Это подтверждается приведенными ниже наблюдениями "корифеев" топбенда.
Is it just my imagination or have others noticed big 160 meter openings - hours before big K index spikes?
It seems that several times, we have had big openings into Europe and Asia from out here in Arizona and my hopes of having a great opening the next night was ruined by a big geomagnetic storm. Last Saturday morning, the JA-s were quite weak here. Sunday morning, several Asians had good signals.
BD4WN was the loudest I'd ever heard him and JA3YBK was 10 over 9 at sunrise until 15 minutes past sunrise. He was still solid 45 minutes after sunrise. Sunday night, I heard the first EU Russian since getting on TB almost three years ago. I was looking forward to a great post-contest Monday night and bang - the K index jumped up to 4 - just like a few weeks before. I heard no Asian signals this morning and so far no EU on 160 tonight (Monday night).
73 all de Bob N6RW Prescott AZ
However the very best of conditions I have seen is when the K index stays very low at 0 or max 1 for several days. Then the big US openings can happen and I can end up working all states in a week contest. If it times correctly with a contest. Bring it on.
73 Clive GM3POI
I always check 160 on my GMT Christmas Eve - In 2013 I worked 8 EU in about 30 min - from here on city lot in Phoenix, AZ . Just an 80M inv vee at 39 feet !!! So far no repeat. Guess Santa Sleigh not in right place again
I have also seen big openings here in Oregon just prior to a big solar event.
If I recall correctly it was when I worked the A4 which is huge from the Pacific Northwest.
I have also observed enhanced, and sometimes extraordinary, propagation at the onset of disturbed conditions. A recent notable example was the LP QSO with VK6VZ that I reported last month: http://lists.contesting.com/pipermail/t ... 52869.html. At the time of the QSO, the K index was 6.
However, disturbed conditions do not always bring enhanced propagation. There is not a 1:1 correlation in my experience but it's worth checking the band when severe geomagnetic conditions are imminent
73, John W1FV
The "boost before bust" phenomenon has also been noticed by DX listeners of the AM broadcast band.
Here on the US East Coast, some of the more reliable northern European signals are the UK stations on 693, 882, 909, 1089, and 1215 kHz. We used to have the Norway "flamethrower" on 1314 as a great propagation beacon but that station, like many others in northern Europe, has gone dark.
When solar flares occur, radiation travels outward at the speed of light, making the trip in a bit over 8 minutes. Charged particles are also ejected: these may take a day or so to reach Earth's ionosphere.
The effect of that initial arrival of radiation seems to be enhanced higher latitude northern hemisphere propagation.
As the charged particles start coming in and the A/K indices rise, high latitude routes are attenuated. In the early evening here in Massachusetts, for instance on 750 kHz, you would go from good reception of a station in Newfoundland (CBGY, Bonavista Bay) over to a channel dominated by a station in Caracas, Venezuela (YVKS). Northern European signals go away. If anything is coming across the Atlantic at that point it would be African signals such as Mauritania on 783, Canary Islands on 621 etc. Mostly a lot would be heard from Latin America. Brazil, Venezuela, Colombia, and Puerto Rico are quite prominent since many of the more-northerly interferers (US, Canada et al.) are blocked out.
Mark Connelly, WA1ION
South Yarmouth, MA, USA