Report on VHF National Field Day 2009
This year the field day weekend was held on the 4/5 July 2009. South Bristol ARC operated as G4WAW/P from it's usual location on Dundry Hill. Operation was primarily by: Gary (M0RCE), Andy (G7KNA) and Tom (M3TWJ) although other club members and friends of club members were also present.
The site was well populated this year, with SBARC, NBARC and Matt operating different stations from the site.
This year, with many thanks to Ken (G4XCB), we were able to erect at 30' mast to mount the clubs 14 element 2m beam. Other equipment supplied by Ken includes a 5kW diesel generator which not only supplied power to our station, but also to Matts 6m station, the NBARC 70cm operation and the caravans being used for over night accommodation.
Other equipment in the SBARC station was supplied by Gary (M0RCE) and comprised a Yaesu 800 rotator, 30Amp power supply and Icom IC-901X 2m/70cm/23cm multimode rig with matching masthead preamp. The station was set up in the back of Garys van.
Honourable mentions should go to Fred (G7LPP) who brought a van load of equipment in case of disasters and supplied the refreshments for the weekend.
Thanks to Kens sterling efforts in developing a simple, fool proof method of erecting the mast and antenna we found ourselves in the rather novel position of being ready to operate with 3 or more hours to spare. This time was usefully used to visit the local chip shop and consume a can or two of beer.
14:00 UTC saw us on air, with the first contact being made with 2E0DBD/P after only 2.5 minutes. This was a local station worth only 18 points, but we quickly got one of several openings into the continent and worked French and Dutch stations. Propagation to the north was also good and some distant Scottish stations added to our early points haul.
The table shows that the bulk of the stations worked came in the first 4 hours of operation, in fact almost two thirds of contacts had been made by 20:00 UTC. There were brief bursts of activity coinciding with the start of the contest, around 18:00 UTC as new casual stations came on air for a couple of hours, presumably having completed whatever tasks had been allocated for the day.
Table 1 – Stations Worked by Hour
|Hour Starting (UTC)||Stations Worked||Percentage of Total||Cumulative Percentage|
Given the relatively flat state of the band in the late evening we elected to close down for the mandatory 8 hour break just before 22:00 UTC. This meant that we were able to start again on Sunday at 06:00 UTC. This gave us a slight advantage as many other south east stations were not yet on air but with the continent one hour further ahead we were able to bag a few continental stations before the UK stations came on air.
Again around 09:00 UTC a number of new casual stations came on air, presumably with little else to occupy their Sunday mornings. However it soon dwindled back to the stalwart stations, most of which we had worked on the Saturday.
The QSO rate throughout the contest was 143 contacts in 14 hours (actually more like 13.5 hours) which gives just 10.2 QSO/hour or about one every 6 minutes. However as can be seen from the table above the maximum rate was 27 QSO/hour and the minimum (ignoring the shut down period) only 2 QSO per hour.
Propagation was reasonable to good in all directions except west. No particular reason for this but there seemed to be a limited number of GW, MW, 2W, GI, MI, 2I and EI stations worked. There was also a noticeable increase in the noise floor between a bearing of 260 degrees through to about 300 degrees. The cause of this remains unknown.
Table 2 – Breakdown of Prefixes
|Prefix||Number Worked||Percentage of Total|
|2E, G, M||99||69%|
|2W, GW, MW||12||8%|
As can be seen from table 2 above some 14% of all the stations worked were non UK stations.
The total score, subject to adjudication and normalising was 32,852, which corresponds to an average of 230points per QSO. How the score came about throughout the operating period is shown in Table 3 below:
Table 3 – Points Scored by Hour
|Hour Starting (UTC)||Stations Worked||Points Scored||Average Points Per QSO||Deviation from Average|
In terms of the highest number of points scored, clearly 17:00 – 18:00 UTC was the best hour. This time period included our best and fourth best DX of the contest, EA7TL at 1669km and EC4CLR at 1189km. However the rest of the stations in this period were of a much lower quality.
By contrast, although 06:00 – 07:00 only accounted for 6 QSOs (4%) and 3212 points (10%) the quality of the stations worked at this time led to an average of 535 points per QSO, some 133% above the average for the weekend. The stations comprised a GM, ON, DR and DF station with each one being between 570 – 840 points.
How Did We Perform
It is difficult to draw any firm conclusions about our performance. Certainly the serial numbers being given to us by our QSO partners indicated that whilst some stations were clearly well ahead they were in a minority, and similar numbers of contacts were being made by many of the stations we worked.
Previous scores are also difficult to compare, mainly because of the normalising process that the adjudicators apply, and the differences in propagation year to year.
Following the ajudication process, we placed 17 out of 29 with a normalised score of 28,768 from a confirmed 126 QSOs. Usefully the EA7TL best DX that we thought we had was confirmed, but clearly we lost some points as a result of poor logging either by us or by the other end of the QSO. We thought we had 143 QSOs but only 126 were confirmed, a loss of 17 or 11%.
Never the less the confirmed QSOs is one of the best we have had in recent years, and our points scored is similarly improved from recent years. Even our best DX is the best we have had in recent years.
Although our positional showing is not as good as recent years it must be remembered that we are operating in a different class this year, and overall performance should be considered an improvement on previous years.
An cursory analysis of the points scored by the other operatives in the Restricted Class shows some trends that might prove meaningful:
- 11 of the 16 stations (69%) placed above us were operating from grid squares to the east of us, they possibly had better conditions east into Europe
- 5 of the 12 stations (42%) placed below us were operating from grid squares to the east of us, supporting the above supposition
- In addition to ourselves there were 2 other stations operating from IO81 grid squares. The first of these was G2BQY who managed a confirmed 167 QSOs scoring 33703 points with best DX of 1652km to CT1HZE. The second of these was G4WSM who managed a confirmed 38 QSOs scoring 9589 points with best DX of 1489km to CT1DIZ
- EA7TL was the best DX station for three operations in addition to ourselves
- The average number of QSOs for the class was 128.07, only fractionally more than we had confirmed
- The average points score for the class was 32,426, our score of 28,768 was about 11% below the average
- 18 operations scored a better best DX distance than we did, although the average of 1704km was only 2% higher than we achieved
- Only 3 of the stations scoring more than us claimed to be running less than 100W
- 6 of the stations above us had more elements on their Yagi, although as gain figures are not quoted and antenna height is not quoted these variables are difficult to take into account
The points difference between us and the station immediately above us was 3343. Our average points per QSO based on the confirmed QSOs and the normalised score was 228. On this basis, i.e. assuming that the 17 badly logged QSOs followed this average trend then the 17 badly logged QSOs could have provided an additional 3881 points; sufficient to improve our position by one place. However, as the incorrect details could have been at the other end of the disallowed QSOs it is unlikely that improving our accuracy would have improved our placing although it would have improved our overall score.