6474km TEP contact on 144 MHz from Argentina to a ship off the coast of Florida - 9th Dec 2024

Over the last few years, I've reported on many Trans-Equatorial Propagation (TEP) contacts from South America to the Caribbean on the 144 MHz band... links on my 144 MHz page.

For this mode of propagation at 144 MHz, signals must generally cross the Geomagnetic Equator at right angles. This usually means that stations in the south of Brazil work places like Guadeloupe, St Martin & Puerto Rico. Stations near Buenos Aires in Argentina work stations in Curacao & the Dominican Republic.

There has been a distinct lack of 144 MHz TEP openings further west in South America mainly due to a lack of stations at one or both ends of the paths.

So it was a really big surprise to hear that Carlos, LU7MC in the west of Argentina managed to complete a contact with Yuri, UT1FG/MM on a ship to the north of Cuba!

The contact was made using the Q65B mode on the 9th of December 2024 at 01:34 UTC. This is just after 20:00 local time for both stations which is about the peak time for evening type TEP.

The distance was in the region of 6474 kms which is exceptionally long for a 144 MHz TEP contact for South America.

The map above shows just how close UT1FG/MM  was to the Florida. His ship was just 80kms south of the road going to Key West and about 170kms south of Miami.

It's hard to know for certain but I suspect that the TEP signal from LU7MC almost certainly reached Florida. It was most likely that there was nobody active there and looking.

Mode of Propagation... As indicated already, the mode of propagation was TEP - Trans-Equatorial Propagation. There may have been an extension at the northern end of the circuit with some marine tropo / ducting north of Cuba.

Mode of contact... The Q65B mode was used for this 144 MHz contact. The screen shot from LU7MC is shown below...

As you can see below, the signal level was about 0dB to -8dB which is probably too weak for SSB but should be strong enough to be heard by ear and a CW contact would be possible.

The screen shot from UT1FG/MM is shown below...

The signal levels were about the same at -4dB to -8dB.

Equipment... Carlos, LU7MC is located in the city of Mendoza in grid locator square FF57OB. He was running 100-watts into an array of 4 x 10-element Yagi antennas.

Yuri, UT1FG works on a commercial ship and was Maritime Mobile between Cuba and Florida in grid locator EL94PC. He was running 200-watts into a single 7-element Yagi antenna.

In conclusion... This really was an important contact on the 144 MHz band because it shows that there is a very good possibility of a TEP path from the west of Argentina to Florida. Could it extend even further north to some of the other southern US states by tropo? Could the stations in Chile get in on the action?

The really big question is if anyone in the United States is paying attention and is going to try and make a contact?

Link...
a) For more information on long distance 2m contacts, see my 144 MHz page.

TEP openings on the 144 MHz band from St Helena Island to Europe - Oct 2024

Back at the end of September 2024, I had a post on the blog about the first TEP contact on the 144 MHz band between Spain and St Helena in the South Atlantic, a distance of about 6,100 kms - Post HERE.

Just after that, other stations in Spain and Portugal were making TEP contacts with St Helena so I waited for the end of October to do a proper report.

First of all, I must give credit to Gabriel, EA6VQ who collects a list of TEP openings on his website... https://www.dxmaps.com/

As with all data, it's hard to know from just raw information what is going on. So I took the information and generated the map that is shown above to give a better idea of what happened during the month of October 2024.

Some notes...

1) # of Days... Out of the 31 days of October 2024, there were 22 days where Trans-Equatorial Propagation on 144 MHz was reported between St Helena and the Iberian peninsula. As Garry, ZD7GWM is the only person active on 144 MHz from St Helena, any reported activity obviously depends on him being active. 

There were also a few days where TEP didn't seem possible due to geomagnetic disturbances. 

Still though, it's remarkable that there was a TEP path on 144 MHz to St Helena on two-thirds of the days of the month.

2) Mode... The initial contact with EA4I last month was with the FT4 digital mode. They are now using modes more suitable for TEP. For the first half of the month, the Q65-30B mode was used while the Q65-60D mode was used in the second half.

3) Right Angles... At 144 MHz, the TEP paths cross the geomagnetic equator close to 90-degrees. This is where the value of map becomes a reality because we can see the spread east and west of the stations involved.

Most of the stations at the northern end of the TEP circuit are in Portugal and the EA4 & EA7 regions of Spain. It's interesting to see EA3CJ in the NE of Spain is the outlier and well to the east of the rest. 

