❌

Normal view

There are new articles available, click to refresh the page.
Before yesterdayMain stream

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


Β 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


TheΒ Trans-Equatorial PropagationΒ (TEP) openings from Namibia to Europe on theΒ 144 MHzΒ 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 HzΒ  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) SeeΒ my 144 MHz pageΒ for more examples of long distance contacts.

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


TheΒ Trans-Equatorial PropagationΒ (TEP) openings from Namibia to Europe on theΒ 144 MHzΒ 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.Β  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) SeeΒ my 144 MHz pageΒ 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 IZ8EDJΒ  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

Β 

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.Β 

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.

❌
❌