Is there a bogus ZD7GWM beacon operating on 144 MHz in the south of France???

Back in the middle of March 2021, I reported in a previous blog post how F0FYF in the east of France had heard a beacon on 144 MHz that was using the same callsign as the ZD7GWM beacon on St Helena in the South Atlantic.

After listening to various recordings, I was able to confirm that the signal heard by F0FYF was different from the real one. 

Now, there is a report that the beacon has been heard by someone else in France but on a completely different beam heading.

Someone left a comment on the blog of Jeff, F0FYF to say that they had heard the bogus ZD7 beacon on 144.475 MHz as well! This person said that he was in the south of Perpignan and that the 'beacon' was on a beam heading of 70 degrees from his location. He was using a 7-element Yagi on a 9-metre mast.

F0FYF originally said that he had heard the beacon on a beam heading of 200 degrees. I plotted out these two beam headings and they intersect near Marseilles.

They also said that the beacon is often on air for 90 minutes to 2 hours at a time on a regular basis. 

Is it located somewhere inside the circle above?? It would be interesting for some local French radio amateurs to have a listen. Is there an online SDR with 2m in the area?

Links...

1) My original post

2) Blog post on F0FYF blog with comments (in French)

144 MHz beacon on St Helena heard 7000kms away in France by TEP - is it real?

Back in February of 2021, I had a post up about the new 144 MHz on St Helena Island in the South Atlantic. On the 3rd of March, I reported that the beacon had been heard over 3000kms away in South Africa.

Now just two days later, F0FYF in France claims to have heard it.

* * *

13th March 2021... Note that the recording from France does not match the recordings from South Africa.

For updates, scroll down to the end of this post.

* * *

The path is almost 7000 kms! If confirmed then it looks likely that the propagation mode was via Trans-Equatorial Propagation (TEP) from St Helena Island to the north coast of Africa and then via tropo across the Mediterranean.

An audio recording from F0FYF can be heard below...

Check out the audio of the beacon here...

F0FYF · Beacon2

The D7GWM/B in CW can be clearly heard. The beacons locator is IH74DB.

In a post on his website, F0FYF wrote..."The other day, I was touring the audible beacons from my house on a VHF. The spread appeared to be good especially to the south / southwest. The Pic Neulos arrived in excellent conditions on 144.4765 Mhz, even CN8LI was audible at times, with great difficulty but the LNA was there to help. I used for these receptions, a stack of 2 x 9 elements at 7m from the ground on a temporary pylon (the neighbors cannot stand the sight of metal and their nausea and headaches happen, as if by chance, as soon as I mount my pylon, even not connected ^^, in short ..)

During my little tour, I stopped on 144.47535 Mhz after hearing some very delicate pieces of walrus to decode. The antennas pointed at 200 ° and as soon as I turned more than 5 ° in one direction or the other, the signal disappeared. Surely a reflection on a massif. 200 ° de chez moi passes just between the Semnoz massif and Le Mont du Chat. I am still at 700m with a fairly clear view from my home. I started the recording and I was able to recover some bridles but I couldn't get it correctly. Another OM that I had warned could hear absolutely nothing from his position. I went around MMMonVHF , my reference for beacons, to try to know its origin but I haven't found anything yet. The beacon disappeared around 11 p.m."

Some points here...

1) The ZD7GWM beacon is on 144.475 MHz so the frequency is correct.

2) The beam heading for F0FYF to St Helena is 193 degrees which is close to the 200 degree beam heading that F0FYF used.

3) The beacon was heard between 19:45 and 22:50. The recording was taken at 20:47. The time is in the late evening which matches some TEP propagation.

4) There are recent reports of 144 TEP on the DX cluster from the Caribbean to Brazil & Argentina. This suggests that it might be possible for the ZD7 beacon to be heard in Europe.

This is the second recording...