4) Missing signals?... Sometimes, it's the missing signals that are interesting. There were no reports from the EA1 area in the NW of Spain. Too far north? There were also no reports from the EA5 or EA6 areas. Too far east?

5) Distances... The longest distances are in the region of 6,300 to 6,400 kms. A total of 17 stations were involved at the northern end of the TEP path. Even UT1FG/MM on a ship to the west of the Straits of Gibraltar managed to get in on the action!

CT1EEB IN50qr 6315km

CT7ABA IN60GD 6246km

CT1FCX IM59LG

CT1APE IM59kj

CT1FFU IM59kk

CT1DIZ IM58kp

CT1CAD IM67GE 

UT1FG/MM IM55

EA3CJ JN01SE 6403km

EA4GDA IM68MV

EA4I  IM68MU

EA4LU IM68TV

EA4CYQ IM78CX

EA7/SM0KAK IM76mm

EA7BPO  IM76SR

EA7HLB IM76OP

EA7FDW  IM76WS

6) Times... As is typical with evening type TEP, most of the signals were around 8pm local time. The earliest report was at 19:38 UTC and the last report was 21:32 UTC.

7) ZD7GWM... As far as  I know, Garry, ZD7GWM on St Helena has a modest station with just 50-watts from a Yaesu FT-897 into a Diamond X700H vertical antenna.

Analysis... I've been following the TEP tests in 2024 and it has been pretty remarkable just how often the path is there on 144 MHz. I think a lot of people expected it to be more sporadic but it often seems like TEP at certain times of the year is almost a daily occurrence.

Looking at the map, I think a lot of people will be wondering just how far north could this TEP path reach? Is it possible to reach the north of Spain? Could another propagation mode take the TEP signal further north to the likes of Ireland, Wales & the SW of England?

Sporadic-E would be an obvious answer but it's very unlikely at 144 MHz at 8pm on an evening in October. A maritime duct from Ireland to the north of Spain is more likely but signals don't seem to get too far inland into Spain.

It's very likely that the TEP signals from St Helena are in the north of Morocco but there is no-one there to exploit it.

I have a previous post about Garry's set up HERE

For more information about other long distance openings on the 2m band, see my 144 MHz page.

6100km TEP contact on the 144 MHz band between Spain and St Helena - 25th Sept 2024

A little bit of history was made on Wednesday 25th September 2024 when EA4I in Spain and ZD7GWM on St Helena Island in the South Atlantic managed to complete a Trans-Equatorial Propagation (TEP) contact on the 144 MHz (2m) band.

This is as far as I know the very first TEP contact on the 144 MHz band between these two countries.

José, EA4I in the west of Spain was running 700 watts into an array of 4 x 17-element Yagi antennas. As far as I know, the polarization was horizontal.

Garry, ZD7GWM on St Helena had a much more modest station with just 50-watts from a Yaesu FT-897 into a Diamond X700H vertical antenna.

While many other TEP contacts are made with the Q65 mode due to the TEP spreading and distortion, this particular contact was made with the FT4 mode.

Andy, EA7KBX reports... "A new record was set tonight between EA4I Jose and ZD7GWM Garry - a small group of us have been running TEP tests from Spain to St Helena Island on 2m / 144Mhz the QSO was completed using FT4 at 6,094.22Km !! 

Jose using 4x 17 element beams and 700w while Garry was using a Diamond vertical and FT- 897 with just 50w !! Amazing contact for the record books"

Analysis... 2024 has been a pretty remarkable year for Trans-Equatorial Propagation on the 144 MHz band. For the last few years, there have been many reports of TEP openings from Argentina & Brazil in South America to the Caribbean area.

Some were claiming that it wouldn't be replicated in other parts of the world because the Geomagnetic Equator was too far north but that hasn't turned out to be the case. We've seen regular 144 MHz TEP openings this year from Namibia to Europe, the Middle East to the Indian Ocean and from Japan to Australia.

As long as both stations are roughly equidistant from the geomagnetic equator and the signal crosses the geomagnetic equator at about 90-degrees then a path is possible.

The biggest obstacle is getting someone active at either end of the TEP path. In this case, Garry, ZD7GWM is the only person active at the southern end of this circuit.

I'm sure if the antenna was upgraded to something modest like a 9-element Yagi fixed in a northerly direction then even more 2m TEP contacts with Europe should be possible.

I wonder if there are any VHF DX groups that help out DX stations with modest antennas?

