domenica 29 luglio 2018

Propagation News – 29 July 2018

The solar flux index hit 66 on Thursday 26th, which is probably the lowest it will go this sunspot minimum. At the time of writing the visible solar disk has been devoid of sunspots since 27 June, apart from the tiniest fleck that sent the sunspot number to 11 for one day on 12 July. We can probably expect more of the same through 2018 as we make our way through this low part of the current solar cycle.
Geomagnetic conditions were a little unsettled this week due to coronal hole activity, with the K-index hitting four at times. Next week NOAA has the solar flux index pegged at 68 with reasonably-settled geomagnetic conditions.

This weekend is the RSGB Islands on the Air Contest. For those of you who read GB2RS online or catch it on Saturday, expect 40m and 20m to be the money bands, with 7MHz coming into its own after dark. Fifteen metres and 10 metres may struggle to open, other than through sporadic E openings, which are now becoming less prevalent as we move towards August.

Started in 1993, IOTA is now a major international event, attracting thousands of participants from all over the world. Radio amateurs will be travelling to islands around the globe, and putting them on the air, so it is an ideal opportunity to make some contacts.

VHF and up:

The weather is breaking with some heavy thundery showers in attendance this weekend, so there’s the prospect of some rain scatter for the microwave bands. This will only be temporary as fine weather returns from Tuesday. That also means that although we are having a pause from the almost daily tropo weather due to the recent high pressure, it will return from mid-week to give the prospect of some VHF DX paths across the North Sea to the Baltic and Scandinavia, or to the south across Biscay to Spain and western France. Sea paths are often the best under these summer tropo conditions.

The sporadic E conditions have been a bit variable recently, but don’t worry about the change of month, as sporadic E can go right through to early September in a good year. However, we do really need a more changeable pattern of weather to bring us the useful jet streams, which can be good for sporadic E. There are some jet streams about, so you maximise the potential for openings by listening for the beacons and looking at the clusters. The peak times are typically late morning and late afternoon and early evening.

It is only two weeks to go until the Perseids meteor shower, the biggest of the year, so check out your equipment and be ready for some—literal—fireworks on the 12th.

The moon is past apogee again and declination goes positive on Thursday so EME conditions will pick up as the week progresses