Very quiet on 28 MHz - Mon 22nd March 2021

 

Unlike the previous day, the 28 MHz band on Monday the 22nd of March 2021 was very subdued with only a handful of FT8 signals heard on the band all day.

There were reports of an aurora to the north of Europe last night so perhaps that is the difference? i.e. yesterday was pre-aurora and today is post aurora?

The solar flux was just 77 which isn't far from the usual minimum value.

In a few weeks time, the Summer Sporadic-E season will be starting  which will bring good propagation on 10-metres regardless of what the sunspot cycle is like.

Conditions on 28 MHz - Sunday 21st March 2021

There was a slight jump in the solar flux to 80 today and there was a modest opening on 10m from here to parts of Africa, South America and the South Atlantic. According to the PSK Reporter website, I heard 74 stations on FT8 in 25 countries although in truth, I suspect the vast majority were buried in the noise.

There are two key points here when you look at the map. 

First of all, all the long distance F2 propagation is North-South. There were no East-West openings for example to Russia or the USA. That tells me that yes, the band was open but just about. 

The second thing is the Sporadic-E around Europe.

There was one weak opening to Slovenia and Austria when I noticed that the signals were audible. Some of the other signals may well have been either meteor scatter or weak Sporadic-E. The fact it was a Sunday and a lot of people were on the radio probably helped.

These are the stations that were over 2,500kms...

Txmtr Band Mode Distance Time (UTC)
CX5ABM 10m FT8 10709 km 17:54:29
PY5EG 10m FT8 9475 km 17:56:14
PY2OKB 10m FT8 9195 km 17:49:44
PY1JG 10m FT8 8982 km 17:52:29
PY1EU 10m FT8 8978 km 18:03:44
9J2MM 10m FT8 8297 km 16:00:29
9J2BS 10m FT8 7971 km 13:15:59
ZD7JC 10m FT8 7542 km 10:09:14
ZD7MY 10m FT8 7540 km 12:01:44
ZD8HZ 10m FT8 6673 km 17:49:14
9K2OW 10m FT8 5215 km 09:39:59
5T5PA 10m FT8 3518 km 17:51:44
EA8DFQ 10m FT8 2705 km 18:02:14

VP8NO 10m FT8 12351 km 17:47:59

Meteor explodes over the English Channel (20th of March 2021) - Were there any unusual radio signals??

On Saturday the 20th of March 2021 at approximately 14:53 UTC, a large meteor entered the earths atmosphere and burnt up over the English Channel.

According to a news report on the BBC website, this resulted in a large sonic boom as the meteor exploded.

Massive bang over #Dorchester around 20 minutes ago. Any sound nerds know what it is? #Dorset. pic.twitter.com/tHnHEifhhF

— Ollie Peart (@Ollieep) March 20, 2021

The meteor probably burnt up at a height of about 100kms which meant it would have been visible over quite a large area.

The photo above is from a dashcam on the island of Jersey.

This image from a weather satellite shows a flash over the Bristol Channel. 

Note however how much the photo is distorted which suggests that perhaps the photo was taken from a geostationary satellite over the equator and it is looking at the UK from a low elevation. That 'white dot' may not be actually over the Bristol Channel but it could be maybe 200kms further south. Note that while the clouds in this picture might be say 5kms above the ground level, the flash is about 100kms up.

There are other reports of a meteor burning up over the English Channel.... see HERE

**

Any unusual radio signals???

As this large meteor burnt up at a height of about 100kms above the earths surface, it would have left a trail of ionised gas in its wake.

I know it's a long shot but I wonder if anyone noticed any unusual signals at about 14:53 UTC on the 20th of March 2021?

Example. Were you on a digital mode like FT8 on 28 MHz, 50 MHz or 70 MHz? If your WST-X programme is still running from Saturday then you can go back and have a look. Your logbook of received signals is up on the PSK Reporter website for 24 hours after the event.

Example. Were you listening on the FM band (88-108MHz)? Were you using an SDR receiver and recording the band?

If you heard anything then get in touch or leave a comment.