I have a previous post about Garry's set up HERE

For more information about other long distance openings on the 2m band, see my 144 MHz page.

Video: Long-haul Ionospheric Propagation on 50 MHz - Roger Harrison, VK2ZRH

On the 14th of May 2024, Roger Harrison, VK2ZRH have a very detailed presentation titled 'Long-haul Ionospheric Propagation on 50 MHz' to the Madison DX Club.

In the video, Roger goes into quite a bit of depth about Sporadic-E propagation, Trans-Equatorial Propagation (TEP) and the complexities of both.

I think anyone who has an interest in propagation at 50 MHz or even in the low VHF region will find this presentation of interest.

The presentation is about 70 minutes in length and is shown below...

Link... See my 50 MHz page for other presentations and posts about some long distance paths on 50 MHz.

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.

Day 9: TEP opening on 144 MHz from Namibia to Europe - 8th Apr 2024

The Trans-Equatorial Propagation (TEP) openings from Namibia to Europe on the 144 MHz continued on the 8th of April 2024. The reports from the PSK Reporter website are shown above.

As can be seen from the list, this was quite a good opening and the one big change was the path to SV1DH near Athens in Greece. The horizontal spread of stations at the northern end of the circuit was in the region of 800kms.

At 144 MHz, the signals need to cross the Geomagnetic Equator at nearly 90 degrees for TEP and it gets a lot more difficult the further the station gets from 90 degrees. That's why it is interesting to see SV1DH listed.

The optimal TEP path from Athens is probably down to Zimbabwe but there are no stations active there on 144 MHz.

These are the spots from the DX Cluster...
IZ8FFA 144192.0 V51WW 19:09 08 Apr TNX Namibia
IT9XDJ 144192.0 V51WW 18:54 08 Apr Q65B -12 dB 1225 Hz  Namibia

Alex, SV1NZX reports... "V51JH heard SV1 and a smattering of other stations; ZD7GWM was cqing on 144.300 but sadly no copy from EA stations. SV1DH worked V51WW quite easily."

Felice, IZ8FFA reports working V51WW with 100W to a 12-element home made LFA Yagi on a 7m book.

Links...

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

Day 8: TEP opening on 144 MHz from Namibia to Europe - 7th Apr 2024

The Trans-Equatorial Propagation (TEP) openings from Namibia to Europe on the 144 MHz continued on the 7th of April 2024. The reports from the PSK Reporter website are shown above.

Interest is growing is these long distance TEP paths and more people are getting involved. In a previous post, I had details of how A65BR in the United Arab Emirates managed to hear FR4OO on Reunion Island via TEP on the 7th of April.

These are the spots from the DX Cluster...
IK7EOT 144190 V51WW 19:09 07 Apr 24 Q65B -18 Namibia
SV2DCD 144190 V51WW 18:27 07 Apr 24 CQ Q65B -15db TEP Namibia
SV8PEX 144190 V51WW 18:23 07 Apr 24 -09 q65b hrd in JM99 Namibia

Also on the 7th of April, the PSK Reporter website shows that IK7EZN in Italy reported reception of V51NH, the second station in Namibia. IZ7EZN is the only station reporting this so I'd be always wary of just one station reporting as someone may have made a mistake reporting the incorrect band.

It is also reported that ZD7GWM on St Helena is trying the TEP north to Spain (EA) & Portugal (CT). Stations in South Africa (ZS) are also beaming north.

SV1NZX in Greece reports... "Lots of TEP action tonight - V51WW seen/worked in at least 7 PSK-enabled stations, more saw him, reported via group chat, A65BR heard FR4OO, ZD7GWM was CQing dir EA. Overall 2xV5, a few from ZS (various areas) and ZD7 vs over 80 EU and AS stations

V Important.  AF stations are CQing 1st and EU 2nd. We implore that 144.190 is kept free of tropo QSOs and attempts for EU->EU on 1st period. Tomorrow, 9K2GS and A65BR will be testing with FR at 1630z, V5/ZS-EU from 1800z and ZD7GWM will be cqing .300U/301cw from 1930z dir EA"

Links...

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

Another 6000km+ TEP opening on 144 MHz from Namibia to Europe - 1st April 2024

As outlined in this previous post, there was a TEP (Trans-Equatorial Propagation) opening on the 144 MHz band between Namibia and Greece on the 31st of March 2024. As news spread that SV8PEX had been heard over 6500kms away in Namibia, more stations were active on the evening of the 1st of April.

