sabato 15 dicembre 2018

Propagation News – 16 December 2018

As we are approaching Christmas we have a festive twist to the HF propagation report this week.

Firstly though, this week saw a lack of sunspots with the solar flux index around 70. Geomagnetic conditions were better than they have been though due to lack of coronal holes, with the K-index being two, one or zero as the week progressed. Next week NOAA says the solar flux index will probably be around 68 again, with quite settled geomagnetic conditions and a maximum K-index of two, or perhaps three.

If you fancy something a little different, Santa Claus and his ham radio elves are on from Romania again in 2018 for the third consecutive year. The YP-XMAS call signs are a tradition and the Romanian RadioClub Association, ARR, says it aims to give moments of joy to the radio community around the winter holidays. The Santa Claus story via radio waves was started by Finnish radio amateurs, beginning with OH9SCL in 1986 and, later, the OF9X team. It has been taken over in recent years by different colleagues from several European countries. In 2018, Romania is preparing for the largest team with activators in all the districts of YO. Google YP-XMAS for details, but all you have to do is contact at least three different YP-XMAS call signs and they will be able to issue an electronic award directly from Santa Claus. HF propagation to Romania is probably best on 20 metres during the day, but falls back at night. 40 metres, or more likely 80 metres will be the favourite bands for contacts after dark.

VHF and up:

It’s a low pressure theme from one of the longer-range models, with an area of low pressure right over the country by the second half of next week. A second model is slightly more cautious in bringing the next low in after mid-week, but nonetheless doesn’t really leave room for any high pressure of significance. This all means that the weather influence is very limited during this coming week. No real signs of tropo, but possibly a little microwave bands rain scatter, although it’s not a very strong hint.

This mid-winter period can produce some out of season sporadic E, although it will be limited and fleeting. The best way forward is to monitor the clusters for signs of 10m activity, showing as short-skip signals from Europe.

The Geminids meteor shower is over now so while we wait for the next major one, the Quadrantids in January, it’s back to early morning sporadic meteors for our meteor scatter DX on the low VHF bands.

The Moon’s declination goes positive this Sunday and its orbit is bringing it closer all this week. Moon windows for EME will lengthen and losses decrease as the week progresses, so get active in next weekend’s 3.4GHz activity session.