I don't often hear Japan, which is amazing because there are so many thousands of active hams there. When I do hear them, it is normally over the polar path and the signal;s are weak and fluttery. (I notice the same with China, Singapore, Taiwan, Thailand, etc).
There are exceptions: I worked Indonesia on 15 meter SSB at 8 AM local, but that was back in early 2002 just after the solar sunspot peak. And I did work Indonesia again on 40 meter CW in 2005, Dec 31st, late in the afternoon. That was pretty amazing and unique, strong signals and a huge pileup. Must have been unique because I was running 100 watts into a Cushcraft vertical. Clearly, that signal was NOT polar. It must have been skew, or more likely long-path because the time was late afternoon for me and there path of darkness for 40 meter prop was long path (40 meter signals don't propagate very well in sunlight, that's another story). Here's a pic of the solar position as it was on Dec 31.
With a strong non-fluttery signal, it did NOT come over the pole. But I have never had that happen again, so it probably was a one-time thing.
Back to today - I heard JA1LZR, Joe in Tokyo, on 17 meters, coming in really strong at 5 PM local time. NO POLAR FLUTTER. Wow, I thought, this is not a common occurrence. And he was a LOT stronger on the off-center-fed dipole than the vertical.
17 meter signals DO propagate better in sunlight. If they propagate (remember the solar conditions are pretty poor). I have tried to work JA on 17 meters before, with very limited success.
What is the position of the sun today?
What did JA1LZR look like today? Strong!
And it was not point-to-point just to me like my VK QSO three weeks ago. JA1LZR worked KP4, W9, W8, and another W4 after me.
What other data points would indicate that this was long path and not over the pole? Take a look at the radiation pattern of the off-center-fed dipole. It has a lobe in the long-path direction (although also in SP direction).
What other facts support the long-path hypothesis, besides strong signal with no polar flutter? Look again at the picture above in the lower left, of the PATH! The long-path signal travels almost along the sun line. This is also known as the grey-line, a special region with enhanced propagation signals.
More proof? Joe was running 800 watts to a 4 element SteppIR yagi. His signal never varied in intensity in the 20 minutes I listened. If he had gone the short path, the signal should have increased in strength as the sunlight over the direct path improved.
About 5:45 PM, his signal was suddenly no longer there. Gone. He had just been in a QSO shortly before then, and other stations were calling him. If the sunlight was increasing over Japan and I still had daylight, how could the path just disappear? It didn't. What disappeared (or changed) was the long path via the gray-line!
Now it could have been a skewed path, not direct long or short but indirect. No way to confirm or refute this, but normally skewed paths are (I believe) point-to-point like what happened with my 5 watt VK4 QSO on the dipole several weeks ago on 20 meters CW. NOONE ELSE HEARD HIM, HE WAS S9 HERE, THEN HE WAS GONE. That was a skew path.
This is not that circumstance.
So, I worked JA on 17 meters this afternoon, first call, on the dipole. He was strong. I am happy. Even the blind squirrel finds a nut occasionally!
73 and good DX