This time, there were paths from Namibia to Greece, Italy and Malta and SV8PEX, 9H1TA and 9H1PA managed to complete contacts.

Alex, SV1NZX reports the following... "Tonight ends an exciting night for 2m #TEP QSOs - V51WW worked 9H1PA, 9H1TX and SV8PEX as well as receiving 4-5 other Italian stations in JN70, JN80. SFI measured at 125, K/A index at 5-8 and 1, all QSOs in Q65b, 30/60s."

This is a screen grab from SV8PEX in Greece...

This screen grab below is from V51WW and shows some of the exchanges with IK7UXW and IZ8EDJ  in Italy.

The screen grab below is from David, 9H1TX in Malta...

9H1TX writes... "Just finished my first TEP 2M qso with V51WW. I am totally closed to south but i elevated the system at 8 deg and was lucky to get his signal."

Analysis... As the map shows above, both stations are about equidistant from the Geomagnetic Equator and are crossing it at right angles, an important consideration for TEP signals at 144 MHz.

V51WW in Namibia is using 100w into a horizontal 9-element yagi 12m above ground level which is a pretty modest station. It shows that this TEP path to Europe is probably there a lot more often than people realise but the problem is that there weren't any stations in Africa to attempt a contact.

It would be interesting to see how far east and west in the Mediterranean the signal from V51WW can reach? How far from the 90 degree right angle at the Geomagnetic Equator can the 144 MHz signal go before it becomes impossible? EA6? IS0? 5B4? TA? SV5? SV9?

The Mediterranean is also an excellent location for tropo ducting. How far will that carry the signal north?

Are there any other stations at the southern end of the TEP zone? ZD7 (St Helena) to Spain seems an obvious one. Other paths?

It would be good to see more TEP reports from Europe to Africa on 70 MHz, 88-108 MHz and 144 MHz.

Links...

1) See my 144 MHz page for plenty of reports of other TEP contacts.

6530km TEP opening on 144 MHz from Namibia to Greece - 31st March 2024

 

Over the last few years, there have been many reports of contacts on 144 MHz from South America to the Caribbean region via Trans-Equatorial Propagation (TEP). There have been no reports of similar openings on 144 MHz from Europe to Africa in the same time period.

On the 31st of March 2024, it looks as if finally there was a TEP opening when V51WW in Namibia managed to receive SV8PEX in Greece, a distance of about 6532kms.

This is the report from the PSK Reporter website...

Txmtr Rcvr Band Mode Distance Time (UTC)
SV8PEX V51WW 2m Q65 6524 km 19:08:02

Tom, SV8PEX reports... "Unfortunately I was too late sig went down, one way. I was using 500W and V51WW I guess 100. Me -15db the best". Tom also notes that they tried FT8 and no decodes were possible.

Alex, SV1NZX writes... "First confirmed TEP reception of a signal between EU and AF tonight by V51WW from SV8PEX on 2m band after almost 40 years since the last signals between AF and EU intersected. Mode Q65a/30s "

V51WW is using 100w into a horizontal 9-element yagi 12m above ground level. SV8PEX is using 500w into a 11-element yagi 10m above ground level.

Analysis... As the map shows above, both stations are about equidistant from the Geomagnetic Equator and are crossing it at right angles, an important consideration for TEP signals at 144 MHz.

As SV1NZX mentions, there used to TEP contacts on 144 MHz from Europe to Africa back in the 1970's when there was activity from Zimbabwe. The key thing is the location. Zimbabwe and the north of Namibia are far enough north for signals to reach the TEP zone. There are plenty of stations in South Africa (ZS) active on 144 MHz but they are much further south.

In this particular case on the 31st of March, it was a reception report but it shows that a TEP path was open at 144 MHz. Hopefully more stations in southern Europe will now beam south and see if the path is open to Namibia and the southern part of Africa. 

It would be good to see more TEP reports from Europe to Africa on 70 MHz, 88-108 MHz and 144 MHz.

Links...

1) See my 144 MHz page for plenty of reports of other TEP contacts.

By the way, this is not an April Fools Joke! I know I posted it on the 1st of April so some might be wondering.

6,100km TEP opening on the 144 MHz band from Uruguay to the Caribbean - 21st Oct 2023

As we head towards the end of October 2023, there have been reports of some TEP (Trans-Equatorial Propagation) openings in South America on the 144 MHz band.

