Propagation News – 14 November 2021

This last week was a little more settled than the previous one. The solar flux index remained in the high 80s and geomagnetic conditions were mostly quiet, with a maximum Kp index of three. That isn’t to say that the Sun has been inactive – far from it. A long-duration M2.0 solar flare took place on the 9th of November around region 2891, which is now located behind the northwest limb. Its associated CME was luckily not Earth directed, so it looks like we escaped that one. As a result of the settled conditions maximum usable frequencies have remained quite high. On Thursday lunchtime they were topping out at just over 28MHz over a 3,000km path.

Manubhai, VU2XO in India has been logged on 10m SSB on a few occasions and Stuart VK8NSB has also found his way into many logbooks according to the 10m UK Net group on Facebook.

The 10m Australian beacon VK8VF/B in Darwin has also been logged in Southern Ireland on 28.268MHz. According to the Propagation Studies Committee’s beacon listing on RSGB.org the beacon runs only 25W.

Next week, NOAA predicts more of the same, with the solar flux index rising from around 80 to perhaps around 90 as the week progresses. Geomagnetic conditions are currently predicted to be unsettled around the 15th, when the Kp index could rise to four. But at this point in the cycle it is hard to be precise as CMEs can disrupt the ionosphere approximately two days after a solar flare and CME event, and they are very hard to predict with any accuracy. The best advice is to keep an eye on solarham.com for news of solar events.

And now the VHF and up propagation news.

High pressure will build in from Scandinavia as we move into early next week. This high should bring some Tropo opportunities, but suffer a brief knock back midweek as a new low pushes a weakening front south. After this, a new high will build, but this time from the Azores High with a moister surface air flow and a better prospect for Tropo. The Tropo prospects will favour southern UK regions, whereas the north will remain closer to low pressure and be less likely to generate Tropo. Rain showers may again provide some rain scatter on the GHz bands.

The Leonids meteor shower peaks this week, so obviously a good chance to test out those meteor scatter techniques using digimodes MSK144 and FSK441 if you’ve not tried them before. SSB and fast CW on the lower VHF bands will also be possible for well-equipped stations using the right techniques.

For EME enthusiasts, Moon declination goes positive again on Monday, but path losses are rising as we head for apogee a week today, the 21st. The Moon will be at 34 degrees elevation this evening, Sunday, at its zenith, getting higher as the week progresses.

Category: GB2RS Propagation News