5000km+ TEP opening on the 432 MHz band in the Indian Ocean - 23rd Apr 2024

 Back on the 8th of April 2024, I reported on the very first Trans-Equatorial Propagation (TEP) opening on the 144 MHz band from UAE to Reunion Island in the Indian Ocean. Since then, this has been pretty much a daily occurence and I have been keep a record of the openings.

On the 23rd of April 2024, A65BR in the United Arab Emirates (UAE) reports that his 432 MHz signal was heard in Reunion by FR4OO via TEP. The distance was in the region of 5160kms.

Reports of TEP openings on the 70cms are incredibly rare and it's really interesting to hear about this new report. In this case, it was only a reception report but it shows the potential of the path at 432 MHz.

The composite image above shows reception of the Q65 signal at -17dB as heard by FR4OO.

TEP at 144 MHz is common enough for stations in the right location but stations using 432 MHz are really pushing the limits at what's possible. There are many different propagation modes on 70cms but surely one that allows 432 MHz signals to propagated by the ionosphere must be one of the more unusual ones.

It would be good to see more stations experimenting with TEP at 432 MHz and seeing what it possible.

Link...
1) For more examples of long distance openings on the 70cms band, see my 432 MHz page.

First TEP contact at 144 MHz made from Mauritius - 9th Apr 2024

On the 9th of April 2024, 3B8FA in Mauritius made the first Trans-Equatorial Propagation (TEP) contact on the 144 MHz band from that country when he completed a contact with A65BR in the UAE. As the screen grab shows above, there was also a path to A71XX in Qatar.

This screen capture below from Oleg, A65BR shows the contact on the Q65 mode.

FR4OO on Reunion Island also had the same TEP as the previous day to A65BR, A71XX and 9K2GS.

Just to keep the report as complete as possible, there was also a path from FR5DN to Qatar...

Looking at the maps, there is almost certainly a TEP path from Madagascar (5R) north to Kuwait but it just needs someone to be active from that country.

Links...

1) See my 144 MHz page for more examples of long distance contacts.

First ever TEP contacts made at 144 MHz in the Indian Ocean - 8th Apr 2024

On the 8th of April 2024, a little bit of amateur radio history was made with the first ever TEP contacts on the 144 MHz band in the Indian Ocean.

Over the last few decades, Trans-Equatorial Propagation (TEP) contacts on the 144 MHz (2m) band have been reported from South America to the Caribbean area, from the southern part of Africa to the Mediterranean area and from the north of Australia to Japan. This is as far as I know, a first for the Indian Ocean.

Inspired by the recent TEP contacts from Namibia to the south of Europe, other radio amateurs are trying other potential TEP paths. On the 7th of April 2024, A65BR in the UAE reported reception of the signal of FR4OO on Reunion Island... see previous post. On the 8th of April, three successful contacts were made as shown above.

The contacts are similar to other recent TEP contacts... made in the late evening, approx 5200km north-south path, equidistant from the Geomagnetic Equator and using Q65 to handle the distortion and weak signals.

The first contact was made by Oleg, A65BR around 16:30 UTC...

Oleg, A65BR writes... "Today TEP to FR on 2m was amazing. Q65 QSO with FR4OO done. Never try before, looks like we have permanent channel via TEP on 2m. Signals are huge, CW can be easy."

Oleg continues... "Today a QSO took place without any problems, the opening lasted 2.5 hours, the signal rose to -2 dB, FR4OO also worked 9K2GS and A71XX. Tomorrow 3B8FA will join their side, I hope it will grow together. It all started at 16.20 utc, (20.20 local Umm Al Quwain) and until 23 pm. It’s interesting to try at 70 cm.

According to the terrain - FR4OO sees the ocean, but I don’t - I have 1000 km to the ocean and the Omani hills on almost the entire route. However, it doesn't hurt!"

Alex, SV1NZX reports... "FR4OO completes with 9K2GS, A65BR and A71XX on 2m. FR5DN hears A71XX for one period. Congratulations to all stations!!"

As Alex mentions, the signal from a second Reunion Island station (FR5DN) was also heard in Qatar (A7).

These are the spots from the DX Cluster...

A71XX 144192.0 FR4OO 16:56 08 Apr FT8 LL55rw - LG79rc Reunion Island
9K2GS 144192.0 FR4OO 16:53 08 Apr  Reunion Island

Analysis... If the recent TEP openings to Europe are anything to go by, these openings in the Indian Ocean should be almost a daily occurrence for the few weeks around the equinox. This path is probably there year after year but it just takes someone at either end of the circuit to try it.

