Propagation News – 11 February 2018

| February 9, 2018

Sunspot region 2699 provided us with a small increase in solar activity last week. It also produced a number of minor C and M-class flares as the solar flux index rose to around 77. More significantly, quieter geomagnetic conditions, thanks to a lack of coronal holes, meant the K-index remained fairly low and the bands were quite settled. This brought band openings up to 21MHz at times, with the FOC Marathon last weekend giving an ideal opportunity to see just how far CW signals can travel. North American stations from as far afield as California, Oregon, Washington State and British Columbia were audible in the UK. Roger, G3LDI says he had 855 QSOs with 102 DXCC entities on all bands up to and including 10 metres.

Next week, the solar flux index is predicted to remain around 70. Geomagnetic conditions should remain settled until around Friday, the 16th, when the K-index could rise to a maximum of four or five due to incoming material from solar coronal hole activity.

As we are now in February it is worth looking at some propagation predictions. For the path from the UK to New York, tells us that we can expect a maximum usable frequency of about 18.9MHz around 1400UTC with a maximum 10 percent chance of success using 100W to a dipole and SSB on 17 metres.

If you use CW your chance of success increases to 40 percent, and you get a similar or slightly better probability if using one of the newer digital modes such as FT8, which can copy signals down below the noise level.

VHF and up

It’s looking like the changeable period of weather is locked in for another week, with a series of fronts crossing the country and low pressure north of Scotland for much of the time. This will make it rather breezy at times, especially in the north.

For VHF/UHF propagation, the absence of high pressure rules out tropospheric openings, while on the microwave bands, rain scatter from heavy showers is probably going to be rather random and infrequent, as the seas gradually cool down and are less able to generate the heavy showers.

There is always the chance of an occasional aurora to lift spirits for a very exotic mode of operation and, with some strong jet stream activity, it’s not totally out of question that some sporadic E may develop, although such things are very rare at this time of the year. Stick to random meteor scatter QSOs in the early morning for your regular dose of VHF DX.

The Moon is at minimum declination and apogee today, so we have maximum EME path losses and low peak Moon elevations of less than 20 degrees in the UK.

Category: GB2RS Propagation News