Following on from the 3051km opening on 144 MHz across Australia on the 24th of December 2022, there was also a 3385 km opening on the Christmas Day, the 25th of December 2022 from Adelaide to New Zealand.
There is an active group of radio amateurs in Australia and New Zealand using the WSPR mode on the 144 MHz band to investigate propagation paths. On Christmas Day, VK5PJ in Adelaide managed to get just one WSPR decode from ZL2GT on the North Island in New Zealand.
2022-12-25 09:12 ZL2GT RF80 VK5PJ PF95mk 144.490498 10 -18 0 3385
Leigh VK2KRR reports... "144 MHz antics for some operators yesterday. Peter Sumner VK5PJ and ZL2GT topping the maximum distance at 3385 km via Sporadic E.
There was a number of other E paths and tropo as well. Another path of note is Nigel VK6CPU at Perth on a path with Phil VK5AKK tropo path at 2140 km. Its rare to get paths into and out of Perth on tropo, but it does happen on rare occasions.
A few days back i missed reporting on a tropo path from Alan Johnson VK3DXE to VK6CPU/P of 2442 km. Alan was the only station in VK3 who made it on this path on 23.12.22."
Analysis... The extreme distance of this opening i.e. 3385 kms, cannot be explained by a single Sporadic-E hop which tends to max out around 2300 kms.
This is the tropo forecast for the 25th of December 2022 from F5LEN...
It does suggest that there were some tropo conditions in the Tasman Sea but it's not conclusive. It's probable that the western path of the path was certainly due to Sporadic-E but as for the eastern half, it may have been due to a tropo extension over the Tasman Sea or it may have been a second Sporadic-E hop i.e. possibly chordal hop Sporadic-E.
People may have different opinions on which it is but it's almost impossible to tell.
1) Examples of more long distance contacts on 2m can be found on my 144 MHz page HERE
