DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=googlemail.com; s=gamma;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :content-type:content-transfer-encoding;
        b=Ahjk7+NIC7F0YW0imzTYw63rXIPTNMtUZaVN2Ow7boOb40Bnp/O2iBzVG8xEwBpPaN
         wHNhku3FWf/ru1FrrCaDFv+HUJMHF2yJCojnvU+kWPWpl9K1yPjLwrtf/TYP6WFwCWjg
         evTf7iUjhqlATlg7YZSsRrJKGiqayqQy2nJC4=
MIME-Version: 1.0
In-Reply-To: <976D046F0BF44B39A9CC91C7306E969B@AGB>
References: <B4B86DC7B7B84F648BB57AF66F5C3BBE@p4>
	 <001c01c97fae$473a2600$0900a8c0@AM>
	 <200901261610460578.3B70C5B6@smtp.wanadoo.fr>
	 <006201c97fcd$5e425b00$0900a8c0@AM>
	 <878CA1EB1E7349DC9464A021BE1B86B0@p4>
	 <976D046F0BF44B39A9CC91C7306E969B@AGB>
Date: Mon, 26 Jan 2009 18:19:00 +0000
Message-ID: <fc7eccec0901261019k4b567d88vfed8bda9145465e4@mail.gmail.com>
From: Andy Talbot <andy.g4jnt@googlemail.com>
To: rsgb_lf_group@blacksheep.org
DomainKey-Status: good (testing) 
Subject: Re: LF: WSPR 502.400 Dial frequency ?
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


Some spectrum plots of the WSPR signal can be seen at

   http://www.g4jnt.com/wspr-spectra/

These were generated at 1500Hz using WSPR.EXE, directly converted to
RF and fed via an attenuator to an SDR-IQ for measuring and displaying
the spectrum.

If we use the widely accepted -40dBc criteria for adjacent channel
spurii, then it is clear the transmission can be centred at up to 10Hz
below the upper band edge.


Andy  G4JNT
www.g4jnt.com



2009/1/26 Graham <g8fzk@g8fzk.fsnet.co.uk>:
>
> Are we to  adopt  502.400 Hz  USB dial frequency for WSPR ?
> With  1500 Hz audio centre band tone.
>
> RF mid band   carrier frequency of  503.900 Hz ?
>
> With 6 hz modulation and phase continues  tone side bands and
> guard band are  not a issue, the band edge is protected?
>
> 504KHz  and its sidebands are actually  x2 of the fundamental
> so  should not present a problem as the 200 Hz slot is in a
> close in, dead zone, there amplitude increasing lower into the band,
> one of the reasons qrss and range testing takes place in this
> 'noisy' zone.
>
> I will add a  note to  the uk500khz group and links in others  with details
> if
> acceptable to widen the reporting base.
>
> Tnx-
>
> Graham
>
> G0NBD
>
>
>
>
>
>
>
>
>
>
>
>
>
>