Date: Wed, 3 Nov 2010 23:18:46 +0000
From: John P-G <gm4slv@sighthound.demon.co.uk>
To: rsgb_lf_group@blacksheep.org
Message-ID: <20101103231846.79a9e9da@opc1>
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Organization: The Gammy Bird
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Subject: Re: LF: WSPR window
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Jay, LF,


Now I'm confused!

The bulk of the active USA WSPR stations are down at 499.6 "dial",
with RF carriers just inside the UK allocation at 501.1

One or two US stations occasionally might choose to listen up at 502.4
"dial" - the supposed UK/Eu WSPR frequency, but it can't be relied upon
that a "RX only" USA station will take the trouble to tune there.

WSPR is designed to allow very many stations to co-exist in a given
200Hz window, with greatly varying signal strengths (you only have to
look at the density of active stations on 30 & 40m). 

I see no problem in the Eu/UK stations occupying the same region as the
USA stations. At least then we all know, from observing the reported
spots between the US stations on 499.6, that there are people active
"across trhe pond", both in transmit and receive. 

If we use the same frequencies it allows stations in Europe to observe
paths, in both directions, over the pond, by receiving US stations and
by being received by US stations.

I don't agree that weak Eu stations will only be received if they stay
away from the 200Hz region used by the US stations, up in our own
little ghetto. 

I have consitently received spots from WD2XSH/17 at SNR of -26dB or
less, while also receiving PA0A at SNR +10dB or more.

I got several spots myself last night on "499.6 dial" from the USA and
can't imagine that I was particularly hampered by the fact that there
may have been other US stations active in the same 200Hz section.

The point of WSPR is that everyone (yes, everyone) is within a known
200Hz slot, and transmits randomly, to reduce clashing with the real
"big guns" too often. 

As long as people aren't setting very high TX ratios - nothing more
than say 30% - it should work as designed.

The WSPR receive system has very narrow bandwidth and can discriminate
between signals within a few Hz of each other. As long as the "strong
local" QRM isn't continuous - say someone close-by, who causes
extreme AGC gain reduction & has set a 100% TX ratio - then there
should be no problem for us all to occupy the same region of
"WSPR-Space". 

To re-emphasise the point - the density of signals on MF is miniscule
compared to the popular bands for WSPR activity, 40/30/20m

I'd rather take my chances at 499.6 where lots of USA stations are
listening  and transmitting, than hope one or two rogue ones are going
to tune away from the local wateringhole. This way I can test my TX
capability and my RX capability (and hopefully provide some DX
reception spots for US stations).

WSPR is deigned for this purpose. 

I vote for one WSPR zone. 

John
GM4SLV


On Wed, 3 Nov 2010 18:30:19 -0400
<jrusgrove@comcast.net> wrote:

> This is nuts!
> 
> We finally move the US WSPR stations out of the EU WSPR 502.4 window
> down to a new US WSPR 499.6 window so that those that want to monitor
> can have a clear shot at the EU stations. Then the EU stations move
> down to the US WSPR 499.6 window!
> 
> If EU stations are looking for US spots they would be better off back
> in the 502.4 window. Receiving stations in the US are less  able to
> decode EU stations if they are mixed in with strong local US
> stations. Some of the US stations are so strong that when they're
> occupying a WSPR time slot the receiver/decoder is overloaded and no
> weak DX spots are possible. With several strong US stations on the
> air the problem gets even worse - more time slots are clobbered by
> the locals.
> 
> Here's an example from the other night:
> 
> 2010-10-31 00:26  G3XIZ  0.503819  -30  0  IO92ub  +27  0.501
> WE2XGR/2  FN31is  5420  3368
> 
> This was a one shot reception for that night from G3XIZ at signal
> strength -30. Had G3XIZ been transmitting in the US WSPR window and
> several US stations were active it is highly unlikely that this
> reception would have occured.
> 
> The same goes for T/A QRSS. When EU stations transmit in the US QRSS
> T/A window and US stations are active it's just not possible to see
> EU stations as the local strong signals capture the receiver/decoder.
> 
> Obviously stations are free to do what they like ... but trying to
> capture weak DX spots or QRSS screens is going to be far less
> productive if the receiving station is constantly getting clobbered
> by locals.
> 
> Jay W1VD  WD2XNS  WE2XGR/2
> 
> 
> 
> 
> ----- Original Message ----- 
> From: "Paul-Henrik" <phl@netikka.fi>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Wednesday, November 03, 2010 5:21 PM
> Subject: Re: LF: 501150
> 
> 
> Hello Lubos & Jan!
> 
> Yes, they are legit amateur stations in WSPR mode looking for
> stateside spots, at the moment I receive EI0CF and GM4SLV there.
> 
> To receive them, change the default WSPR 600m settings to these:
> 
> Dial: 0.499600
> TX: 0.501100
> 
> And tune the receiver to 499.60kHz USB
> 
> I can clearly see the wideband noise here but WSPR reception is still
> good.
> 
> BR
> 
> Paul-Henrik
> 
> 
> Quoting pa3abk <pa3abk@kpnmail.nl>:
> 
> > It's WSPR. Assume "they" shift to the lower end in order to catch up
> > with US stations.
> > Broadbandnoise is rather high at the mom.
> > Jan/pa3abk
> >
> > Op 3-11-2010 21:43, Lubos OK2BVG schreef:
> > > They are three stations in data mode in QSO. Frequeny 501.150kHz.
> > > Not hams, I think.
> > >
> > > Lubos, OK2BVG
> >
> >
> >
> 
> 
> 
> 
> 



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