sabato 28 gennaio 2017

Propagation News – 29 January 2017

Last week saw a flurry of sunspots appear that pushed the solar flux index to 87 on the 22nd. Geomagnetic conditions were unsettled last weekend, but this week has largely seen a respite, with the K-index often being one or even zero. This resulted in good conditions with the maximum useable frequency hitting at least 21MHz over 3,000km at times. There were reports of good openings on many bands, and a higher daytime critical frequency meant that 40 metres often opened up for contacts within the UK around the lunchtime period.

At the time of writing, sunspot group 2629 continues to develop, but according to NOAA the solar flux index will decline to the high 70s.

Unfortunately, next week will be largely unsettled with the K-index predicted to hit four or five from Tuesday, 31 January to Sunday, 5 February. Not surprisingly, this is due to another coronal hole on the sun’s surface.

On the bright side, 80 metres has been showing some good intra-UK openings outside of the mid-day absorption periods. It has also provided some good DX during the night and around the dawn greyline time, when it can open up to North America. These won’t last forever so make the most of them.

VHF and up:

The middle of last week saw the beginning of the end of the high, which gave some modest lift conditions for some. All is changing now that the Atlantic fronts are beginning to move in and it looks like there will be a sequence of fronts and low pressure systems throughout the coming week. This will put paid to any extension of the lift conditions and much of the new week will be uneventful from a tropo perspective.

Look out for rain scatter on the GHz bands though if the weather brings any heavy showers.

Don’t complain that you never get good VHF conditions on a Tuesday evening during the activity contests. You severely reduce your chances of DX if you limit yourself to the same day every week or month. Remember that there are six other days and nights and there are always aircraft scatter contacts to try on 432MHz and upwards to 10GHz.

The winter meteor activity minimum continues, but there are still opportunities for random meteor scatter contacts around dawn. Moon declination goes positive on Wednesday and it’s coming in towards perigee, so moon windows will get longer and losses will fall as the week progresses.
Propagation News - 29 January 2017 - Radio Society of Great Britain - Main Site : Radio Society of Great Britain – Main Site