Interference during the recent Namibia to Europe TEP tests - Apr 2024

There have been many remarkable Trans-Equatorial Propagation (TEP) openings recently on the 144 MHz band from Namibia to Europe. This all started off when a group was established on WhatsApp where individuals in Europe and Africa exchanged messages to try and co-ordinate the tests.

The problem with evening type TEP is that the signals are often very distorted at 144 MHz and modes like FT8 often don't work. To address this issue, the group decided to try the Q65 mode which has been a huge success. They picked the frequency of 144.190 MHz to carry out these TEP tests.

The choice of frequency is important because it was just a frequency chosen to carry out TEP tests, it's NOT the official Q65 frequency.

The problem now is that as news of the TEP contacts has spread, European stations are starting to work each other on 144.190 MHz with Q65. The problem here is that they are blocking the weak TEP signals from Africa.

The organisers of the TEP tests moved the frequency to 144.192 MHz to avoid the interference from EU to EU contacts but the central message is that the area around 144.190 MHz should be left clear for only TEP contacts from Europe to Africa.

In terms of sequence, Africa always transmits first, Europe always second.

Guest Post: Example of Lightning Scatter at 144 MHz ...by Kadri, TA1D

In a follow up to my recent post about lightning scatter at 1296 MHz, Kadri TA1D got in touch to say that he saw another example at 144 MHz. He wrote a post about it on his blog in Turkish and that is linked from the bottom of this post. 

He has kindly given me permission to publish a version in English here. I'm using Google Translate for most of this post with a few corrections so a few errors may creep in.

John, EI7GL

***

Contribution of lightning to Radio Communications at 144 MHz ...by TA1D

Towards the end of summer 2021, I was operating from my summer QTH station in the North Aegean in Turkey / Turkiye. It was raining with lightning one day when I was communicating with Meteor Scatter on 144 MHz and I decided to check if the SV2JL/B beacon station in Greece on 144.450 MHz could be heard during the hours when lightning was concentrated in the middle of the Aegean Sea.

I turned my antenna to the west and started listening on 144.450 MHz. At that time, the sound of the CW beacon could be very faintly heard with some fading (QSB). Sometimes it became  unreadable and rose again, but overall, the signal level was very poor.

While I was listening, I also had the computer monitoring with the MSK144 mode and sometimes, the morse signal appeared clearly on the screen as short and long lines.

I noticed that I was also hearing the static crashes from the lightning and these can be seen on the screen shot above.

I noticed that I could hear the radio signals of SV2JL/B very faintly during each lightning strike. When the static crash was at a red level, the morse signals became loudly audible before dropping back down to a lower level.

I realised that I had witnessed an interesting physical event and it was possible due to my position and situation.

Is it of any use to radio amateurs? Yes, it can be useful. We can make use of meteor scatter with the MSK and FSK modes to make contacts using short pings and bursts. We could also make use of the short scatter signals from lightning strikes.

Thanks to lightning, we are listening and sending like meteor scatter communications. Lightning strikes at the appropriate angle between the two stations during our meteor scatter style QSOs may help us communicate.

In conclusion; This physical phenomenon that I have noticed and determined can be effective in amateur radio communication.

There may be articles written by people who witnessed similar events on different web pages, but I have not come across them yet.

Meteorite: Pieces of Stone, Soil, mineral and ice floating or orbiting in space.

MS: Meteor Scatter, bouncing off meteor trails, reflection.
MSK and FSK: Digital communication mode
Beacon: Radio Beacon, Robot station that sends Morse or digital signals at certain intervals.
CW: Morse signal, carrier wave
RF: Radio Frequency
SV2JL/B: Robot Beacon station installed in Greece
APS: Airplane Scatter: Reflection and scattering from the aircraft surface.

TA1D Kadri K.Mehmet Başak

Links...

1) The full original article is on the TA1D website... http://ta1d.com/?p=226

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.

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.

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.

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.

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.

Day 7: TEP opening on 144 MHz from Namibia to Europe - 6th Apr 2024

The Trans-Equatorial Propagation (TEP) openings from Namibia to Europe on the 144 MHz continued on the 6th of April 2024 and again to the same geographical area. The reports from the PSK Reporter website are shown above.