* * *

Update 25th March 2021: In the hours after the meteor burnt up, I had a look at the PSK Reporter website and looked at some of the FT8 signals that were heard by stations in the UK, Ireland & France on the 28 MHz & 50 MHz bands.

(FT8 is a digital mode where signals are sent in 15 second bursts)

I have put together maps below for several stations. My own conclusion is that there are signs of some meteor scatter activity over the north coast of Brittany and Normandy but I don't think we can be 100% sure about any individual reception report.

I'd suggest that the results show that something happened in this general area but I'm not sure we can infer anything about the exact direction the meteor was traveling.

I have included the time stamps for each of the paths and you can decide for yourself if they are indeed due to this meteor burning up.

See below...

Back on 28 MHz as my 10m antenna returns from the dead

 

Back in mid-February 2021, my vertical half-wave for 10-metres cracked into two pieces after a windy few days. After seeing half of the antenna sticking out of a hedge, I had pretty much given up on it and thought it was a dead duck.

I looked at other options such as buying a new antenna or building something and didn't really decide on anything.

With the current spell of mild dry weather over Ireland, I finally got around to examining the broken antenna this weekend. It had a reasonably clean break so I cleaned it up, cut off a damaged section with a hacksaw, put in a slot for the lower section to compress and tighten and hey presto, it's back in action!

As the antenna was so wideband anyway, losing 10cms or so of it had no impact on the VSWR at the bottom end of 28 MHz.

I left on the radio on 28 MHz today and this is what I heard on the FT8 frequency...

There is evidence of some weak Sporadic-E around Europe as well as some F2 propagation to Israel, Africa and Brazil. The solar flux is down at 74 which is pretty much rock bottom.

I have to admit that I have a soft spot for the 10-metre band. Even though I have no real interest in making contacts, it's good to be back listening on the band again.

The DL7APV 8 x 9 Element Antenna Array for Band 2 (88-108 MHz)

One of my interests is listening for long distance radio signals on the 88 to 108 MHz band which is  otherwise known as Band 2 or as simply the FM band to the general public. I recently came across this impressive antenna array from Bernd, DL7APV in Germany.

He is using an array of eight bayed 9-element Band 2 beams mounted on a rotatable base which is normally used for moon bounce on the higher VHF & UHF bands.

According to DL7APV, the antenna array has an impressive gain about about 14 to 15 dBd with a beam width of about 10 degrees.

The individual antennas are the 9-element 3H-FM-9M19 - Modell 2019 from Antennenland which retail at €109 each.

Despite the fact that the antenna has 9 elements, a lot of them are used to make the antenna broadband. It seems to have the same gain as say a narrowband 4 to 5-element Yagi.

For more details on this array, how it goes together and what was heard, check out DL7APV's 3-metre page on his website.

64% of consumer radio devices sold in Europe are analogue only

 

A recent news item on the RADIOWORLD website mentioned that a tech company named Frontier Smart Technologies had stated that 64% of consumer radio devices sold in Europe in 2020 were analogue only.

Just think about that for a second. Despite the fact the DAB+ digital radio networks are being rolled out across Europe at the moment, nearly two thirds of the consumer radio devices now being sold can't receive it.

This suggests that FM radio on the 88 to 108 MHz band in Europe will be around for a long time to go yet.

Did a 143 MHz signal cross the North Atlantic back in 1959???

There's a story that way back on the 14th of August 1959, there was a partial trans-Atlantic  contact between two MARS stations operating at 143.950 MHz!

(MARS - The Military Auxiliary Radio System is a United States Department of Defense sponsored program, established as a separately managed and operated program by the United States Army, and the United States Air Force.)

W1REZ in Fairfield, Connecticut was operating under the MARS callsign of AF1REZ and the station at the eastern end of the path was using the call AJ2GA at the Torrejón Air Base near Madrid in Spain.

It is alleged that each station heard the other station and audio recordings are supposed to exist. It was thought that the propagation mode was meteor scatter aided by tropo ducting formed by two high pressure systems over the North Atlantic.

