40m isn’t really HF - it’s the upper end of LF which is generally considered to be <10MHz. LF is not much affected by flares and CMEs but is subject to D-region attenuation during daylight hours which limits range. HF (>10MHz) is not affected by the D-region but is susceptible to disturbances in the much higher E and F layers from both flares and CMEs.
HF is slowly recovering. I just had a CW QSO with the Maldives (8Q7EL) on 15m but signals are still a bit weak and watery. Kp and Ap are finally dropping to more sensible values. This has been a pretty major event but not exceptional - we typically get one or two per solar cycle, often just after the peak as in this case.
I regularly enter the RSGB FT4 contest and Monday night’s was interesting …
It started just as the CME hit, and the FoF2 was already below 3.5 MHz - 80m yielded contacts into Central and Eastern Europe but 40M was near dead.
About an hour later it seems the auroural effects kicked in on 40M and UK stations were appearing even though the FoF2 was now down at 2.5 MHz or so. However there was some typical wobble on the signals which made decoding the signals a bit tricky at times. So 40M does definitely get some auroural effects. Some of the UK stations were coming through strongly (eg S Wales to Yorkshire at S9+)
My summit yesterday was certainly a tough one. Nothing on 40m, 20m was almost dead (save Warren @ZL2AJ and I heard Gerard @VK2IO even if he couldn’t hear me), 17m and 15m were basically one QSO each and I got lucky packing up with a call on 439 FM simplex yielding a 14km contact that I convinced to call on SSB as well for challenge points. All up, 6 contacts, two of them 14km away.
It’s always surprising to me how many people will come back to a CQ call on the simplex frequencies. I even qualified Mount Loch up in the Vic Alps on 2m FM once (although it helped having a family of hams on hiking on the far side of Feathertop )
While it made my activation this time by getting me challenge points, I’ve had responses all through Western Victoria at different stages of my SOTA life on simplex, so don’t write it off entirely. My favourite response to a CQ once was “I have a bunch of radios scanning, but I don’t know which radio your voice is coming out of so I’m trying them all. Is this it?”
To allow for this scenario, and I have heard it a few times on 2 m & 70 cm, I announce the frequency I am calling on so those with multiple radios, or a single radio that is scanning multiple frequencies, know where to find me.
Yesterday around mid day I did the same at Mt Stromlo, drumming up business on the Mt Ginini 2m FM repeater, seeking QSOs on 144.200 SSB. I certainly wasn’t holding my breath with huge expectations but it worked!!
Three local 2m SSB QSOs to complete four contacts.
It’s always surprising to me how many people will come back to a CQ call on the simplex frequencies. I even qualified Mount Loch up in the Vic Alps on 2m FM once (although it helped having a family of hams on hiking on the far side of Feathertop )
While it made my activation this time by getting me challenge points, I’ve had responses all through Western Victoria at different stages of my SOTA life on simplex, so don’t write it off entirely. My favourite response to a CQ once was “I have a bunch of radios scanning, but I don’t know which radio your voice is coming out of so I’m trying them all. Is this it?”
Out here in west of the Blue Mountains there are not many whom use 2 metres nowadays. Years ago lugged a h/held and a J Pole about but rarely if ever got a response. Seems mobile phones and more recently the new geek thing Meshtastic seek to be the things that attract peoples attention.
If you’re wondering why HF conditions are weird this morning, our wonderful sun unleashed an X8.1 flare just before midnight on 1st February. Now that is a big flare! It’ll take a while for the ionosphere to settle down after that and there is the possibility that at least some of the associated CME was earth-directed, in which case we might get some auroral activity in the next few days.
I need to check back but I think this might be the biggest flare of this solar cycle. It’s not unusual for major flares on the trailing side of a solar maximum and it’s quite possible that sunspot 4366 will unleash another before it’s done.
According to spaceweatherlive.com last night’s flare was actually an X8.3 and it comes in at number 3 in the list of most powerful flares in cycle 25.
Interesting to note that we haven’t yet had a Ten-flare (>10) during this cycle whereas in cycle 24, widely regarded as a weak solar maximum, there were two of them. Solar cycle 23, meanwhile managed 10 Ten-flares, one of which was a massive X40+. So by comparison last night’s event was just a warm up act. There’s time yet…
The X8 flare is only part of the story, apparently it was the third X flare and there had been no less than 17 M flares yesterday, so 4366 is an extremely active group. It wouldn’t be a surprise if any CME sweeps up CMEs from the preceding fusillade of strong flares to give a major impact when it arrives - if it arrives, currently I don’t know the CME status. Stay tuned!
Indeed, a veritable swarm of flares and another X1.8 at 08:00Z today so we’re not done yet. Very likely that one or more of the flares will have launched an earth-directed CME. Fascinating thing our sun!
I might just hike (bareback = no radio) for the rest of my trip… or actually, perhaps it’s an excuse to be a tourist for a day (you know, a massive lunch + photos of fountains).
There was something big in October, but it was on the far side of the Sun and I don’t think there were any estimates of the flare intensity: Spaceweather.com Time Machine
I thought there was another huge one that erupted from a spot just as it went around the back of the Sun but can’t find any details.
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