sabato 27 ottobre 2018

Propagation News – 28 October 2018

We were blessed with quieter geomagnetic conditions this week. And despite the solar flux index only being around 70, a more settled ionosphere meant there was DX to be had. The 6G’s VK9XG DXpedition to Christmas Island off the north-west of Australia has been worked on many bands from the UK, including 160 and 80m. As well as RTTY, SSB and CW, it is also running FT8 as the primary data mode in ‘fox and hound’ configuration, so there is a chance of a contact for lesser-equipped stations too. VP6D on Ducie Island, east of Pitcairn Island, is also active and it too is using FT8 as well as other modes. So generally, HF conditions have been better this week, helped too by the more advantageous autumnal conditions.

Next week NOAA predicts the solar flux index will be pegged at 68. Geomagnetic conditions may be unsettled on Monday, the 29th, due to a small coronal hole, but the rest of the week should be better with a maximum K-index of two.
Make the most of the better conditions as the prediction is that we are in for a geomagnetic disturbance across the weekend of 3 November, and into the beginning of the following week, due to recurrent coronal hole activity on the Sun. This is likely to be due to the return of a coronal hole that pushed the K-index up to five on 7 October, and which has taken around 27 days to rotate back into view.

And don’t forget that this weekend is the SSB leg of the CQ Worldwide contest, when there will be many high-powered and well-equipped stations on the band.

VHF and up:

After some very good tropo for those in the south and west of the UK last week, the weather is changing. British Summer Time has ended and we see a cold northerly airstream flooding down across the country. This is also a signal that the high-pressure system and its tropo of last week are gone, now replaced by windy, showery-type weather. In terms of propagation weather, there could be some useful rain scatter on the microwave bands as heavy showers develop in some coastal regions. Some models do suggest that there may be a hint of high pressure later in the week, but it’s not looking like a very strong contender. Tropo chances could improve though, as the week progresses.

While it will be a quiet week for weather-related propagation, there’s always aircraft scatter on the microwave bands to keep the DX interesting. The digimode JT9F Fast seems to be the best for these bands if fast CW or repetitively chanting call signs and reports on SSB is not your thing.

The Moon reaches maximum declination on Monday and perigee on Wednesday with lowest path losses meaning a good week for EME.

There are no meteor showers this week, so look for the usual enhancement around local dawn for the best meteor scatter contacts as our side of the Earth is rotating into the flux of meteoric particles.