SV8ALQ in Greece reports... "Today was a very good opening between Greece and Namibia. I made contact with V51WW mode Q65b at 144.190 at 18.47. Best I heard him was -12dB"

Links...

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

Day 6: TEP opening on 144 MHz from Namibia to Europe - 5th Apr 2024

 

The Trans-Equatorial Propagation (TEP) openings from Namibia to Europe on the 144 MHz continued on the 5th of April 2024 and again to the same geographical area. The reports from the PSK Reporter website are shown above.

There was an earlier report in the day at 12:32 UTC from Albania but this was almost certainly an error with someone reporting the 6m decodes as 2m.

DX-Cluster spots...
IT9GSF 144190.0 V51WW 20:13 05 Apr LONG TEP 18:26 till 19:35 Namibia
IK7EOT 144190.0 V51WW 18:50 05 Apr Q65B Namibia
IZ8EDJ 144290.0 V51WW 18:48 05 Apr JN70-TEP-JH81 Namibia
9H1TX 144191.2 V51WW 18:46 05 Apr JM75FU<TEP>JH81OC Q65 tnx agai Namibia

Links...

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

Day 5: TEP opening on 144 MHz from Namibia to Europe - 4th Apr 2024

The Trans-Equatorial Propagation (TEP) openings from Namibia to Europe on the 144 MHz continued on the 4th of April 2024 but to the same geographical area. The reports from the PSK Reporter website are shown above.

Alex, SV1NZX reports... "V51WW is currently the only station being heard from Africa but working IK7UXY, SV2DCD, SV8PEX, IT9GSF, IK7EZW and 9H1PA, amongst others. Same geography and area but slightly stronger signals tonight, initially

Interestingly, also, ZS4TX was tx-ing North too, although nothing was received and FR5DN was beaming to A6/TA/9K where stations are located. No luck as of yet but conditions are not ideal, to be fair."

From SV2DVD

Spots from the DX-Cluster...

IT9GSF 144190.0 V51WW 20:56 04 Apr JM67-TEP-JH81 6314Km @18:38 Namibia
IK7EOT 144190.0 V51WW 19:01 04 Apr Q65B -21 Namibia
SV8PEX 144190.0 V51WW 18:42 04 Apr Q65B first -13 nice via TEP Namibia
IK7EZN 144190.0 V51WW 18:39 04 Apr TEP 6550 KM Namibia
IV3KKW 144190.0 V51WW 18:38 04 Apr Q65 wkg Med Namibia

Links...

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

TEP opening on 144 MHz band from Japan to Australia - 3rd Apr 2024

In addition to the recent Trans-Equatorial Propagation (TEP) openings at 144 MHz from Namibia to Europe, there have also been similar openings from the far south of Japan to the north of Australia.

The map above shows the paths reported on the PSK Reporter website for the 3rd of April 2024.

In fact, there have been almost daily openings reported from at last the start of March. Here are a few of the spots from the DX-Cluster...

JA6DJS 144460 VK8VTX 11:51 02 Apr 24 FT8 CQ Australia
JA6DJS 144460 VK8AW 12:26 01 Apr 24 FT8 CQ Australia
JA6DJS 144150 VK8ZMX 12:55 31 Mar 24 SSB TNX! Australia
JA6DJS 144460 VK8AW 12:49 22 Mar 24 FT8 -03dB Australia
JA6DJS 144460 VK8VTX 11:39 20 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8VTX 12:59 19 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8VTX 1:17 18 Mar 24 FT8 CQ Australia
JA6DJS 144150 VK8AW 12:34 17 Mar 24 SSB Australia
JA6DJS 144150 VK8DNT 13:04 16 Mar 24 SB TNX QSO! Australia
JA6DJS 144460 VK8VTX 12:01 12 Mar 24 FT8 CQ -10dB Australia
JA6DJS 144460 VK8VTX 12:13 11 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8VTX 12:09 10 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8AW 11:27 08 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8NAH 11:27 08 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8AW 11:41 06 Mar 24 FT8 Australia
JA6DJS 144460 VK8AW 12:04 05 Mar 24 FT8 TNX QSO! Australia
JA6DJS 144460 VK8AW 12:21 04 Mar 24 FT8 TNX QSO! Australia

Most of the signals are FT8 with no mention of the Q65 mode. There have been a few SSB contacts as well.

