Showing posts with label SP4K. Show all posts
Showing posts with label SP4K. Show all posts

Saturday, April 30, 2022

50 MHz openings to South Africa start as the Sporadic-E season begins - 29th Apr 2022


On the 28th of April 2022, Chris SP4K in Poland reported that there was an opening on the 50 MHz to South Africa, a distance of almost 9000kms.

Chris writes... "The 2022 6m DX Season is officially open here in KO03. Short Es linked TEP to ZS resulted in two QSOs in the log - ZS6NJ and ZS6AF".

The Trans-Equatorial Propagation (TEP) season tends to peak around the equinox while the Sporadic-E season peaks during the Summer months.

Late April and early May can be a very good time for North-South paths as the two seasons overlap.

Explanation... For stations in Spain, Italy & Greece, they are far enough south to be able to to exploit 50 MHz TEP openings to the south of Africa. Stations further north are too far away for TEP but that changes when the Sporadic-E season starts and there is an opening to the south.

This allows northerly stations to now access the TEP zone further south. This can be seen in the map above. The usual Sporadic-E zone of signals in the 1000-2000km range are shown. For SP4K, there was an opening to the south by Greece and then onto the TEP zone over Africa.

This is the situation for all northerly stations in Europe or the USA and Canada. Late April and early May is the time to beam south and look for those openings to the southern hemisphere.

Log for SP4K...

 Txmtr Rcvr Band Mode Distance Time (UTC)
SP4K ZS6NJ 6m FT8 8909 km 16:35:42
SP4K ZS6OB 6m FT8 8880 km 16:36:14
ZS6AF SP4K 6m FT8 8867 km 16:39:28
SP4K ZS6WN 6m FT8 8678 km 16:39:14

Thursday, June 3, 2021

15,000km opening on 50 MHz between the Canary Islands & Guam in the Pacific - 3rd June 2021


Thursday 3rd June 2021: Another day, another 15,000km opening on the 50 MHz band.... well almost. This time the longest opening seen on the PSK Reporter website was the 14,966km path between KG6DX on the island of Guam in the Pacific and EA8DBM on the island of Tenerife in the Canary Islands.

EA8/DF4UE on the neighbouring island of Lanzarote was just 150kms behind.

I checked the PSK Reporter site and there were paths open for both to multiple stations in Japan as well. IF the signals took the direct path then they crossed over the north of Russia.

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.

SP4K 6m FT8 14993 km 07:43:30
LY2BAW 6m FT8 14683 km 07:46:59

***

There was a much bigger opening from VK4ABW on the north coast but he is also quite a bit closer with distances just over 12,000kms.

VK4ABW SM7CAD 6m FT8 12650 km 09:11:56
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

***


The longest paths came from the south-east of Australia. VK3OT was hearing the Ukraine.

UR5LAK VK3OT 6m FT8 14102 km 05:57:11
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

SP4K VK3ZL 6m FT8 15459 km 05:20:44
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.