Links...

1) See my 144 MHz page for more examples of long distance contacts.

5160km TEP opening at 144 MHz in the Indian Ocean from Reunion to UAE - 7th Apr 2024

With the success of the now almost daily TEP openings on the 144 MHz band from Namibia to Europe, it has encouraged others to try similar possible TEP paths.

On the 7th of April, Olen A65BR in the United Arab Emirates reported reception of the 144 MHz signal  from FR4OO on Reunion Island. The distance is around 5,160kms.

The screen grab above from A65BR shows several decodes of the Q65 signal. As far as I know, it was a one way reception report and a two way contact did not take place.

This is as far as I know a new TEP path and hasn't been reported before. Hopefully, it might encourage others to try some tests on the 144 MHz band.

Links...

1) See my 144 MHz page for more examples of long distance contacts.

Extensive opening on 50 MHz from the UAE - 27th June 2021

On the 27th of June 2021, A65BR in the UAE posted on Twitter that he was hearing both Japan and the USA at the same time on the 50 MHz band.

This is an extract from the PSK Reporter website which shows it was open to Japan the USA.

A65BR JH8XTZ 6m FT8 7776 km 12:53:14
A65BR JA8XTG 6m FT8 7785 km 12:58:14
K4RX A65BR 6m FT8 12491 km 13:00:56

As can be seen from the map above and the PSK Reporter site, it's nearly 8000kms to Japan and over 12,000kms to the USA.

If we were to subscribe to the multi-hop Sporadic-E model of propagation then we would believe that there was 4 hops to Japan and 6 hops to the USA at the same time on the 50 MHz band. What are the chances of that?

I wonder if the amateur radio community are too quick to assume everything is 'Sporadic-E' during the Summer months?

3000km+ opening on 144 MHz between the United Arab Emirates and Europe - 5th June 2021

Almost but not quite:  On the 5th of June 2021, Stamen LZ1KU in Bulgaria and Oleg A65BR in the United Arab Emirates almost managed to complete a FT8 contact on 144 MHz over a distance of 3,280kms.

While both stations managed to get some successful decodes, they were unable to complete a contact on this occasion.

The composite screen above from LZ1KU shows a decoded FT8 signal from A65BR at -20dB. An earlier decode at 14:48 UTC was at -16dB. The exchange shows A65BR giving a signal of -13dB for LZ1KU.

2021-06-05 14:48:58Z   LZ1KU Stamen FT8 144445 -16 dB 0.3 s Freq 1369 Hz > CQ A65BR LL75

In the examples above, the FT8 signal would have been below what is really audible to the human ear so a contact on CW would have been very unlikely.

A65BR also spotted LZ1KU on the DX-Cluster...

 Spotter Freq. DX Time Info Country
A65BR 144174 LZ1KU 14:37 05 Jun 21 LL75SL<ES>KN32AH CQ HRD Bulgaria

LZ1KU was reported to be using 'full power' to 4 x 12-element Yagi array while A65BR was using 50-watts to a 7-element.

Amazingly, IZ7AUH in the south of Italy also managed to get a decode from A65BR over a distance of almost 3,900kms.

Propagation Mode: Both paths were well in excess of the 2300kms or so we might expect from one hop Sporadic-E so how can we explain it?

The tropo prediction map from Pascal, F5LEN shows some excellent conditions in the Arabian Gulf so it is probably no great suprise that the 3000km+ paths were in that direction.

One scenario is that there was a tropo duct over the Arabian Sea and this then coupled into a single hop Sporadic-E opening to Bulgaria. For the Italian station, it would require another few hundred kms of tropo at the western end of the circuit to complete the path.

Another scenario was that it was Chordal Hop Sporadic-E with the 144 MHz signal bouncing off two Sp-E clouds that were in just the right location. There was an extensive Sporadic-E opening from Israel into Europe so the MUF was high in the region.

And just to add another variable into the mix, the International Space Station was around at the same time (or at least I think it was based on an observer in Ankara).

It's hard to know for sure what the exact propagation mode was. It's a bit like a science experiment and we have just two data points. It's easy to make assumptions but we just don't know. 

For me, the main thing is that it is yet another example of a 3000km+ path on the 144 MHz band.