I examined the locations and the path was around 7,800 kms. The date of the 14th of August would certainly tie in with the annual Perseids meteor shower.

Is this one of those stories that when it got retold multiple times, errors crept in and it became essentially like an urban myth?

Or did a VHF signal just below the 2-metre amateur radio band really cross the North Atlantic all those years ago?

Useful LC Filter Design Tool

I came across this online design tool may be of interest for anyone wanting to make their own low pass, high pass or band pass RF filters.

Link... https://rf-tools.com/lc-filter/

Description...

 LC Filter Design Tool

Calculate LC filters circuit values with low-pass, high-pass, band-pass, or band-stop response.

Select Chebyshev, Elliptic, Butterworth or Bessel filter type, with filter order up to 20, and arbitrary input and output impedances.

South African 8-metre beacon on 40.675 MHz heard in Portugal - 14th March 2021

 

Back in February, I had a post up about the ZS6WAB 8-metre beacon in South Africa transmitting on 40.675 MHz.

On the 14th of March 2021, someone in the Algarve in the south of Portugal claims to have heard it.

The 48-second recording which is in WMA format can be downloaded HERE

I fed the audio into the Spectrum Lab software programme and a screen grab of part of the signal is shown above.

The full morse signal reads... DE ZS6WAB DE ZS6WAB DE ZS6WAB BCN LOC KG46RB ...followed by a steady carrier.

The signal was heard by an experienced TV-DXer in the south of Portugal.

The distance works out as approximately 7,800kms.

As of the propagation mode??? ....F2? Multi-hop Sporadic-E? Trans-Equatorial propagation (TEP)? 

There are spots on the DX-Cluster for ZS stations on 28 MHz being heard in southern European countries.

"I started to received this in March during the afternoon.. At times it can be very strong, enough to copy the signal using a 20cm piece of wire as an aerial. There's often not much other activity in the 30-40MHz range when it's being received. Never heard it before 12.30 or after 16.30 gmt. On some days it can briefly appear just for a few minutes only. Hugh. "

Link...
1) My 40 MHz page... https://ei7gl.blogspot.com/p/40-mhz.html

EI2PMD - New Digital Gateway on 2m in Dublin

Update 14th March 2021: The new digital gateway in Dublin can now cater for DMR and D-Star modes.

IRTS News... New Multi-mode Digital Gateway, EI2PMD, Portmarnock, North Dublin

Ger, EI4HOB is pleased to report that the new Multi-Mode Digital Gateway, EI2PMD, located in Portmarnock, North Dublin, is now fully operational. The Gateway operates DMR, C4FM and D-Star on 144.825 MHz with a wide coverage of Dublin from the Northside down to the Tallaght and Dún Laoghaire areas. The DMR operates on Time Slot 2 and Colour Code 2. DMR Defaults to TG 2724, C4FM to IE-YSF-Ireland and D-Star to DCS 049 I. The Gateway operates 25 watts of power into a vertical colinear antenna. This gateway will provide a much needed digital service for the Dublin area. Good coverage reports have been received to date as borne out by the coverage maps.

* * *

Original post 22nd Jan 2021...In the last few days, a new Yaesu C4FM Digital Gateway for the Dublin area went on air.

Steve EI5DD writes..."A new C4FM Wires-X Gateway, EI2PMD, located in Portmarnock, Dublin, became active today (19th Jan 2021). The Gateway is operating on 144.825MHz and is linked to the CQ-IRELAND Room along with systems from Galway, Limerick, and Northern Ireland. YSF-Ireland, DMR TG 2724, and the Peanut App. We congratulate Ger EI4HOB for placing the first Digital system on air in the Dublin area."

As amateur radio digital repeaters and gateways have popped up around Ireland over the last few years, the one obvious omission was a digital repeater/gateway near the capital Dublin. This is in marked contrast to what usually happens with any new technology in that it usually starts near the capital or main city of a country and then spread outwards.

The new digital gateway is located in Portmarnock in the north side of Dublin City and it uses the 2m frequency of 144.825 MHz.

The approximate coverage is shown below...

