[UK-CONTEST] NFD 2004 10m QSOs Preliminary Thoughts - longish comment

[Steve Reed]

I didn't take part in NFD but 10m propagation in contests is a subject on 
which I have a particular interest, so perhaps I may be permitted to make 
some observations?  Actually I was operating in the UK 6m Group contest 
(which overlaps NFD) from within the M4 corridor and I was monitoring 10m 
beacons as a propagation aid throughout the contest, so I am not making my 
observations completely blind...

Chris is correct in highlighting location as the principal external 
influence on 10m inter-UK scores. An average station has a typical range of 
about 100 km for "local" QSOs.  To be pedantic, these are not ground wave 
beyond a few tens of km but are tropospheric forward scatter - 10m behaving 
in this instance like a poorly performing VHF band.  Open section stations 
on a high, clear site may be able to work 200 km, especially if there are 
enhancements (which on 10m are most likely at dawn and dusk).  Antenna 
cross-polarisation is a killer though.  Clearly you do need to be within 
range of the population centres to maximise station availability and score. 
 South Oxfordshire gets my vote for population/activity centre-of-gravity.

Its rare not to have at least some 10m sporadic E on every day in June: 
there certainly was sporadic E about during the contest but you'd have to 
have been on your toes to make the most of it.  The best spell on Saturday 
at my QTH was around 19z and as late as 2130z I worked 5B4 via double hop 
on 6m - but how many NFD participants are thinking 10m at that time?  On 
Sunday mid-morning I was hearing the EA4DAT 10m beacon loudly for over an 
hour.  Geographic advantages for working sporadic E are not easy to 
characterise.  Over a season, southern UK stations undoubtedly see more 
sporadic E than northern UK stations, but each individual event has its own 
characteristics and on the day any area may be favoured.  When conditions 
are marginal (as last weekend) northern stations might have a slight 
advantage because only long hops are supported - i.e. towards the 2000 km 
range.  This is because if you are in northern Britain more of the 
populated continent falls into this range than if you are in the south. 
 For example, at my (southern) QTH last weekend an arc from 9A through 
southern Italy and 9H to southern EA and CN8 was available on 6m: most of 
my 2000km hop "catchment" lay in the Med, which doesn't provide much in the 
way of QSOs!

There is always some propagation on 10m, though it may not be worth the 
effort required to make a QSO.  If you really *need* to make 10m QSOs then 
try meteor scatter.  Available very day in the early mornings, very 
reliable at 1000 km range, no particular geographic bias.  Needs reasonable 
ERP but, and more to the point, time to make the QSO and someone at the 
other end who knows what's going on.  How very frustrating to hear in the 
bursts someone replying to your call with "sorry, QSB, please call 
later..."  OK, not for NFD perhaps...

I for one would be interested to see more analysis from the NFD logs.  The 
right kind of worm can to open.  Perhaps some information on time of 
contact would be useful?

A final, general comment.  Inferences about propagation from contest 
results may be limited because:

1) activity levels on one band are inter-dependent on the activity levels 
on other bands.  In this case stations are unlikely to spend much time on 
10m when QSO rates are better (or thought to be better) on other bands, 
even with QSO point advantages; and

2) only 1 QSO is allowed with each station per band so if you have worked 
the available stations any subsequent changes in propagation will not be 
reflected in the log. It doesn't sound like this was much of a problem last 
weekend!

Steve G0AEV
.


-----Original Message-----
From:	G3SJJ [SMTP:g3sjj at btinternet.com]
Sent:	Tuesday, June 08, 2004 9:14 PM
To:	uk-contest at contesting.com
Subject:	[UK-CONTEST] NFD 2004 10m QSOs Preliminary Thoughts

Firstly thanks to everyone who has sent me data, 10 groups so far. Sporadic
E was definitely absent!

I'll try and put the data in a more technical format but what really stands
out is that the place to be for inter-UK QSOs is the M4 corridor! I think
there has always been a southern bias for Ground Wave Qs, whilst there has
been a northern bias for Es, but I suspect there is also something else
here.

A couple of stations have mentioned an overall lack of /Ps from the UK. Ten
years ago there was over 80 groups taking part, so the chance of you 
finding
someone close to you was reasonable, now it is half that.

A quick check says that probably 40 to 50% of the UK /Ps (and also casual
activity) are in the M4 catchment area and the rest, i.e. another 20 groups
are spread around the UK. So if you are away from this centre of activity
you won't find much to work in the way of UK stations.

Hope I haven't opened a can of worms here, it wasn't intended. The results
were probably predictable but I didn't anticipate it being so obvious.
Chris G3SJJ











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