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Message-ID: <3.0.1.16.20020121140458.309f44e0@pb623250.kuleuven.be>
Date: Mon, 21 Jan 2002 14:04:58
To: rsgb_lf_group@blacksheep.org
From: "Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be>
Subject: Re: LF: Re: Questions  about Jason.
In-reply-to: <3C4AF58E.1DBA778B@usa.net>
References: <GLEGLGAGDDGENELKGHIJIEAPDMAA.paulc@snet.net>
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>Rik ON7YD is much expert than me in QRSS speed calculations, but let's try :
>suppose I want to send   CQ DE I2PHD
>Unless my computation is wrong, that amounts to a total of 106 dot lengths,
>so the time needed is the following :
>QRSS3     106 x 3   = 318 seconds, i.e.   5 minutes, 18 seconds
>QRSS10   106 x 10 = 1060 seconds, i.e. 17 minutes, 40 seconds
>QRSS60   106 x 60 = 6360 seconds, i.e. 1 hour, 46 minutes
>Jason         12 characters / 2.5  =  4 minutes, 48 seconds
>
>I leave to Rik the computation for DFCW...

In DFCW it would be a length of 40 dots so :
DFCW3 = 2 min 0 sec
DFCW10 = 6 min 40 sec
DFCW60 = 40 min

If we simplify a bit and assume that SNR is only determined by the
dotlength we would have to compare Jason with QRSS12 or DFCW12 :
QRSS12 = 21 min 12 sec
DFCW12 = 8 min 0 sec
Jason = 4 min 24 sec (I count only 11 characters)

The other way arround, if we want to transmit the text at the same speed as
Jason we would need to use QRSS at 2.5 sec/dot or DFCW at 6.6 sec/dot.
This would make QRSS about 6.8dB and DFCW about 2.6dB inferior to Jason.
In the real world the differences will be a bit less since Jason is using a
larger bandwidth.

73, Rik  ON7YD