Propagation News – 8 October 2017

| October 6, 2017

Last week saw sunspot activity remain fairly stable, with the solar flux index hovering in the upper 80s. There were no solar flares and so no associated coronal mass ejections either. On the whole, geomagnetic conditions were a little more settled than they have been of late and other than a K-index of four on Monday the dial sat mostly between one and three.

These more settled conditions, coupled with the expected seasonal uplift in ionospheric propagation, meant there was DX to be had. Maximum usable frequencies climbed to more than 24 MHz at times, although 21MHz was perhaps a little more reliable.

A quick look at the International Beacon Project frequency on 21.150MHz saw the South Africa, Israel and New York beacons audible at times. The Russian and Madeira beacons also made a good showing on both 14.100MHz and 18.110MHz. The five watt ED6YAJ beacon in Majorca on 28.235MHz was even audible for hours on Thursday, with few other signals on the band. Beacons are always useful tools to get a quick snapshot of HF conditions.

Critical frequencies over the UK have struggled to get much above 6.2MHz at times, which means 80 and 60 metres remain the main bands for near vertical incidence skywave or short skip contacts around the UK.

Next week, NOAA predicts the solar flux index will decline further into the low 70s as the current crop of sunspots rotate off the disk. Stormy geomagnetic conditions are predicted for Wednesday the 11th to Sunday, 15 October, thanks to a recurrent coronal hole. If this comes to pass we would expect the best DX to occur in the first half of the week.

VHF and up

The next week or two looks very much like an autumn sequence of unsettled weather, with low pressure dominating the charts throughout this week and next. There may be brief periods when a ridge puts in an appearance in southern Britain, but this is likely to be transient and not a strong tropo signature. Of course, such conditions become a test of all those summer antenna jobs, so this is a good time to check that all the ropes and guys are secure.

The strong jet stream at times over the coming week would have been useful for sporadic E in the summer season, but is of little value at this time of the year.

There are three minor meteor showers this week. The Draconids is today, the Southern Taurids on Tuesday and the Delta Aurigids on Wednesday. All of them have just single-digit zenithal hourly rates, so continue to look before dawn for the best random meteor scatter contacts on the lower VHF bands.

The Moon reaches perigee on Monday and maximum declination on Thursday, so a good week for EME. Look out for OK1VVT, QRV from Morocco on 144MHz as CN2R, and OK1DFC in Ceuta operating from the QTH of EA9LZ, on 70, 23, 3 and 6cm. More details on the HB9Q logger and

Category: GB2RS Propagation News