From what I understand, the RF part of the gateway is confined to those using YAESU C4FM digital radios at present. It is hoped that in time, it will become a multimode gateway allowing DMR operation.

The gateway runs 20 watts into a Diamond omni-directional antenna.

Well done to EI4HOB and the North Dublin Radio Club for getting project up and running.

Example of a 3600km+ opening on 144 MHz from Ireland to Russia - June 2020

I'm always interested to hear about exceptional VHF contacts or reception reports and I like to keep a record of them here on the blog to encourage more people to get active on the bands. I meant to put up this post months ago but it kind of got delayed! 😄

Back on the 16th of June 2020, there was a Sporadic-E opening on 144 MHz over eastern Europe with stations in the south of Russia working into Poland and the Czech Republic. What was really unusual was that it coincided with another opening further west from the UK & Ireland to the Czech Republic, Poland and Ukraine.

The map above shows the signals that were heard by Mark, EI3KD on the 2m FT8 frequency of 144.174 MHz. 

This is a log extract of what EI3KD heard...

20200616_060700 -21 0.3 866 ~ CQ UC6A KN84
20200616_060730 -15 0.3 865 ~ CQ UC6A KN84
20200616_061200 -11 0.5 705 ~ CQ SQ9IVD KN09
20200616_061330 -14 0.2 1397 ~ EI3KD UX2SB -18
20200616_061330 -12 0.1 724 ~ YO6OBK UW8SM KN28
20200616_065200 -5 0.3 1562 ~ OE5JFL RZ6DD -18
20200616_065400 -19 0.2 1126 ~ CQ OK1VOF JN89
20200616_065430 -11 0.4 1800 ~ US5FZ RA6C -12
20200616_065430 -20 0.2 1126 ~ CQ OK1VOF JN89
20200616_065800 -22 0.0 1486 ~ CQ RX6DN KN94
20200616_065930 -26 0.1 1485 ~ EI3KD RX6DN R-07
20200616_070330 -11 0.3 1088 ~ CQ 9A2RI JN65
20200616_070400 -7 0.3 1089 ~ CQ 9A2RI JN65
20200616_070430 -22 0.2 1090 ~ CQ 9A2RI JN65

The normal maximum distance for single hop Sporadic-E is in the region of 2300 kms. What is highly unusual here is that EI3KD heard four stations in the south of Russia which were in the region of 3500kms!

The longest distance was RZ6DD at 3638kms.

The propagation mode was double hop Sporadic-E and this is clear from the fact that stations at the mid-way point were being heard as well. What's not so clear is if the signal was reflected off the ground at the half-way point or if it was chordal hop with the signal going between two Sp-E clouds without touching the ground. Whatever it was, it's an exceptional distance for 144 MHz.

This is an extract from DXMaps showing the DX-Cluster reports on that day on 144 MHz which were over 2500kms...

First a word of caution! As we all know, some mistakes occur with DX spots with people putting in the wrong band or info data. However, there are enough reports there to show that something special was going on that day.

You'll note that G4RRA in the SW of England also heard RZ6DD but at the slightly lower distance of 3356kms. See addendum below.

Why does this matter?... Because if someone in Ireland can hear a station in Russia on 144 MHz who is 3600+ kms to the east then why not across the North Atlantic to Newfoundland which is even closer at 3200kms?

Surely even if the chance of double hop Sporadic-E over the North Atlantic is incredibly small, there must be times when there are single hop Sporadic-E openings from either side with 1000kms of tropo making up the difference?

Wouldn't it be interesting to have a permanent online receiver based in Newfoundland with a beam pointing east and listening all of the time on 144 MHz? Stations in western Europe could then beam west and listen for their own signals online to see if the path is open. Or people could just log in and check if the receiver is hearing one of the Trans-Atlantic beacons?

At the moment, the North Atlantic path could open up on 144 MHz and nobody will ever know because there is no-one listening at the Canadian end.

Addendum: Thanks to Paul G4RRA for the following info...

Here's how my screen looked during that event. Both Mark and I are always looking out for events like this which are very rare indeed in my experience.

