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From: <jrusgrove@comcast.net>
To: <rsgb_lf_group@blacksheep.org>
References: <COL122-W38C1235D3844DFAD02F983D34A0@phx.gbl><4CD1CD51.2010103@kpnmail.nl><1288819317.4cd1d275cc0bf@imp.netikka.net><000f01cb7ba6$b2802040$8d01a8c0@JAYDELL> <20101103231846.79a9e9da@opc1>
Date: Wed, 3 Nov 2010 20:25:38 -0400
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Subject: Re: LF: WSPR window
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John, Group

Good discussion.

While you might currently get some spots from the US stations in receive mode this number will go 
down as more US stations become active as the season progresses. More WSPR time slots will be 
clobbered by more locals - there's no way around that. Many US stations run 'large' antennas and 
appreciable power compounding the problem. Local (out to a few hundred miles) groundwave signals can 
be well over S9 here and completely lock up WSPR.

Don't believe there is a direct comparison between 40/30/20m operation and LF / MF. Most of the 
stations using WSPR on 40/30/20m, with little to no groundwave, may never even audibly hear another 
WSPR station let alone have to contend with S9 plus mega signals.

There's no reason that US stations can't listen on 502.4 while transmitting on 499.6. This would be 
the best of both worlds as far as logging T/A information. Alternatively, E > W could occupy a 
designated time slot and W>E a different designated time slot to alleviate the interference problem.

It just seems that some sort of a coherent plan would yield better results than an ocassional 'luck 
of the draw' spot because a number of stations happened *not* to be transmitting.

Jay



----- Original Message ----- 
From: "John P-G" <gm4slv@sighthound.demon.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: Wednesday, November 03, 2010 7:18 PM
Subject: Re: LF: WSPR window


> 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
>> >
>> >
>> >
>>
>>
>>
>>
>>
>
>
>
> -- 
> http://gm4slv.blogspot.com/
> http://www.facebook.com/john.pumfordgreen
>