The distances are in the region of 4,900kms and the southern end of the path seems to be determined by the fact that most radio amateurs in that region are clustered around the city of Darwin.

There seems to be very little activity from Japan despite the sea path to the south with possible tropo extensions. I wonder if VHF stations in Japan are aware of these TEP openings to the south?

Links...

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

Day 4: TEP opening on 144 MHz from Namibia to Europe - 3rd Apr 2024

Day 4: This was the 4th day in a row that there was a Trans-Equatorial Propagation (TEP) opening on 144 MHz from Namibia to Europe. It's very likely that this path was open for most of March as well but there was no-one testing the path.

The paths from the PSK Reporter website are shown above and this time, the signals reached further north in Italy.

Here are some spots from the DX Cluster...

SV2DCD 144190.0 V51WW 18:35 03 Apr -15db Q65B via TEP tnx Namibia
SV8PEX 144190.0 V51WW 18:33 03 Apr JH81 Q65B only RX tonight, wea Namibia

It's interesting to note how the maximum spread of the TEP footprint at the northern end is about 750kms. The TEP signal needs to cross the Geomagnetic Equator close to 90 degrees and the question is how far from 90 degrees can the path be before there is no propagation at 144 MHz?

Alex, SV1NZX notes that he has heard no signals from V51WW with a 9-element yagi at his location near Athens (KM17) which suggests he is too far to the east. He writes... "SV2DCD was using a 4 x 17 array to hear / work EME-level signals from V51WW. On the other hand, SV8PEX and IZ8/IT9/9H have had the lion's share of signal strength, hence the SSB QSO's."

I know the TEP posts can be a bit repetitive but I think it's important to keep a record of the information and maps. This is the most important VHF news in Europe at the moment.

Links...

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

New 144 MHz TEP beacon in South Africa - April 2024

Bernie, ZS4TX reports that a new 144 MHz beacon has started in South Africa to investigate the possibility of Trans-Equatorial Propagation (TEP) to the Mediterranean and Europe.

Bernie, ZS4TX writes... "New ZS Beacon for 2M TEP tests in April from KG33XU. ZS6RVC has started a 25W beacon on 2M with a 14 element yagi 20M high on a mountain site with a clear shot to EU.

The frequencies to listen on according to my IC910H is as follows:
144.449.2 CW 600Hz tone
144.448.6 USB 600Hz tone

Please monitor this frequency as well between 16Z and 21Z and send any reports to me. It sends ZS6RVC /B KG33XU in CW ~ 12 WPM"

Analysis... As the 144 MHz signals are likely to cross the Geomagnetic Equator at right angles (90 deg), the most likely area for reception of this beacon is probably going to be the eastern half of the Mediterranean.

Back in 1981, there was a TEP opening on 144 MHz from this part of South Africa to the Athens area in Greece so it may be possible again.

Links...

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

Day 3: SSB contacts made on 144 MHz during TEP opening from Namibia to Europe - 2nd Apr 2024

The most significant VHF amateur radio news at the moment in Europe is without doubt the TEP (Trans-Equatorial Propagation) openings on 144 MHz to Namibia. See 1st April.

Tuesday the 2nd of April 2024 was Day 3 of the recent opening and the reports on the PSK reporter site are shown above. The paths are similar to the previous two days except the path to SV2DCD is a new one.

The screen grab below is from SV2DCD which shows reception of V51WW. As far as I know, a two way contact was not completed.

What made this day special though was that some contacts were made on SSB! Tom, SV8PEX posted this on the DX Cluster... SV8PEX 144150 V51WW 18:33 02 Apr 24 JH81 SSB 52 52 many thanks!!!

Alex, SV1NZX reports that V51WW made four SSB contacts on 144.150 MHz with IK7UXW, IK7JNM, IK7LMX and SV8PEX.

