Re: LF: Re: WSPR Spots

["Graham" <g8fzk@g8fzk.fsnet.co.uk>]

Mark,



I think 'we are looking at situation parallel with the  argument of using 
video enhancement  as evidence in the  judicial system , in that the 
adjacent  pixel decisions do  not  always result in a correct recovery of 
the  original data .. and  over lay filters / masks can be 'biased' I assume 
this is the  case as the  recovered call signs are in a recognisable format 
and not  simply  random data .. ?

> I am coming to the conclusion that the single reported signal level is
> barely adequate on 500KHz, an pretty useless when the QSB is fast.. what
> WSPR software needs for studying propagation is perhaps 10 or 20  sig 
> level
> measurements per period,
Funny  you  should  mention that , this  page was started Nov 2007 , with 
the same in mind !
http://groups.google.co.uk/group/uk500khz/web/the-big-beacon-project

G...

--------------------------------------------------
From: "Mark" <markhughes1@blueyonder.co.uk>
Sent: Saturday, February 21, 2009 8:17 AM
To: <rsgb_lf_group@blacksheep.org>
Subject: LF: Re: WSPR Spots

> Hi all,
> The spurious calls generated here are as a result of a wideband birdie 
> that
> wanders through the 500KHz band, probably a switchmode PSU
> Not all the bad decodes get uploaded, so there would appear to be some
> filtering of what is uploaded
> What the software needs is a checkbox after each decode, so that the user
> can mark bad messages, the system could them automatically remove those 
> from
> the database
>
> I have also been analysing the spots by graphing signal strength, and
> comparing for example my reception of SM5BHZ with that of other stations.
> (for anyone interested I have used an Excel macro to download specified
> spots from the web database, and put them in a formal easy to use with the
> graph wizard)
>
> I am coming to the conclusion that the single reported signal level is
> barely adequate on 500KHz, an pretty useless when the QSB is fast.. what
> WSPR software needs for studying propagation is perhaps 10 or 20  sig 
> level
> measurements per period, just uploaded to the database for future study. 
> I
> have suggested this to Joe, but I think he has higher priorities and 
> no-one
> else has requested anything similar
>
> Regards
> Mark GM4ISM
> www.dc2light.co.uk
>
>
> ----- Original Message ----- 
> From: "Andy Talbot" <andy.g4jnt@googlemail.com>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Friday, February 20, 2009 10:11 PM
> Subject: LF: WSPR Spots
>
>
> > According to the WSPR Spot database, there is some "interesting" DX
> > being received chez GM4ISM.
> > Is there some carrier or coherent  QRM present to generate these false
> > hits?
> >
> > Just got a WSPR generating routine running on a 16F628 PIC with AD9852
> > DDS combination.
> > At the moment it only operates at 100% duty cycle, but I'm Looking at
> > PN sequences for randomised transmission slots with 20/25/33% Duty
> > cycle operation.
> >
> > Andy  G4JNT
> > www.g4jnt.com
>
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