F0FYF · Beacon

This one has 'E W M T'  & '7 E' in cw so I am not sure what that is??? Someone suggested that it might 'G W M /' with the start and finish cut off. If it is, the level of fading seems very sharp and severe.

It would be great if more people in southern Europe could listen for this beacon on 145.475 MHz. If it is TEP as expected then it should be heard again in the late evening.

Like any good science experiment, we need more data points!

Link...

1) F0FYF website

* * *

Update 1 of 2... 10th March 2021: There seems to be a difference between what the beacon really sounds like in South Africa and what was heard in France. This casts some doubt as to whether it was really the St Helena beacon. More to follow...

* * *

I was sent recordings of what the beacon sounded like when it was on the bench under test and what it sounded like as recorded by V51DK in Namibia.

I fed these audio clips and the one from F0FYF into the Spectrum Lab audio programme and this is what I found.

The three recordings are shown above. The dotted vertical line is a 2-second mark.

1) Callsign Length: The recording by ZS1NAZ when the beacon was on the bench is shown in the centre and this is essentially the reference. The callsign 'ZD7GWM/B' in morse as recorded by ZS1NAZ is 9 seconds long. The callsign as recorded by V51DK in Namibia over a 2250km path is also 9 seconds long. The callsign recorded by F0FYF is 10 seconds long.

2) Dash Length: If the letter 'M' is compared above, there is an obvious difference between the dash lengths. I measured the dot length from the ZS1NAZ recording to be roughly 220 milliseconds (mS), the dash length from the F0FYF recording was roughly 330 mS.

3) Dot Length: The dots in the ZS1NAZ recording are quite short. I measured them to be be roughly 65 mS. I measured the dots in the F0FYF recording to be roughly 130 mS.

4) Character Spacing: If you examine the F0FYF recording, the space between the letter 'M' and the character '/' is about equal to the length of a dash. In the ZS1NAZ recording, this is clearly different. 

I had wondered perhaps if the F0FYF recording was somehow changed to make it clearer, a bit like playing something at 80% speed to make it clearer. If this 10 second recording was reduced down to 9 seconds then the dashes and dots would get shorter as well. However, that wouldn't change the fact that spacing between characters seems longer in the ZS1NAZ recording.

I was sent recordings of what the beacon sounded like when it was on the bench under test and what it sounded like as recorded by V51DK in Namibia.

In conclusion, the signals as displayed above from the F0FYF and ZS1NAZ look different. To the ear, they sound different. The F0FYF recording as more of a T9 clean tone where as the ZS1NAZ recording sounding very different with the morse sounding more abrupt. As someone said to me..."The keying on this recording has a staccato nature".

The F0FYF reception recording was described to me as being probably a genuine reception of a non-genuine signal.

What really needs to happen now is for stations in countries like Spain, Portugal and the south of France to take their radios off the 2m FT8 frequency and listen for the ZD7GWM beacon on 144.475 MHz late in the evening. There are reports of 2m TEP in South America at the moment so there is no reason why it shouldn't be happening on this side of the Atlantic.

* * *

Update 2 of 2... 13th March 2021: Jeff, F0FYF has very kindly uploaded the full recording of what he heard. The full recording is nearly 2 hours long.

* * *

See below...

144 MHz beacon on St Helena heard in Namibia over 2250km sea path

Back in February of 2021, I had a post up about the new 144 MHz on St Helena Island in the South Atlantic. On the 3rd of March, I reported that the beacon had been heard over 3000kms away in South Africa.

On the 9th of March 2021, the 144 MHz beacon was heard by David, V51DK on the west coast of Namibia over a 2253 km sea path.

V51DK who is located in the city of Swakopund has a very modest station and was just using a Diamond X200 vertical antenna at just 6-metres above ground level. 

As the tropo forecast from F5LEN shows below, there were excellent conditions between St Helena and Namibia.

This form of maritime ducting is a regular occurrence is this part of the South Atlantic Ocean.

