Date: Wed, 17 Dec 2008 08:49:03 +0100
To: rsgb_lf_group@blacksheep.org
From: Rik Strobbe <rik.strobbe@fys.kuleuven.be>
In-Reply-To: <49482306.2010007@telia.com>
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Subject: Re: LF: RE: Re: whisper
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Hello Johan,

interesting.
Are the specifications of WSPR (coding scheme, shifts etc ..) 
somewhere available ?

73, Rik  ON7YD - OR7T

At 22:52 16/12/2008, you wrote:
>Rik Strobbe wrote:
> > if I got it right WSPR is a 4-FSK mode and does not require linear
> > amplification.
>
>Correct, and, according to Joe K1JT, a "FSK tone accuracy" of 0.1Hz or
>so is enough to not compromise performance too much (FSK tone spacing is
>~1.46Hz). The QRP minded can easily achieve this accuracy with a simple
>VCXO which Peter DL6NL has shown with his PC-less WSPR beacon which has
>been on the air 7*24h for half a year on 30 meters. He is using a PIC
>microcontroller together with a QRPp TX of his own design. A simple PIC
>based WSPR beacon controller for VCXO or AD9850 DDS can be found here:
>
>   http://web.telia.com/~u33233109/mept_jt/mjb002.zip
>
>The current version transmits WSPR modulation only but the firmware can
>easily be modified to insert traditional CW IDs at regular intervals to
>enable reception at such remote places as a misspelled Scraborough.
>
>73 Johan SM6LKM


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