Carlos, CX5CBA in Montevideo, Uruguay writes... "As of the 21st of October 2023, there have been TEP openings every night for two weeks between South America and the Caribbean.

I have been able to make several contacts on 144 MHz on SSB and Q65 with a 4.7m long Yagi antenna and 50W. The stations worked are:

SSB: HI8D, HI8AN, HI8GSP, NP4BM
Q65: HI8D, HI3I, HI8T, NP4BM, PJ4GR."

The map above shows the path of one of these contacts between CX5CBA and HI8D. Note that the Geomagnetic Equator is almost equidistant from both stations and the path is at right angles to the Geomagnetic Equator as well. This is pretty much the ideal path for a TEP opening at 144 MHz.

The other stations NP4BM (Puerto Rico) and PJ4GR (Bonaire) are also located in the western part of the Caribbean. This follows the typical pattern for TEP openings in South America at 144 MHz... i.e. stations in Uruguay and Argentina work the Dominican Republic, Puerto Rico and Bonaire whereas stations in the south of Brazil usually work the eastern part of the Caribbean - Martinique, Guadeloupe, etc.

This is a log extract from CX5CBA...

It shows several contacts made on SSB which means the signals must have been reasonably strong.

You'll notice the one CW contact on the 50 MHz band to V31XX in Belize. With lower frequencies like 50 MHz, signals that are not as close to right angles can propagate.

This screenshot from Carlos shows that some on the contacts were made with the Q65 mode.

This screenshot shows the callsigns, signals and time. Note the time... about midnight UTC which is about 9pm local time in Uruguay.

Comment... Thanks for Carlos for the report and images. While these TEP openings at 144 MHz are pretty common, we should still remember that we are looking at contacts that are over 6,000 kms in length.

It's also a reminder that the TEP season is in full swing in South America and it's time to check out 50 MHz, 88-108 MHz and 144 MHz.

It would also be very interesting to see some stations doing TEP experiments on the 432 MHz (70cms) band.

Link... For more examples of long distance 144 MHz contacts, see my 144 MHz page.

FM radio station WMIA in Miami on 93.9 MHz is heard in Chile - 23rd Feb 2023

This reception report is from the 23rd of February 2023 when Pipe, CE3SX / CE3SAD in Santiago, Chile managed to receive the FM radio station WMIA in Miami, Florida on 93.9 MHz. 

The reception took place at 21:41 local time in Chile (22nd Feb) which is 00:41 UTC (23rd Feb). This is at the right time for an evening time Trans-Equatorial Propagation (TEP) opening.

What makes this highly unusual is the distance. It might be normal during an evening TEP opening for  FM radio stations in the north of Columbia to be heard in Chile but this time, the FM radio station was in Florida which is about 2000kms further north. 

In a previous post, I reported on how CE3SX had managed to hear FM radio stations in Jamaica in February of 2022. Florida is an extra 1000kms.

Florida is usually considered to be too far north for TEP propagation so how was the range extended to just under 6,700kms?

The first option that springs to mind was that it was an evening type TEP opening coupling into a tropo duct to the north to extend the opening to Florida. The tropo map above from F5LEN shows some tropo in the area but with the island of Cuba in the way, it's not exactly conclusive.

Is the most southern tip of Florida just close enough for TEP?

Have there been reception reports like this in the past?

And if it's possible on 93.9 MHz, what about 144 MHz from Florida to Chile? Is anyone trying?

Lots of questions...

Link... For more long distance reception reports on the FM band, see my 88-108 MHz page.

5300km TEP opening at 432 MHz reported from Curacao to Argentina - 24th Feb 2023

432 MHz TEP: In a previous post, I reported on how a signal on the 432 MHz band from Brett, PJ2BR on the island of Curacao was received by Javi, LU5FF in Argentina. The propagation mode was Trans-Equatorial Propagation (TEP) and the distance was 4853kms.

After it, there was some question about if it was real? Was it a false decode of the Q65 signal? Was there an issue with the software when changing bands from 144 MHz to 432 MHz? Reports of TEP signals on the 432 MHz band are extremely rare and people are right to be cautious.

Now we have a second example of a 432 MHz opening on the 24th of February 2023. This time, we have decodes of signals on both ends as well as visual evidence of a signal in the waterfall display as well as reception of a signal that could be heard.