New 144 MHz beacon on St Helena Island heard over 3000kms away in South Africa - 1st March 2021

Back in February of 2021, I had a post up about the new 144 MHz on St Helena Island in the South Atlantic. Now we have the first reception report!

On the 1st of March 2021, Charles ZS1CF in Cape Town heard the ZD7GWM beacon on St Helena Island over a distance of approximately 3145 kms. The beacon operates on 144.475 MHz with 25 watts on CW into a vertical antenna.

The tropo prediction map above from Pascal, F5LEN shows path and it is believed that the propagation mode was via a maritime duct just above the ocean.

This marine path from South Africa to St Helena is a relatively common occurrence and successful contacts have been made on 2m and 70cms in the last few years. It is hoped that the new beacon will give a better picture of just how often this 3000km+ path opens and encourage others to have a listen as well.

As outlined in the original beacon post, there may be a possibility of a 144 MHz trans-Atlantic path to Brazil or via TEP to Europe.

Link...

1) Update on the new 144 MHz beacon on St Helena Island (ZD7) - Feb 16th 2021

Update on the new 144 MHz beacon on St Helena Island (ZD7)

A few days ago, I had a post about the new proposed 2m beacon for St Helena Island. Dee, ZR1DEE has very kindly sent on some additional information.

Garry, ZD7GWM is the beacon keeper and recently took delivery of  a Motorola GM340 FM radio, power supply, cables and a Diamond X700H antenna.

As of the 4th of February, the antenna still needs to be installed and then the beacon will be turned on.

More info from Dee.....  

Gary will select the beacon frequency from a list of 4 pre programmed frequencies (Channel 1: 144.475 Channel 2: 144.325 Channel 3: 144.375 Channel 4: 144.385 ) to suit .
 
Now we wait for the Diamond antenna to be erected and BEACON SWITCHED ON

* * *

Update 16th Feb 2021: Photos of the new antenna at the bottom of this post.

* * *
 
The keyer circuit is a 8 pin PIC12F675 chip fed to the input of the Motorola  GM340 FM radio

Additional information about the beacon...
Call sign of the beacon  ZD7GWM
QRG – 144.475 frequency
Grid locator IH74DB
QTH LONGWOOD ISLAND OF ST HELENA
Antenna type DIAMOND X700H
Height above sea level  545M
Height above ground  10M
Antenna direction OMNI-DIRECTIONAL
Horizontal or Vertical  VERTICAL
Power output  20 W
Keying – mode CW
Machine Generated Mode if applicable
GPS coordinated  S 15⁰ 56’ 54.68  W005⁰ 41’ 02.34 (-15.9485  -005.6840 )
Beacon status activated soon
Beacon Keeper GARRY MERCURY ZD7GWM

Analysis... Let's have a look at where St Helena is and who is likely to hear this beacon.

3000km plus contact made on 433 MHz from St.Helena to South Africa - 16th Oct 2020

On the 16th of October 2020, there was a remarkable 3000+ km contact made on the 70cms band between South Africa and St.Helena in the South Atlantic.

The contact at 433 MHz was made between Garry, ZD7GWM on St.Helena Island and Tom, ZS1TA in South Africa. The distance was approximately 3136 kms and what was even more amazing was that the contact was made on FM!

The power used for the contact was a modest 35 watts into a vertical antenna. This was a new distance record for a contact between South Africa and St.Helena on the 70cms band.

The mode of propagation was probably a marine duct as shown by this tropo forecast map from Pascal, F5LEN.

This 3000km+ tropo path between South Africa and St.Helena opens up on a reasonably regular basis. Back in November of 2018, there was an opening on 144 MHz as outlined in this previous post.

In June of 2020, the 2m path opened up again and the most recent opening on 2-metres was on the 23rd of September 2020 when ZD7GWM was worked by no fewer than five ZS stations... ZS1TA, ZS3CVB, ZS1CF, ZS3JPY and ZS1FC.

