125141716.017e5680@pop.tiscalinet.it> <3.0.1.16.20010126104930.2c07643c@mail.cc.kuleuven.ac.be>
Subject: LF: Re: VA3LK seen in ON
Date: Fri, 26 Jan 2001 07:14:04 -0500
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> More general : it seems that it is possible to cross the pond with
stations
> running less than 1W ERP (believe that BMU and AQC are abt 400-500mW) but
> it needs rather long dotlengths (1 minute). So we want to take the next
> step to 2-way communication we might need a more 'time efficient' mode
than
> straight morse code.

Yes, exactly what we on this side are working on.  We have two systems, Bill
de Carle has a BPSK variant that is coherent to a GPS data stream and the 1
Hz ticks fed into a computer parallel port.   I have resurected an FSK
system I used on EME some years ago, more below.

More complicated 'coding' using multiple frequencies
> could even speed up things more, using 4 frequencies we could code 64
> characters in 3 'dots'.
> Based on the experience that a 'very basic' QRSS QSO takes about 20
minutes
> at 3 sec. dotlength this would mean over 6 hours at 1 minute dotlength.

Yes Rik, in fact the 6 hour QSO would be very difficult to make fly with the
minimum character QSO model I am using, about 250 units of data have to be
exchanged.

I studied DFCW and the linear requirement is not possible of course.  So I
have adapted an FSK Model that I used previously for EME from 5 level to a 7
level FSK.  This brings the QSO down to just under 2 hours for callsigns
that are what I call "reasonable", some call signs are painful from a bit
component.  I will write up the minimum QSO model and the 7 Level FSK model
in the near future and let them out on here.  I intend to demo the FSK model
as soon as a I have an DDS Exciter that will listen to a computer serial
port hi.

7 level FSK might sound a bit much but when FSK steps only have to be 50 or
60 milliHz the end effect is not very painful.

Larry
VA3LK