28th January 2021: There was another 3000km+ opening on 144 MHz between Australia and New Zealand when Peter, VK5PJ in Adelaide received the WSPR signal from Bob, ZL1SIX.
The two WSPR decodes are shown below and the signals were pretty weak at -19 and -20dB.
UTC (y-m-d)TXtxGridRXrxGridMHz W SNR driftkm 2022-01-28 01:06 ZL1SIXRF64vtVK5PJPF95mk144.490537 10 -21 0 3155 2022-01-28 01:12 ZL1SIXRF64vtVK5PJPF95mk144.490537 10 -19 0 3155
The map above shows the WSPR signals heard on 144 MHz by VK5PJ over a 24 hour period. Most of the Australian signals are tropo but the 3155km distance was really something else.
Remember, 3155kms is the distance between Ireland and Newfoundland across the North Atlantic.
Propagation??... It's important to note that VK5PJ was the only station in Australia to hear ZL1SIX on 144 MHz that that. i.e. none of the closer stations near the south-east coast heard him. This does suggest that Sporadic-E was the main propagation mechanism.
One single Sporadic-E hop might account for a maximum of say 2300kms but not 3155kms. What makes up the difference?
The map above shows the tropo prediction from Pascal, F5LEN and it suggests that there might have been some tropo ducting over the Tasman Sea.
It's possible that the western path of the 3155km path was due to Sporadic-E and that coupled into a maritime duct for the remainder of the circuit to New Zealand.
A second option was that it was due to chordal hop Sporadic-E with the signal going between two Sporadic-E 'clouds'. This does happen at 144 MHz but it is relatively rare.
It's impossible to know for sure what the propagation mechanism was but the probability of a combined Sp-E / tropo duct opening is higher.
Link... 1) More examples of long distance paths can be found on my 144 MHz page.
23rd December 2021:At the moment, stations in the southern hemisphere are in the middle of their Sporadic-E season and at times, there are openings as high as the 144 MHz band.
The above is an example of what looks like a mixed propagation mode opening between New Zealand and the south-east corner of Australia.
ZL1SIZ in the far north of New Zealand was sending out WSPR signals on 144 MHz and these were received by four Australian stations with distances in the range of 2451 to 2575kms.
How do we know it was likely to have been Sporadic-E? All of the reception spots are shown above and they are all from a small time window with just six minutes for the stations in Victoria. If it was 100% tropo ducting then we might expect to see more reports over a much longer time period.
How do we know it was likely to be due to mixed propagation mode? Simply because the distance is further than what is possible with one Sporadic-E hop... i.e. about 2300kms.
The tropo prediction map from F5LEN suggests that conditions were reasonable over the ocean at the New Zealand end.
ZL to VK6 on 144 MHz??? While the opening or distance described above isn't that exceptional, it does give a hint at what might be possible at some stage.
A few days ago, I had a post up about about a 2700km opening from Western Australia to New South Wales. Now the example above shows an opening from Victoria to New Zealand.
Is a 5000km opening on 144 MHz between New Zealand and the west of Australia possible???
There are often tropo ducts in the Great Australian Bight to the south of Australia and in the Tasman Sea between Australia and New Zealand. Could some exceptional Sporadic-E opening coincide with a large tropo duct?
Best mode??? WSPR with its two-minute transmission cycles probably isn't the best mode for this as the Sporadic-E openings along the route may be short in duration. Having said that, the guys in Australia and New Zealand have a very successful WSPR network going on the 144 MHz and the information from the WSPR reports could show what parts of the path are open. It may be down to individuals then trying to make contacts on the FT8 or Q65 frequencies.
Links... 1) For more reports on long distance paths on 2m, see my 144 MHz page.
On the 1st of December 2019, there was an extensive Sporadic-E opening on 144 MHz in the south-eastern part of Australia. While this allowed contacts on the 2-metre band between various Australian regions, the most remarkable opening was probably between Adelaide (VK5) and the northern tip of New Zealand.
Both VK5GF and VK5AKK managed to hear the WSPR beacon ZL1SIX, a distance just over 3,170 kms and a remarkable distance for 2-metres. To explain that from a European perspective, that is the same as say London to Cyprus or across the North Atlantic from Ireland to Newfoundland.
Mode of Propagation???... Normally the maximum distance for one Sporadic-E hop is about 2,300 kms so this alone cannot account for the 3,174 kms covered.
There were other reports of some double hop Sporadic-E on 50 MHz between Australia and New Zealand so perhaps it reached as high as 144 MHz as well? While it is not impossible, it would be highly unusual.
Another possibility was that there was a single hop Sporadic-E hop from Adelaide to the east and then the rest of the path was via a tropo duct to the North of New Zealand. It's impossible to tell though.
ZL1SIX Beacon... This WSPR beacon is located 370 metres above sea level and runs 10 watts into four stacked 3-element beams pointing west towards Australia (pictured on the left).
Beacon Info) Two metre WSPR transmitter: QTH: Manginangina, 13km (8 miles) west of Kerikeri at 370m (1200 feet) ASL overlooking the Bay of Islands, New Zealand Frequency: 144.490540 MHz (GPS calibrated) Ident: Standard WSPR transmission followed by ZL1SIX RF64VT in Morse code. Current operating conditions: 10W RF output into 4 x 3 element Yagis facing West (13dBi). EiRP = 200W Equipment: QRP-Labs U3S with a TCXO on the synthesizer board, Tait T198 PA module, QRP-Labs QLG1 GPS unit More info here... https://www.qsl.net/zl1rs/bcn_ant.html
Extract from the report on Facebook by VK2KRR... "Yesterday we had the BRILLIANT situation, where we saw a high MUF sporadic E area highlighted on 6m WSPR, which quickly escalated to showing 2m sporadic E paths going north and south across this area, also initially detected on 2m WSPR between VK7 stations and VK2, which is quite a high MUF down to 1000 km distance for some of the paths. Since the first 2m Sporadic E opening found just over a week ago, we have found an opening on 2m almost every day! At this stage I am not sure if its because of all the signals and data being shown by WSPR operations that we have been able to better locate areas of high MUF sporadic E and make use of it, or if it's just an extraordinary series of events that's been going on. I don't recall seeing such regular E openings on 2m here in the past, they are usually quite a rare thing." ... VK2KRR on Facebook.
Video... This video from VK7HH in Tasmania shows some of the openings on 50 MHz and 144 MHz. (The 2m opening starts around the 4 min mark)...
Addendum... It looks as if another 3000km plus path opened up again on the 6th of December 2019 in Australia.
This time, the WSPR signal of VK2DVM in Sydney was heard in the south-west corner of Australia, a distance of some 3,102 kms.
Note the signal... -27dB! This shows the value of WSPR in that it allows the discovery of paths on the VHF bands which would have gone unnoticed before.
As for how, it was most likely a mixed Sporadic-E and tropo signal. i.e. One Sporadic-E hop from VK2DVM so that the signal reached the Great Australian Bight and then via a maritime tropo duct to VK6NI.
