Big opening on 50 MHz between South Africa & Europe - 23rd Oct 2021

Saturday 23rd October 2021: I was first alerted to this big opening on the 50 MHz band between Europe and South Africa when Tom, SP5XMU posted the map on the left on Twitter and tagged me.

This is a snapshot of FT8 signals on the 50 MHz over a short period but it clearly shows an opening in progress.

As well as posting the photo, Tom writes... "First solid Trans-Equatorial Propagation #TEP on 50 MHz in Solar Cycle 25 from south Europe to South Africa"

In this post, we'll look at the opening and keep a record of how extensive the opening was.

FT8: As per usual, FT8 was the dominant mode for the opening and the list below shows how many European stations were heard by each of the African stations.

Call - # of stns heard

ZS6NJ - 86 (10 DXCC)

ZS6NK - 79

ZS6WAB - 53

ZS6AF - 44

ZS6OB - 23

ZS6JGL - 18

V51WC - 16

ZS6BOS - 15

ZS4TX - 6

ZS6AYE - 5

ZS6NK: While ZS6NK was the second highest in terms of stations heard, it was interesting to see that the path for him extended beyond the usual TEP zone.

You can see the line of stations in the south of Europe that ZS6NK heard but it goes up to the UK and Germany as well.

Here is the map of Europe in more detail...

FT8 reports from Germany & England...

Txmtr Rcvr Band Mode Distance Time (UTC)

ZS6NK G0BNR 6m FT8 8965 km 14:45:26

ZS6NK DK8NE 6m FT8 8489 km 15:34:59

ZS6NK DL1YM 6m FT8 8370 km 15:34:59

It's likely that there was some Sporadic-E which allowed the TEP signals from Africa reach further north into Europe.

Sometimes, the locations where there are no signals can be interesting as well. For example, there was no path for ZS6NK to Slovenia, Croatia, Serbia, Bulgaria and Romania. Likewise in South Africa, it was the stations in the north of the country that were enjoying the TEP opening and there was no sign of the stations further south near Cape Town.

Namibia: V51WC in Namibia was also active and his FT8 is shown below...

Like the stations near in the north of South Africa, he is far enough north to avail of the TEP opening.

SSB & CW: Looking at the DX Cluster, there was some activity on SSB and CW as well. See below...

The DX cluster spots for V51 & ZS on the day are shown below. Non-FT8 are in bold...

Video: Modes of Propagation on 50 MHz by K9LA

In June of 2021, Carl Luezelschwab K9LA gave a presentation to the Madison DX Club titled 'Modes of Propagtion on 6 meters'.

There are plenty of guides and explanations about propagation on the 50 MHz band in books and on websites and they tend to be pretty basic. In this video, K9LA looks at propagation modes in more detail and as expected, things are often not as simple as they seem.

It's very easy to look at long distance contacts on the 50 MHz band and just blindly assume it has to be multi-hop Sporadic-E. As you will see in the video, we should all keep an open mind and accept that it may be due to other propagation modes. This is especially true now as the FT8 digital mode is showing that weak signal paths exist that weren't so obvious in the past with SSB or CW.

The 51 minute video can be seen below...

Some timestamps and items of interest...

00:00 to 02:20 Introduction

02:20 to 04:20 Old 50 MHz radios

The talk is then broken down as follows...

Review of all these modes
Antenna considerations
Solar Cycle 25
References

04:50 to 09:30 Fundamentals of the atmosphere and ionosphere.

It's interesting to note that K9LA questions if PMSE (Polar Mesospheric Summer Echoes) at 85kms above the Earth plays a part in bending radio signals slightly before they reach the higher Sp-E and F2 layers.

In the slide for trospheric ducting, there is an error in that it should read 450 metres as opposed to 450 kms. As K9LA observes, tropo ducting at 50 MHz is very unusual in temperate regions.

At 15:45, K9LA talks about SSSP - Short-path Summer Soltice Propagation which is linked to PMSE. It may well be that this propagation mode is responsible for many of the openings from Europe to Japan on 50 MHz as opposed to the standard 'it must be multi-hop Sporadic-E explanation'.

At 27:30, there are charts suggesting that Sporadic-E may be changing over the years.

At 32:00, Carl suggests that equatorial Sporadic-E may be a significant factor where signals are crossing the equator at local noon.

At 36:00, the video looks at Chordal Hop modes. As the image below shows, there can be a lot more going on than just simple hop Sporadic-E...

At 41:00, skewed paths are examined.

45:20 Antenna considerations

46:50 Cycle 25 status

Links...

1) I have some examples of unusual long distance paths on the 6m band on my 50 MHz page.

50 MHz South Pacific Summer Propagation season 2020-2021... by CE3SX

Back in mid-December 2020, I had a post up on the blog about some remarkable openings on 50 MHz between Australia and South America with some contacts were up to 13,000kms in length... https://ei7gl.blogspot.com/2020/12/remarkable-13000-km-opening-on-6-metres.html

Pipe CE3SX in Chile has now compiled his own report on the 50 MHz South Pacific Summer Propagation season 2020-2021.

The report covers 6m openings from Chile to Australia & New Zealand from the 8th of December 2020 to the 23rd of January 2021.

In summary, CE3SX in Chile completed 77 QSO's on 50 MHz across the South Pacific... 47 with New Zealand (ZL) which is obviously closer, 26 with Australia (VK) and 4 with the Chatham Islands (ZL7).

64 of the contacts were via the JT65 digital mode, 9 via FT8 and 3 via FT4.

The first contact of the Summer season was to ZL1RS on the 8th of December 2020 which was also the first South America to Oceania 50 MHz contact of the season.

The first contact to Australia was to VK4MA on the 9th of December 2020.

The longest contact was with VK4BLK which was 12,380 kms in length.

The map above shows the locator squares worked by CE3SX on 50 MHz during the 2020-2021 South Pacific Summer Season.

Mode of Propagation???... The maximum distance for one Sporadic-E hop is about 2300 kms. If all of these 10,000 to 12,000km openings were due to multi-hop Sporadic-E then a lot of patches of Sporadic-E had to line up in a row and at the correct distance for it to work.

It has been suggested that part of the propagation path may have been to Polar Mesospheric Summer Echos (PMSE) with electrons gathering around ice crystals.

The full report from Pipe CE3SX can be seen here... https://www.qsl.net/ce3sad/SPSP.html

Unusual 50 MHz opening from Australia to Europe - Wed 24th July 2019

Over the last few weeks, there have been multiple openings from Europe to Japan at 50 MHz as stations make use of digital modes like FT8 to dig weak signals out of the noise. Most of these contacts are in the region of 9,000 to 10,000 kms which suggest multi-hop Sporadic-E was the likely propagation mode.

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.

The opening seemed to coincide with sunset in SE Australia.

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)...

WSPR on 50 MHz...

Over the last 2 weeks or so, I have used WSPR on 50 MHz and I have heard several stations....mainly Western European countries and a bit of DX in the form of CN8LI in Morocco.

The screenshot above is from 50 Mhz today (23rd May 2011). No WSPR stations heard but you can see the lines above about 5Hz apart. At first, they might just look like some sort of computer interference but these are actually TV carriers. The band was open to Eastern Europe and the TV transmitter was probably located somewhere there. Looking at the DX-Cluster and listening down lower in the band, then it was certainly open to Poland and the Czech Republic at the time.

It also shows the limitations of WSPR on VHF.....band was open yet no WSPR stations heard. Outside of Western Europe and the USA, there is certainly a lack of activity from other areas.