To put these remarkable contacts on 144 MHz and 433 MHz into context, the 3136 km distance is equivalent to the path across the North Atlantic between Newfoundland and Ireland.

Link...

1) Cape Town Amateur Radio Centre: ZS1TA & ZD7GWM Set New 70cm Distance Record - 16 Oct '20

3000km plus contact on 144 MHz from St.Helena to South Africa - 4th June 2020

There are several areas around the world where there are some amazing propagation paths on VHF due to ducts forming over the ocean. One of these seems to happen occasionally in the South Atlantic off the coast of South Africa.

On the 4th of June 2020, there was a successful FT8 contact on 144 MHz between ZS1FC near Cape Town in South Africa and ZD7GWM on St.Helena.

The distance was in the region of 3,040 kms which about the same distance as from Ireland to Newfoundland across the North Atlantic.

Back in November of 2018, ZD7GWM managed to work some ZS3 stations who were further north on the coast and the distance was about 2,700 kms. This new contact with ZS1FC is about 300 kms further.

2700km contact made on 2m from South Africa to St.Helena Island

It was announced on Southgate Amateur Radio News during the week that a contact had been made between South Africa and St.Helena Island on 145 MHz.

"Kobus van der Merwe, ZS3JPY reports that between 19:45 and 21:45 UTC on Wednesday 7 November 2018, a QSO took place on 2 metres between St Helena Island and the West Coast of the Northern Cape. A distance of 2,740 km.

The QSO was on 145,500 MHz FM using a vertically polarised antenna between Garry Mercury, ZD7GWM and Kobus ZS3JPY and Michelle ZS3TO van der Merwe in Kleinzee as well as Cobus van Baalen, ZS3CVB in Port Nolloth.

They did try a QSO on 70 cm, but the signals did not provide for a successful QSO. "

This is a recording of the contact...



Info from Facebook..."From ZS3JPY Kobus: Qso with ZD7GWM with ZS3JPY Kobus, ZS3TO Michelle 2777km and ZS3CVB Cobus 2740km on vhf 145.500 Fm simplex with Vertical antenna 07.11.2018 qso started 21H45 until 23H45 we even tried 70cm and we nearly made a contact but signal just not good enough we will try tomorrow evening. ZS3CVB qso with Gary ZD7GWM on St Helena Island vhf Fm mode and 50w both sides
Gary: ☓520 dual band Diamond antenna;
ZS3CVB: X700H dual band Diamond antenna explorer the vertical antenna and use quality low loss coax Cable.

Me and Cobus were having our evening qso on 145.500 and Gary called in and Cobus ZS3CVB said somebody is breaking in and iam jumping up and down screaming to Michelle: St Helena Island is calling in on the frequency!"

This was a really good contact especially as it was on FM as opposed to SSB, CW or FT8. The tropo forecast for the area shows very good conditions off the west coast of Namibia so the propagation mode was probably marine ducting.

How does this compare to other contacts made on the 2m band? This is the equivalent distance of 2740kms from the South-West of Ireland.

It almost reaches across the Atlantic to Newfoundland. However, it's also the same distance from Ireland to the Canary Islands off the west coast of Africa.

Most years, we have openings from Ireland and the South-West of the UK to the Canary Islands (EA8) via marine ducting tropo. It's unusual but not rare.

I suspect that the contact from South Africa to St.Helena is pretty much the same, unusual but not rare. If anyone looks at the topography of St.Helena then they can see that the populated area on the north-west of the island is blocked to the south-east by hills. ZD7GWM is in the centre of the island with a better take off and perhaps this is what made the difference. When similar ducting happens again...and it will, another contact may well be possible.

Is a contact possible from South Africa to South America. The distance is about 5800 kms, over twice the distance of the South Africa - St.Helena contact. Unlikely.

Although I seem to remember a news item from a few years back where someone in Namibia did tests on 2m with someone in Brazil?