24th February 2023: Both Brett, PJ2BR and Diego, LW2DAF report that there was a TEP opening on the 432 MHz band on the 24th of Feb 2023. The time was around 00:40 UTC which was about 8-9pm local time on the 23rd of Feb for the parties involved which is around the peak time for evening TEP openings.

On this occasion, there were decodes at both ends and the distance was around 5310kms.

I have some images below so that we have a record of this opening.

The image above is a screenshot from the PSK Reporter website showing the 432 MHz path reported on the site.

This image above is from a screenshot from PJ2BR and shows the left hand side of the WSJT-X software showing reception of LW2DAF with a signal of -18dB. You can see the mode used was Q65-30B. Note that I edited the image to make it smaller vertically to remove the blank area.

This image above is the right hand side of the screenshot. It shows the reception of LW2DAF at -18dB and then PJ2BR sending the report.

Now from Argentina. This image above shows a very weak signal in the waterfall at around 700 Hz.

This image above shows LW2DAF decoding the signal from PJ2BR with a peak of -12dB. This is significant because it was now at a level where the signal might be heard.

Diego, LW2DAF said that he saw and heard the signal on 432 MHz.

Trying TEP on 432MHz, Thanks @pj2br for tried! The path exist, need more stations trying! pic.twitter.com/b6g4JnU1x2

— Diego Alejandro Feil (@LW2DAF) February 24, 2023

This video clip above from LW2DAF on Twitter shows the reception of the signal.

This screenshot from the video shows the Kenwood radio used by LW2DAF on 432.174 MHz.

Equipment: For this TEP test, PJ2BR was using a Kenwood TS2000 with 100-watts from a Mirage amplifier.

The antenna was shown above was a M2 22-element horizontal Yagi.

LW2DAF was using 50-watts into a horizontally polarised 18-element LFA Yagi about 21m above ground level.

Analysis: As Deigo LW2DAF noted, a visual and audible TEP signal on the 432 MHz band has now been verified. It would seem that it is now only a matter of time before someone from Argentina or Brazil completes a 432 MHz contact with someone in the Caribbean using Trans-Equatorial Propagation.

From my understanding of TEP, it's Class II as shown above as an effective duct appears on the Geomagnetic Equator.

At 432 MHz, location, distance and being at right angles to the Geomagnetic Equator are even more important than they are at 432 MHz. As Diego notes, more stations on 432 MHz are needed to try this path at 70cms. It just needs two stations to be in an optimum location and for the conditions to be right.

Link: For other examples of long distance openings on the 70cms band, see my 432 MHz page.

4853km TEP opening at 432 MHz reported from Curacao to Argentina - 5th Feb 2023

Brett, PJ2BR in Curacao in the Caribbean reports that on the 5th of February 2023 (01:18 UTC), his 432 MHz signal were heard by Javi, LU5FF in Argentina by Trans-Equatorial Propagation (TEP). The distance was 4853 kms!

This really is ground breaking news (*). It was only on the 4th of February that I put up a post about what was up to then the only 432 MHz reception report via TEP in South America and that was from 1978. I tagged PJ2BR on Twitter about the post and a few hours later, we have a second 70cms TEP report!

The Green exchange is for 144 MHz while the Yellow is for 432 MHz (*).

Proof of Concept (*)... For this TEP opening on 432 MHz, PJ2BR was using the Q65b weak signal mode. This is significant because it means that modern digital weak signal modes can be used for TEP openings at 70cms. It's not a case of there being too much doppler or spreading of the signal that only CW can be used. This would likely require a much stronger signal for a contact to be made.

For the record, here is a screen grab off the PSK Reporter website before it disappears.

Let's hope that this news will encourage more stations in the Caribbean and in South America to try to make a TEP contact on the 432 MHz.

(*) = Caveat... Someone raised the question if the reports on 432 MHz are genuine? They do after all follow some Q65 reports on 144 MHz and they wonder if it's the software generating these 70cms reports?

It's a bit like conducting a science experiment and we have one data point, not exactly the five-sigma required for a definitive conclusion. What we need are more stations in South America and the Caribbean to test the TEP path on 432 MHz. If there are no more reception reports then it raises some question mark over this new report. If there are more reports then it means this report was probably ok.

Addendum: 6th February 2023... There was another TEP 'reception report' on 432 MHz on the 6th of February 2023. This time it was from WP4KJJ in Puerto Rico to LU9FVS in Argentina.

I believe the stations involved have concerns about the software generating incorrect reports after the band has been changed.

