Mode: MM
Venue: Jinsha Base of the Foshan Chancun District Radio and Electronics Society
Team members: BA7NQ, BA7JA, BA7NO, BA7MY, BI7KCD, BI7MPX, BD7IOP, VR2KW, BA7JS, BD7KSF, BA7MAA, BD7OEU, BD7MQ, BD7IXG, etc.
During the competition, other enthusiasts and affiliated associations also came to participate and exchange ideas.
40-meter antenna: CREATE 714X, three-element array with preamp, 18 meters high, DIY two-element, full-size, 10 meters high.
20-meter antenna: CREATE CY203, full-size, three-element, 20 meters high
15-meter antenna: CREATE CL15, five-element full-size, 15 meters high
10-meter antenna: CREATE CL10/CL10/CL10, five-unit full-size, 19 meters / 14.5 meters / 10 meters high
Radio: FLEXRADIO × 4
Amplifiers: ACOM 2000A × 2, ACOM 1200S, 3MN
Competition software: DXLog.net 2.5.44
I strongly recommend DXLog.net. During the competition, a total of six computers were connected and used, which was very stable with no software errors. The UDP broadcast log synchronization worked quickly, and the user experience was excellent. The spectrum display in the SmartSDR operating software for the radio station was also simple and easy to use. After several competitions, I successfully transitioned from Win-test to DXLog.net, and I recommend that you try it as well.
DX Cluster: www.bg4gov.cn
It's also worth noting that their work is stable and they respond quickly.
The solar activity cycle is gradually entering its peak, and everyone is eagerly anticipating this WPX competition. However, human calculations are not as accurate as nature's predictions. On Thursday, a major geomagnetic storm occurred, significantly impacting shortwave communication. I didn't see any signals at all on the frequencies. BA7JA told me that based on the data he collected from his base, the number of FT8 signals was less than 1/10 of normal levels. He suggested that strategies for the competition should focus on communicating with Australia.
On the other hand, weather forecasts indicate that Foshan will experience severe convective weather on Saturday and Sunday, with WPX races often affected by adverse conditions. This is a common occurrence in this region. We were aware of this possibility, and the impact was due to power outages and electrical faults. The power company responded quickly, arriving on site despite the rain to carry out repairs. The entire process took approximately one hour.
On the first day, the competition started at 8:00 AM. The 21 and 28 MHz bands were not as bad as expected; many radio stations could still be contacted. However, the impact of the solar flare was that distant stations had weaker signals, especially the reduction in the number of North American stations, which also affected the number of QSOs. The 14 MHz band was even more challenging, with fewer than 200 QSOs throughout the day. The 7 MHz band was also very difficult, with a white space on 80 meters, but it followed the pattern of increased impact in lower frequency bands.
By 10 PM, 14 MHz finally experienced a "surge," allowing for a good number of QSOs to be maintained until 6 AM the following morning, filling in the QSO gaps from the daytime. The main control station on 14 MHz had two sets of antennas available, one of which was a pair of fixed south-pointing antennas that made a significant contribution to 14 MHz's communication with Australia and Oceania. During the contest, it was possible to switch to the Australian direction at any time, and the YB signal immediately went from being faint to strong, like thunder. Due to the proximity of Zones 7 and Oceania, a pair of eight-element antennas typically performed well, and because the two sets had limited directional capabilities, a single fixed-direction antenna could cover a large area.
Under magnetic pulse conditions, the general propagation pattern is as follows:
* At approximately 21 and 28 MHz, both frequencies can be used. The 28 MHz frequency provides slightly better performance, resulting in a higher QSO (communication) count.
* Around 8 PM, the 28 MHz frequency gradually decreases, while the 21 MHz frequency maintains good communication for an additional 2-3 hours before completely ceasing.
* The 14 MHz frequency starts at approximately 10 PM and continues until around 6 AM the following morning.
This pattern shows a sequence of opening and closing frequencies: 28, 21, and 14 MHz, progressing from high to low over time.
After the first day, we achieved over 2600 QSOs, a success rate of 850+, and a total score exceeding 6 million.
The following day, the propagation pattern was similar to the first day, with 28, 21, and 14 MHz opening sequentially. During the day, it seemed that 21 and 28 MHz were dominant, but at 10 PM, 28 MHz experienced a significant drop, while 21 MHz saw a surge. The difficult daytime performance of 14 MHz was somewhat alleviated in the evening starting at 11 PM. There was a particularly challenging period around 10 PM when propagation was at its worst, with values reaching 12 million, leading to the belief that the competition would end there. However, the operators did not give up. Starting at 11 PM, the situation reversed, and both 14 and 21 MHz experienced a resurgence. The opening of 28 MHz on Monday morning added several new coefficients to the competition in its final stages.
The competition ended with 4800+ QSOs, a coefficient of 1200+, and a score of over 1.5 million.
Overall, the magnetic pulse had a noticeable impact on the number of QSOs achieved, preventing many operators from fully utilizing multiple stations, especially in the lower frequency bands. For example, I didn't hear any contest signals on my 80-meter station, and ultimately gave up. The reduction in North American QSO numbers also resulted in a loss of several prefix coefficients, with a difference of approximately 1300 compared to the expected value.
The antenna configuration for B7P in this instance was inadequate, and the limited preparation time before the competition meant that backup antennas for the 7 MHz and 21 MHz bands were not provided, which negatively impacted communication efficiency during the competition. For future competitions, it is necessary to have a fixed antenna directed towards the South Pacific for each frequency band.
In addition to the 28-meter antenna, which uses a physical controller for antenna steering control, all other antennas were controlled remotely via the network. However, some of the steering interface controls were unstable, affecting the user experience. The plan is to make modifications after the event.
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