Video... A video clip from V51WW can be found on this link ... https://twitter.com/i/status/1775255255539945703

Note the distortion on the voice. I presume that was the SSB contact with Tom, SV8PEX.

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.

Commercial 144 MHz Cavity Filter - PE1RKI

I was recently looking at the website of Bert Modderman, PE1RKI in the Netherlands and I noticed that he is selling cavity filters for the 144 MHz band.

A cavity filter is essentially a hollow tube with tuning rods inside and can usually handle much higher powers than say a lot of the smaller band pass filters on the market which use inductors and capacitors.

The specs for this filter are that it has a 0.2dB insertion loss and it can handle up to 1-kilowatt of RF. It comes supplied with N-type connectors.

I have edited the diagram of the frequency response for the filter to make it clearer.

Signals on the marine band around 156 MHz are down about 18dB. Signals in the VHF air band (~120-130 MHz) are down about 10 - 12 dB.

If we were to extrapolate the shape of the graph down to say FM broadcast band on 88 to 108 MHz then the signals are probably down about 15 - 20 dB.

PE1RKI also makes a version for the 432 MHz band.

More information about the filters can be found HERE

Disclaimer: Just to be clear, this isn't an advertisement. I wasn't paid for this post or I wasn't sent the product for review. I just think this is something VHF operators will be interested in.

PE1RKI also sells a number of amplifiers, filters and antennas for the microwave bands. We all know you can buy lots of gear from websites the likes of Ali Express and eBay but a lot of it is rubbish. It's worth considering supporting small manufacturers and shops in Europe.

3275km opening on 144 MHz between Madeira Islands and Denmark - 17th Dec 2023

There has been some remarkable tropo conditions in Europe over the last few days with some stations completing contacts on the 144 MHz band in excess of 2000kms. 

One of the longest contacts was that shown above... an amazing 3,275 km contact using FT8 between Thomas, OV3T in Denmark and Stefan, CT9/OM3RG on the Madeira Islands. See report from Stafan at the bottom of the post. Thomas reports using 700-800w into a 2 x 11-element Yagi on a 18m tower. 

As can be seen from the map above, it is mostly a sea path but it does have to cross some land.

Bernd, DF2ZC in Germany also reports working CT9/OM3RG and the distance for this 2m contact was 2,818 kms. Bernd reports using EME power to 4 x 18-element M2 Yagi. Bernd also reports that the path had to cross over 1800m high mountains in the north-west of Spain. 

Propagation Mode???... The long path over the sea would suggest it was one of the marine ducts that we have seen in the past resulting in really long distance contacts. The obstructed path however from DF2ZC to the Madeira Islands would suggest an elevated duct. Was it a combination of a marine duct near the surface and an elevated duct?

The tropo forecast by Pascal, F5LEN certainly suggests a good sea path for some areas.

I think some people will have their own ideas but I don't think anyone can be certain on this one.

Update: See bottom of post for another propagation map.

Link... For examples of other long distance contacts on the 2m band, see my 144 MHz page.

Addendum 1: Thanks to Stefan, CT9/OM3RG for sending on this additional information.

Stefan reports that he was using 100-watts from an ICOM IC-9700 into 2 x 9-element LFA Yagi.

He reports that he worked as many stations as he could with his 100-watts. He heard lots of other stations from Germany (DL), Belgium (ON) and Netherlands (PA) but they couldn't hear him.

This is a list of stations that Stefan worked on the 17th & 18th of December 2023. 3000km+ stations in red, 2500km+ in orange. CW in bold.

