Well, although geomagnetic conditions were pretty unstable yesterday (peak Kp~4), the expected CME didn't seem to arrive on schedule. At the moment, NOAA are now expecting, with "diminishing confidence" a storm today, peaking at G3 levels. I suspect it may never occur.
Even so, the conditions were sufficiently rough to totally obliterate any DX overnight. The only stations I heard at all at 14MHz WSPR were 5W from G0CCL - an unusual duplicate spot event occurring only once at 01:06UT, and a single reception of 0.2W from DK9ES at 01:26UT, both stations around the -24dB level. This was, respectively, 26 minutes and 6 minutes before a magnetic field shock was detected at the L1 point at 01:32UT.
The recent, quieter-conditions, near-continuous overnight reception of stations from 8P, 9Z and CE simply vanished at 20:06UT.
My own 1W transmissions were only heard once, at 00:44UT, by 0E9GHV, at -21dB, during a temporary rebound to quieter conditions.
A CME impact with Earth is predicted to occur later today (09/12), continuing into tomorrow.
Peak activity is forecast to reach Kp=7, or a G3 event - by far the most significant such event for a while.
Data shows the early part of the CME arrived at about 06UT this morning.
Even from my latitude of 53 degrees north, good aurora is not so uncommon.
These events afford plenty of opportunity for unusual propagation on all bands, both during and immediately afterwards.
From 12m up, you can experiment with direct reflections off any aurora that you may be within sight of. Unlike many other areas of radio work, auroral propagation is best worked with a 2-element or similarly small beam, such that you don't focus too narrowly on one, rapidly changing area of the event.
To whet your appetite (I mean, you have enough time to build a 6m beam today!), have a listen to this fabulously atmospheric auroral SSB QSO going on in 2015:
Below upper HF, you might discover the beautiful trans-polar flutter or warble that affects signals taking that path over a disturbed geomagnetic field.
Or you might want to see how WSPR transmissions are effected by the disturbance - unexpected local and DX spots, enhancements and band closures are all possibilities, as is the phenomenon of signal spreading on lower HF, which may render many or all WSPR signals non-decodable.
The biggest problem with an event like this is deciding what to concentrate your efforts upon!
Not quite radio, but just have a look at this stunning new image of a sunspot from the Hawaii-based Inouye Solar Telescope, showing detail as fine as 20km across:
The 12m band continues to give generously this week, with daily openings to VK from Europe. The band opens before 08UT here in Wales.
I was happy to make another VK QSO using ~40W this morning with VK3ZH along the short path - although my beam was a good 25 degrees off the direct heading. Brendan is using a 3-ele SteppIR beam, which is really doing a good job for him at 120W, as he was hitting my 3-ele LFA at +13dB at times. Some minutes later, he was down at -18dB. Some minutes later, the band went dead.
Another opening to VK this morning. Terminator correct at time of QSO with VK3MH
Overnight geomagnetic field conditions were intially fairly quiet, with low-level 'ringing' up to about 18UT, whereupon the field became quiet until a minor disturbance occurred from just before 00UT, lasting until about 07UT. The plot below shows the situation at western Greenland (a suitable meridian for a UK/Barbados path):
The signal from 8P9HA (0.1W) at 14MHz WSPR responded nicely in step with field conditions at high latitudes, showing a vanishing of the signal at just after 19UT, and a reapparance at 00:40UT, peaking strongly then at 02:16UT, and finally dying away after 03:16UT as the field began to flutter back to a quieter level.
There is a break of about an hour in reception from 03:18UT until 04:32UT, where a small deviation in the field at more southerly latitudes in Greenland comes into effect, which may be the cause of the loss of signal.
8P9HA 14MHz, 0.1W WSPR received signal at MW1CFN 2020 December 07-08.
Fine, calm weather came to rest over North Wales today, so off we went to the coast with the 'John (Cheap) Loop'. Or maybe it's the 'Cheap John Loop'!
Final test at 14MHz with horizontal polarisation (perpendicular to loop, out to sea).
Vertical polarisation testing with WSPR, 14MHz.
The main aim of the experiment was not to see how the coast enhanced reception (the site had a limited sea horizon to North America, for example), but to look at why the changes in received signal strength with loop height occur. Overall, the loop performed identically (actually +0.25dB better) than the delta loop back home, but with the strong caveat that the NW horizon, from which most US stations are arriving, was not a clear sea one at the coast. Even so, for a tiny loop, that's pretty good!
VK3YE compared signals with a loop being wafted around in height and orientation. He reached conclusions about the loop based on what he could hear - but not on the real reason why the changes in signal strength were taking place. Have a look:
I slowly reached the conclusion that it wasn't height per se that was responsible, but the way in which the antenna couples to the ground with height.
I made a GIF of two analyser screengrabs, which nicely shows the dramatic shift in matched frequency as the antenna is changed in height. Remember, this is an extremely high Q antenna type, so shifts in matching like this massively detune from the desired frequency.
Conclusion? The received signal strength with height will change depending on the height at which you first tune it. If you look and listen again at the VK video carefully, you will see that, contrary to the "not much difference at all" claim, there is actually a big difference with changing position in the vertical plane: it's strongest at about waist/chest height - probably the height it was first tuned, and drops off sharply with any increase or decrease in height from that position.
With VK3YE's loop held horizontally at ground level in the opening sequences, the coupling to ground would of course be very strong, and the tuning, which I'll bet my bottom dollar was done when he was standing up, would be very much further off than in my example above. And in any case, nobody would realistically use a loop flat, almost on the ground.
I'm afraid we will have to wait for another day before I can start answering the question whether the loop, when properly matched at all heights, works better at some height, rather than others. Very short daylight hours also lead to rapid propagation changes at this time of year, so it's actually a tough experiment to gather enough data for.
Interesting to note that, under quiet geomagnetic conditions overnight, the only two stations being heard throughout the night at 14MHz WSPR here were 8P9DH (5W ouput) and 8P9HA (0.1W) - transmitters separated by only a few kilometres.
No propagation model predicts that this situation should occur. Yet it does. The all-sea path seems to be important, because Barbados signals do pop up regularly when few or no other stations do, even in the depths of winter night.
Curiously, and perhaps down to one station using a directional antenna (enquiries ongoing), the received signals are not very different, despite the transmitted power output being 17dB different.
Proppy area SNR coverage prediction for generic QRP settings, 02UT.
Proppy prediction of short path between Barbados and Wales, with generic, low power assumptions.
UPDATE:
Situation the following evening, when the geomagnetic field was completely flat, which also saw the appearance of CE3JSX, reacting to the same influence as the 8P stations in the post-00UT sector:
Vertical being used at CE3JSX for 14MHz WSPR, taken in the past days. Image (C) and by permission CE3JSX.
