Wednesday, July 14, 2021
15,000km+ opening on 50 MHz between SE Australia and Europe - 14th July 2021
Wednesday, July 7, 2021
18,000km opening on 50 MHz between Europe and Australia - 7th July 2021
VK3OT-@ 50314.0 UR0MC 06:13 07 Jul CQ VK FT8 Ukraine
VK3OT-@ 50313.0 UT7QF 06:11 07 Jul TNX QSO 73 Ukraine
S57RR-@ 50323.5 VK3ZL 06:47 07 Jul FT8 -19dB JN65um<>QF22 TU! Australia
OH7KM 50313.0 VK2OO 05:57 07 Jul cq -20 Australia
S57RR-@ 50315.3 VK2EFM 05:20 07 Jul FT8 -14dB JN65um<>QF56 CQ Australia
Tuesday, June 1, 2021
Another 50 MHz opening between Australia & Europe - Mon 31st May 2021
Following on from the weak opening on the 29th of May, there was another 50 MHz opening between Europe and Australia on Monday the 31st of May 2021.
The above map from the PSK Reporter website shows the almost 15,000km path that was open for VK4MA on the east coast of Australia.
LY2BAW 6m FT8 14683 km 07:46:59
VK4ABW YL2CZ 6m FT8 12300 km 09:11:59
VK4ABW OG3G 6m FT8 12228 km 08:43:59
VK4ABW OH1MN 6m FT8 12199 km 08:44:29
VK4ABW OG2A 6m FT8 12147 km 08:43:59
VK4ABW LY2BAW 6m FT8 12144 km 08:46:57
VK4ABW OH7KM 6m FT8 12113 km 08:22:30
VK4ABW YL2II 6m FT8 12104 km 09:12:59
VK4ABW OH3SR 6m FT8 12091 km 08:22:26
VK4ABW YL2CP 6m FT8 12090 km 09:11:59
OH3JR VK4ABW 6m FT8 12081 km 08:36:44
VK4ABW ES5PC 6m FT8 11999 km 08:44:59
***
UR0MC VK3OT 6m FT8 13989 km 06:02:11
***
The longest path seems to have been between VK3ZL and SP4K in Poland at 15,459kms
UR0MC VK3ZL 6m FT8 14163 km 06:41:44
***
Propagation Mode: We're back to the same question again... How do 50 MHz signals from Europe reach Australia near the bottom of the sunspot cycle?
The easy 'go to' answer was that it was multi-hop Sporadic-E, case closed.
The problem I'm starting to have with this is down to probabilities.
Take SP4K in Poland. What are the chances of one hop Sp-E in the direction of Australia capable of supporting a 50 MHz signal? It's late May, it's the Summer Sp-E season so it's pretty high.
Two hops?... What is the probability of getting two Sp-E regions spaced at just the right distance to allow a double hop at 50MHz? The probability is obviously lower.
Follow that same logic and apply it to 3 hops, 4 hops and so on. By the time we get to 15,459kms, we're probably looking at 8 hops.
What is the probability of getting eight Sporadic-E clouds capable of supporting 50 MHz spaced at just the right distance from each other... all the way from Europe to Australia?
And if that probability wasn't low enough, what then is the probability of 8 hop Sp-E on 50 MHz from Europe to Australia on two out of three days?
I think the probability is now so low that there must be some other answer. Perhaps TEP (Trans-Equatorial Propagation) from Australia to China accounts for a large part of it? Some other propagation mode?
I'm not sure the simple 'It must be multi-hop Sporadic-E' adds up anymore.
Thursday, July 25, 2019
Unusual 50 MHz opening from Australia to Europe - Wed 24th July 2019
On Wednesday the 24th of July 2019, there was a very unusual opening on 50 MHz between Europe and New South Wales in SE Australia.
Here are some of the send/receive reports from PSK Reporter for the Australian stations on the 50 MHz band...
VK3ZL...
A successful FT8 contact was made between VK3ZL and EI3KD in Ireland, a distance of 17,375 kms. This seems to have been the longest contact of the day.
VK3BD...
VK3ANP...
VK3ZYC...
VK3EW...
The opening from Europe to SE Australia seemed to be from about 07:09 UTC to about 08:20 UTC.
The graphic below shows where the sun was shining at 07:30 UTC.
Some notes....
1) Solar..... The solar flux was way down at 67, the sunspot number was zero and there was no sign of any type of enhancement due to a flare. It's hard to imagine there was any normal type F2 propagation which might be seen around the peak of the sunspot cycle.
2) Japan..... The opening from Europe to Australia seemed to coincide with an opening from Europe to Japan. S57RR in Slovenia was on the send/receive list for five of the six VK3 stations and this is what the 6m map was like for him on the 24th...
3) Multi-hop Sporadic-E ???.... The distances worked from Europe to Australia were in the region of 16,000 to 17,400 kms. If it was simple multi-hop Sporadic E, it would require something like eight to nine hops. What are the chances of this many Sporadic-E hops? I find it hard to believe it's possible.
4) Winter..... It's worth noting that it's winter in Australia and this is not their Sporadic-E season. There seems to be no sign that the VK3 stations were hearing any other stations via Sporadic-E, just the opening to Europe.
Theory?...... Just a thought and I'm putting it out there for others to consider. Is it possible there was TEP (Transequatorial propagation) opening from SE Australia to an area SE of Japan and then became skewed via Sporadic-E? The multi-hop Sporadic-E opening from Europe also got to this region in the Pacific?
It's possible the TEP path may have been a bit more westerly from Australia to an area closer to China.
Perhaps it's grasping at straws for an explanation but I find it just as feasible as expecting 8-9 Sporadic-E hops to line up in a row at 50 MHz for the shorter direct path.
The key difference between the two paths would of course be if the beam headings for all parties were the most direct short path ones or if they were skewed. Unless someone is using a long Yagi, it may not be so obvious at 50 MHz.
All good material for debate of course but probably impossible to prove one way or the other.
Addendum : See message below from Brian, VK3BD (Added 12th Aug 2019)...