venerdì 12 gennaio 2018

Propagation News – 14 January 2018

January 12, 2018

Last week, we continued to suffer the effects of coronal holes on the Sun, which are very prevalent at this point in the solar cycle. On Wednesday, HF was very lacklustre with little on the bands and 20m closing around 4pm. Having said that, there were pearls to be found. The 6O6O DXpedition to Somalia has been worked by many UK stations on 20 and 15 metres and Japan has been heard on 40 metres.

In midwinter, it can pay to check out 80 metres too. The USA is often romping in on SSB at the top end of the band around sunrise. Even if you have a compromise antenna you may be able to hear the louder stations, such as Mitchell, KH6M in Naples, Florida. Just listen around 3.795MHz for the 80 metre DX nets from 7.00am onwards. Transatlantic signals will start to fade out after sunrise around 8am as the D layer starts to build.

Next week, the solar flux index is predicted to remain around 70, reflecting zero sunspots, but we may get some geomagnetic disturbances due to the ongoing effects of coronal holes. NOAA predicts the K-index may rise to a maximum of four, bringing unsettled conditions this weekend. Unsettled conditions are also predicted for the following weekend of the 20th and 21st, so mid-week may be best for HF. As always, we recommend using tools, such as the International Beacon Network, DX Cluster, or Reverse Beacon Network, to get a real-time snapshot of conditions. Or best of all, get on the bands, tune around and call CQ! Overall, make the most of the low bands—160, 80 and 40 metres—which are at their best this time of year.

VHF and up:

There has been some tropo over the last week, but the conditions are on the turn again as pressure falls and a cold front crosses the country after this weekend. Any remaining tropo will be gone by Monday evening as the cold front arrives and introduces a cold, showery west to north-westerly across the country.

Much of the coming week will be rather windy with showers, so microwave bands rain scatter, satellites and aircraft scatter at VHF and above should be the modes of choice. There’s still plenty to keep DXers happy!

We are now entering the annual ‘low’ in sporadic meteor activity that lasts until the Lyrids shower at the end of April, so you’ll still need to work hard for meteor scatter contacts.

The Moon is at apogee on Monday and minimum declination on Tuesday, so EME opportunities will be short with low moon elevations and path losses at their highest of this month’s lunar cycle.