I suspect what is required is the reception of a good old fashioned CW signal to eliminate any software issues.

5100km TEP opening on 432 MHz from Argentina to Venezuela - February 1978

While openings via TEP (Trans-Equatorial Propagation) on the 144 MHz band seem to be relatively common in South America, it's a different story on the higher frequencies.

While there have been verified TEP openings at 432 MHz in Africa in the past, any reports of TEP openings on the 70cms band seem to be extremely rare.

Back on the 13th of February 1978, YV5ZZ in Venezuela reported hearing LU3AAT in Argentina on '432.1 MHz'. The distance was approximately 5,100kms.

I'm not sure of the exact locations of either stations but Buenos Aires to Caracas is about 5,100kms and seems to be the right distance.

I found two accounts about this remarkable reception reports.

Article 1) The first one appeared in the Amateur Communications column, Electronics Today International from May 1978.

"Evening-type TEP extended to 432 MHz?

Recent record-breakng contacts on the 144 MHz band apparently supported by evening-type (or Class II) trans-equatorial propagation between Australia and Japan, Puerto Rico and South America, have been hot news in amateur circles amongst those who are keen on VHF/UHF DX.

However, no sooner was the upper frequency limit of Class II TEP extended to 144 MHz, previously established as being in the 100 MHz region, than evidence of the possible extension of this ionospheric propagation mode even higher in frequency - to 432 MHz - has come to hand.

YV5ZZ, located in Venezuala, is reported to have heard an Argentinian station, LU3AAT on 432.1 MHz in February during an opening when Argentinian stations were heard working Caribbean stations and stations in the northern countries of South America.

However, two way contact was not established, but this seems only a matter of time."

Article 2) The second one appeared in an article titled 'A Newly Discovered Mode of VHF Propagation [1978]' from the QST magazine dated October 1978.

"On February 13, 1978, YV5ZZ heard weak but identifiable signals from LU3AAT, on 432.1 MHz. Two-meter and 432 propagation far exceeds the capability of the TE mode YV5ZZ was using his satellite antenna system, which is steerable in azimuth and elevation. In the direction of LU3AAT, his horizon is obstructed by a range of mountains. The lowest elevation angle which allows for clearance of the mountain range is 8 degrees. 

On February 16, 1978, YV6ASU heard LU3AAT on 432 MHz, with his antenna at about the same angle of elevation. On yet another occasion, KV4FZ heard LU3AAT on 145.1 MHz. He reported that a peak in signal strength occurred when the antenna elevation angle was 8-10 degrees. This geometry suggests that single-hop F-layer reflection isn’t involved. The angle also seems high for the tilt associated with TE."

Analysis... In preparing this post, I did a search for the first 432 MHz contact with Trans-Equatorial Propagation (TEP) in South America and much to my surprise, I couldn't find anything. Despite the 1978 article saying that a 70cms contact would only be a 'matter of time', it looks as if it never happened and has yet to happen.

This raises the point that I have made in previous TEP related posts... Is there anyone in South America trying to make TEP contacts on 432 MHz??

I see many reports of TEP contacts at 144 MHz made by LU, PY, CX & ZP stations in South America and that's fine. But I think radio amateurs should also be experimenting to see what is possible, to try something new and to push the limits.

The chart about shows the progression of sunspot numbers since 1965. In 1978, the levels aren't that much higher than they are now in the Spring of 2023 and 1978 was also about two years before the peak of solar cycle 21.

Doppler... TEP propagation is well known for it's distortion of the signal due to some spreading. The higher the frequency, the higher the distortion.

I'm assuming that the distortion at 432 MHz will mean that modes like FT8, FT4 and Q65b cannot be used? But is that a correct assumption?

If nothing else, the use of modern weak signal modes will allow a weak signal to be seen on a screen even if it can't be decoded. A sign that a CW contact might be possible if only the signal was a bit stronger.

In conclusion... If anyone has any information about previous TEP contacts on 432 MHz from South America then  please let me know. If not, perhaps someone would like to try for the first 432 MHz TEP contact from South America?

Acknowledgement... Thanks to Carlos, LU7MC for sending on the Electronics Today International article. If your first language is Spanish and you're reading this post via Google Translate then send your information to LU7FC if it's easier.

Link...
1) For examples of TEP contacts on 2m, see my 144 MHz page.
2) For examples of other long distance contacts on 70cms, see my 432 MHz page.