20231217 7:02 F6DBI IN88IJ FT8 2085

20231217 9:36 MW0AXA IO81FQ FT8 2371

20231217 9:37 GW7SMV IO81LN FT8 2378

20231217 9:38 G4CBW IO83UB FT8 2546

20231217 9:40 EI9KP IO54MB FT8 2450

20231217 9:44 G8JLY IO82WG FT8 2480 

20231217 9:45 G0PQO IO92UA FT8 2365

20231217 9:46 M0PNN IO82TS FT8 2516

20231217 9:49 G4FUF JO01GN FT8 2530

20231217 10:12 F6EGD IN88HR FT8 2110

20231217 10:14 G4EZP JO01GN FT8 2530

20231217 10:25 G8HGN JO01FO FT8 2530

20231217 10:28 EI8KN IO62IE FT8 2296

20231217 10:30 F6HRO IN88JQ FT8 2114

20231217 10:32 G7GXK IO90IS FT8 2378

20231217 10:40 G8TTI IO81WM FT8 2408

20231217 10:42 2E1EMK IO91BI FT8 2404

20231217 10:47 G4BNM IO93EV FT8 2644

20231217 12:04 G4ELW IO81MC FT8 2337

20231217 18:21 G4ZFJ JO01HO FT8 2538

20231217 18:22 CT7AUS IM58HT FT8 968

20231217 18:24 G0LGS IO81WV FT8 2444

20231217 18:25 G8GON IO80HP FT8 2281

20231217 18:27 G4KWQ IO92AQ FT8 2523

20231217 18:28 M0BUL IO82NG FT8 2450

20231217 18:29 G4NBS JO02AF FT8 2564

20231217 18:30 M6JAY IO90HV FT8 2387

20231217 18:30 G7RAU IO90IR FT8 2377

20231217 18:31 G4DCV IO91OF FT8 2442

20231217 18:31 G0BIX JO01CI FT8 2498

20231217 18:32 G0ODR JO02OP FT8 2651

20231217 18:32 G0JDL JO02SI FT8 2642

20231217 18:33 PA4ZP JO21RK FT8 2766

20231217 18:38 G1OJS IO90JU FT8 2391

20231217 18:43 G0LTG IO81RF FT8 2367

20231217 18:44 G6HIE JO00DW FT8 2467

20231217 18:47 PA3BIY JO22HB FT8 2768

20231217 19:22 G3TKF IO81SJ FT8 2386

20231217 19:24 M0CFV IO91UM FT8 2489

20231217 19:25 G4ZTR JO01KW FT8 2577

20231217 19:28 G7WIR JO01BJ FT8 2497

20231217 19:28 G3XDY JO02OB FT8 2602 

20231217 19:29 G3XDY JO02OB FT8 2602

20231217 19:31 F6EAS IN98LV FT8 2235

20231217 19:32 G4GFI IO91VH FT8 2475

20231217 19:34 OV3T JO46CM FT8 3275

20231217 20:09 GW4SHF IO82HP FT8 2466

20231217 20:11 G4RGK IO91ON FT8 2471

20231217 20:13 PA2M JO21IP FT8 2741

20231217 20:16 G4AEP IO91NJ FT8 2453

20231217 20:19 G4KPZ IO92WK FT8 2575

20231217 20:21 G0JJG JO02ME FT8 2605

20231217 21:42 PA2CHR JO32DB FT8 2854

20231217 21:48 DG6JF/P JO33QN FT8 3017

20231217 21:50 PA3DZL JO21LS FT8 2763

20231217 22:08 G4DHF IO92UU FT8 2605

20231217 22:10 PA3BIY JO22HB FT8 2768

20231217 22:20 G0LTG IO81RF CW 2367

20231217 22:21 G4DHF IO92UU CW 2605

20231217 22:27 G0LTG IO81RF CW 2367

20231217 22:42 ON4KHG JO10XO FT8 2626

20231217 23:21 G0GMB IO92NB FT8 2511

20231218 6:37 F6KHM IN78RJ FT8 2028

20231218 6:39 G4FUF JO01GN FT8 2530

20231218 6:46 F5DQK JN18GR FT8 2413

20231218 6:50 G4EZP JO01GN FT8 2530

20231218 6:51 F6GNR IN97FD FT8 2069

20231218 6:53 EA1M IN53TI FT8 1399

20231218 6:55 G4RRA IO80BS FT8 2272

20231218 7:24 G4MKF IO91HJ FT8 2431

20231218 7:37 ON4KHG JO10XO FT8 2626

20231218 7:46 ON4KHG JO10XO FT4 2626

20231218 7:55 G3XDY JO02OB FT4 2602

20231218 8:36 M0VXX IO90 FT8 

20231218 8:40 EA7JCR IM67WK FT8 1129

20231218 8:47 G3WZT IO90UX FT8 2443

20231218 8:49 G4DDK JO02PA FT8 2603

20231218 8:52 M0CKM IO90QT FT8 2414

20231218 8:54 G4FSG JO02PC FT8 2610

20231218 8:55 EA1YV IN52OC FT8 1268

20231218 8:59 G3WZT IO90UX CW 2443

