venerdì 29 novembre 2019

Propagation News – 1 December 2019

Last week’s CQ Worldwide CW event proved that a contest can really generate activity on the HF bands, despite poor propagation. Despite lukewarm predictions during this period near sunspot minimum, there was plenty of DX to be had, despite a solar flux index of only around 70, and zero sunspots. HF bands as high as 15 metres were open, with the occasional station calling CQ on 10 metres as well. Contesters report that 40m and 20m provided a lot of fun with 7MHz providing night-time openings to the US for many. Tom, GM4FDM also reports working 47 countries on 80m during CQ Worldwide, including V47T, which was St Kitts and Nevis and A44A, Oman.

Next week, as we enter December, NOAA has the solar flux index at 69 all week with a Kp index of two. This represents the fact that the Sun’s surface is clear of major coronal holes at this time.

December is really a month for the low bands, with amateurs’ attention often switching to 80m and even Top Band. 160m is always a tough band to work, mainly due to the large amounts of space needed to install efficient antennas. But this month is probably the best for working transatlantic Top Band contacts in the early hours. 80m may also bring some surprises, with regular contacts into the USA being possible, especially around sunrise. Why not check out the DX nets that occur on or around 3.795 MHz?



VHF and up:
It looks like high pressure is coming back, at least for a while in the first part of the coming week, so it’s time to get ready for some tropo activity on the VHF and UHF bands with those multimode rigs. The present unsettled weather will lead into a new high developing to the north-west of Britain, which will then begin to drift south across western Britain, before being pushed aside into the Atlantic towards Biscay around mid-week.

The developing temperature inversion should provide multiple paths across the UK by early next week, especially over western and southern areas. This is great timing for 144MHz contests on Tuesday, 3 December.

Unfortunately, this is not going to last, as the high drifts away midweek. This will allow a new, stronger flow across the north of Britain as lows move south-east down the North Sea. There will be cold north-westerly winds and some possible rain scatter options over the North Sea by the end of the week.

Moon declination is rising again this week but doesn’t go positive until Friday. This means the peak Moon elevation will also increase as the week progresses. With apogee on Thursday, path losses will be at their highest, but 144MHz sky temperature is low all week.

There are two small meteor showers to look out for this week—the Phoenecids on Monday and the Puppid-Velids next Saturday. (rsgb.org)