Propagation News – 9 August 2015

| August 7, 2015

Further complaints about poor HF conditions were heard this week as the summer doldrums continued, not helped by a less than brilliant solar flux index of about 105. Having said that, the sun is showing more activity with a sprinkling of spots. Geomagnetic conditions were on the whole settled this week, at least until Thursday when the Kp index hit four thanks to a high-speed solar wind stream. A visible aurora warning was issued when the plasma hit the earth after being thrown out from a recurring coronal hole on the sun. A coronal hole is an area where the solar magnetic field reaches out into space so the hot gas can escape.

A look at the Chilton Ionosonde data for noon on Thursday showed that the F2 layer could support communication at up to about 23MHz around noon, but this isn’t typical. The previous day it was around 18MHz. We would therefore recommend trying to use 18 or 21MHz during the day to minimise D layer absorption and maximise your DX potential. After dark move down to 14MHz or 18MHz, which have both brought a few surprises in terms of DX recently. Unfortunately we are still some way away from better autumnal HF conditions.

VHF and up propagation news

This week, meteor scatter operators can look forward to the Perseids, the longest meteor shower of the year. It peaks around the 12th, but there will be plenty of activity on meteor scatter either side of the peak. This is the time to try meteor scatter if you’ve never done it before. Using FSK441 on two and four metres and JT6M on six metres with 50 watts and a small Yagi should give you contacts. At the peak, even SSB contacts are possible.

An area of high pressure just north of the Azores, with a ridge extending along the English Channel this week, will mean some slightly enhanced tropo conditions are possible at times. In particular, there will be some good prospects for ducting along the west coast of France and Spain and down towards the Canaries and Azores. By Wednesday there are prospects for tropo paths across the North Sea.

August means we are drawing towards the close of the sporadic-E season, but note there is still potential for the occasional opening through to the end of the month and in to September. These may be harder to find and relatively fleeting, but it is worth monitoring the beacons nonetheless.

Category: GB2RS Propagation News