20231218 9:02 M0CKM IO90QT CW 2414

20231218 9:10 EA1DFP IN53XI FT8 1416

20231218 9:12 G6HIE JO00DW FT8 2467

20231218 9:20 EA1CCM IN52QG FT8 1291

20231218 9:21 G3ZSS IO90NU FT8 2406

20231218 9:23 G3SJX IO91LC FT8 2420

20231218 9:44 DF7KF JO30GU FT8 2785

20231218 9:45 OQ4U JO20KV FT8 2696

20231218 10:01 PA1BVM JO21RO FT8 2778

20231218 10:15 PA3DOL JO22MT FT8 2845

20231218 10:30 PA3DOL JO22MT FT8 2845

20231218 10:35 G0JJG JO02ME CW 2605

20231218 10:47 G4CKS IO91VL FT8 2489

20231218 10:59 DF2ZC JO30RN FT8 2818

20231218 11:45 DL8YE JO32TC Q65A 2929

20231218 13:11 G4HSK JO01FS FT8 2544

20231218 13:18 G4BWP JO02FH FT8 2590

20231218 13:19 G0LQI IO80SP FT8 2319

20231218 13:23 PA0CAB JO22DA FT8 2748

20231218 13:34 PA3DOL JO22MT FT8 2845

20231218 15:38 DL1YDI JO42FA Q65A 2969

20231218 16:02 DM1CG JO30GU Q65A 2785

20231218 16:26 DM1AC JO30IV Q65A 2797

20231218 18:46 PA3BIY JO22HB FT8 2768

20231218 18:48 PA3FYC JO31AF FT8 2783

20231218 19:11 PA5Y JO21VO Q65A 2795

20231218 19:39 DL5EBS JO31NH Q65A 2848

20231218 19:54 ON4CLQ JO11SE FT8 2647

20231218 20:09 F5RZC JO10JG FT8 2539

20231218 20:50 ON4MU/P JO20ET FT8 2663

20231218 21:01 DL5EBS JO31NH FT8 2848

Addendum 2: PA3AUC supplies the following chart which suggests that the opening was due to an elevated duct at 500-750m.

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.

Limerick 2m repeater EI2REG back on air

The Limerick repeater on 145.725 MHz is one of the oldest FM repeaters in Ireland and originally came on air back in the 1980's. It went off air back in 2018 when there were access issues with the site on Tountinna to the north-east of Limerick City.

It is now back on air from a new site which is 40kms to the south-west of Limerick city.

Info from Limerick Clare Radio Club... "The  Limerick Clare Radio Club 2m Repeater back on Air After a five year silence, the Limerick Clare Radio Club 2 metre repeater returned to air on Thursday June 2nd. The new site is located at Rooskagh East near Ardagh in West Limerick and the club is extremely to Ray Elgy EI3DQB for allowing the club to relocate the repeater to his QTH. ComReg have issued the callsign EI2REG for the new location. The frequency remains the same as it was for Tountinna. The Repeater Channel is R5. Transmission is on 145.725 MHz and it receives on 145.125 MHz. Modes are FM and C4FM. Reception reports would be appreciated by the club and can be sent to ei4lrcclub @ gmail DOT com"

The new repeater is on an elevated site which should give good local coverage of County Limerick. It is however badly screened by local hills to the west and south. Hills and mountains about 60kms away screen it from much of the rest of Ireland.

This repeater is 85kms from my elevated location near Cork City and when I listened, it was very weak and buried in the noise.

It's possible that this repeater may be heard in the western part of the UK under lift conditions but it's likely that conditions would need to be very good as opposed to a slight enhancement.