Message-ID: <003f01c98094$f29a1870$0301a8c0@mal769a60aa920>
From: "mal hamilton" <g3kevmal@talktalk.net>
To: <rsgb_lf_group@blacksheep.org>
References: <20090126225342.5af9e594@lurcher>	<459DB6156FCD43509AAB5F5D7282462C@AGB> <20090126232813.551c6bfc@lurcher> <497ECDA6.2060105@telia.com> <009801c98065$18787710$0301a8c0@mal769a60aa920> <497EE52C.4050808@sighthound.demon.co.uk>
Date: Tue, 27 Jan 2009 15:35:56 -0000
MIME-Version: 1.0
Subject: Re: LF: G0NBD difficult to decode
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----- Original Message ----- 
From: "John P-G" <gm4slv@sighthound.demon.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: Tuesday, January 27, 2009 10:42 AM
Subject: Re: LF: G0NBD difficult to decode


> mal hamilton wrote:
>> Johan
>> I have mentioned this several times before but noone seems to know why
>> strong signals or any visible signals do not DECODE. I get some decodes
>> therefore I know my system is working but not sure whether the problem is 
>> at
>> the TX or RX end. To me wspr seems unreliable given the strength of 
>> signals
>> but producing only marginal decoded output.
>> 73 de mal/gkev
>>
>
>
> Mal, LF,
>
> In general WSPR is very good at decoding weak signals - that's what it's
> all about after all - and can give reliable decodes on signals that are
> inaudible and only faintly visible on the waterfall. Occasionally there
> seem to be certain strong signals that won't decode, when weaker signals
> from the same stations are fine.
>
> Some discussion has taken place on the WSPR forum over incompatible
> soundcard sampling rates, others on HF have seem the same "won't decode
> strong signals" problems too.
>
> In the current case, with G0NBD, I guess the problem, whatever it is, is
>  at the sending end, as similarly strong signals from others (M0BMU and
> G4JNT) decoded fine here, and elsewhere, yet many people had trouble
> with G0NBD's signal.
>
> I see that Chris G3XVL often reports a +13dB s/n ratio for Jim's signal,
> which shows that strong signals can decode correctly.
>
>
> The question of brevity in passing information (ie "having a QSO") is
> moot - it's not really intended for that purpose. It's point is to allow
> monitoring of the path conditions, using low power "weak signals" - WSPR
> stands for "Weaks Signal Propagation Reporting". If you want a mode for
> conveying information and exchanging reports then there's a whole gamut
> - not least among them good old CW.
>
> WPSR allows the collection, automatically, of data showing the changes
> in path conditions over time, with a centralised online database of the
> results, allowing others to do whatever number crunching they care to on
> the data. For this the mode is perfectly valid, and given low enough
> transmit power from the stations involved it shouldn't cause too many
> problems for other band users. Last night's results showed that, for
> inter-G (even up to Shetland) the ERPs involved were too high. Gary,
> with his 5W TX and 2mW ERP is showing the way it should be done - and
> that wouldn't cause too much QRM for those seeking CW QSOs elsewhere on
> the band.
>
Over the years I have worked W6 and W7 area and VE7 many times on 160m plus 
KL7 on normal CW not to mention KH6 and ZL
    G3KEV


> Using WSPR on 160m recently I discovered that I have a regular opening
> to N6TTO on the west coast of USA, and I'm often the only Eu station to
> receive him. Relying on more traditional modes I'd probably never have
> discovered this. It means that perhaps my location is suitable for 160m,
> and might be worth some investment in time/effort to get on the band.
> Without the research using WSPR I'd have not realised that my location
> was special - although my low noise floor has already proved its worth
> on 500kHz.
>
> Just a few thoughts from here.
>
> Cheers,
>
> John
> GM4SLV
>
>


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