This was only the second one I've participated in in over 40 years, at least I managed a QSO in the first one !

R6DB also mentioned seeing me on KST chat.  ...de Paul, G4RRA

IRTS membership jumps 7.4% in 2020

The Irish Radio Transmitters Society (IRTS) is the national society for radio amateurs in Ireland and in the year 2020, they recorded an impressive 7.4% growth in membership. The IRTS membership numbers from the years 2000 to 2020 are shown above and as can be seen, the society is now just short of 1000 members.

The current surge in membership is attributed in no small part to the new IRTS initiative in holding free online training courses for IRTS members for the amateur radio examination. This has resulted in a large number of people joining the society and hopefully after lot of them pass the HAREC examination in the months ahead, we'll see plenty of new EI callsigns on the bands. 

The new IRTS online training courses are a welcome development and are long overdue. The old format of holding physical classes in one location with a very limited catchment area just wasn't working.

Applications are still being accepted for the next HAREC on-line course starting on March 30th 2021. The course will run on Tuesdays and Wednesdays for 8 weeks. The course is free for IRTS members and intending members and the closing date for applications is March 20th. Send expressions of interest to harectraining /at/ gmail.com.

The IRTS website can be found at https://www.irts.ie/

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.

Earth passes through stream of sodium atoms from the Moon once a month

 

There was an interesting article recently in the New York Times about how the Moon has a stream of sodium atoms coming off it and the Earth passes through it once a month. This 'tail' stretching 500,000 kms behind the moon comes from meteorites hitting the lunar surface.

I began to wonder if this would have any impact on Sporadic-E formation? I presume it doesn't as the tail is extremely diffuse and I think it's the dust from metallic meteors coming into the Earth's atmosphere that is the fuel for Sporadic-E propagation.

If however anyone found a weak correlation between Sporadic-E and the times of the new Moon, I would think this source would have to be reconsidered.

Addendum: This is the summary of an article which appeared in Nature in 1972...

THE radio reflexions from the sporadic E region (Es) of the ionosphere show unique properties within a narrow range of latitudes over the magnetic equator. Matsushita1 pointed out that the latitudinal variations of the maximum frequency reflected from the Es region and the solar daily range of geomagnetic H component each show a sharp maximum within about ± 3° from the magnetic equator, suggesting an association between equatorial Es and equatorial electrojet currents. Knecht2 has described the characteristics of equatorial Es (Es−q). First, it regularly occurs during daylight hours in a narrow belt along the magnetic equator; second, it is always transparent to probing by radio waves; third, it usually displays a well defined lower edge lying between 100 and 110 km, giving scattered and diffuse echoes above the principal echo; fourth, in well defined cases the diffuse echoes are contained below a sharp upper boundary that starts at about ƒ0E and increases in height with increasing frequency. The time of first appearance of the Es−q in the morning and the time of disappearance in the evening has been shown to be controlled by the age of the Moon, and this effect has been related to the corresponding variations of the equatorial electrojet2,3. Close correlations have been established between the dips in ƒEs and the H component of the magnetic field at equatorial latitudes4,5.

Link... https://www.nature.com/articles/physci237073b0

Addendum...

Anton Petrov gives some more information about this phenomenon in this video...

4000km+ opening on Band 2 from Indonesia to SE Australia - 7th Jan 2021

 

Very long distance openings on the VHF bands are always of interest and one such instance happened back on the 7th of January 2021 when Leigh, VK2KRR in New South Wales in Australia managed to log and record several FM Band 2 radio stations from Indonesia.

Normally with Sporadic-E propagation, the maximum distance is around 2300 kms. In this case, VK2KRR heard FM radio stations on the 88 to 108 MHz band from Indonesia, a distance of about 4000 to 5000 kms!

While a number of Indonesian stations were recorded, it looks as if it was difficult to get a positive ID on the exact location for each one. There was however a positive ID of RADIO FBI on the island of Bali on 91.8 MHz and at a distance of  4380 kms.

It's likely that the propagation mode was double hop or chordal hop Sporadic-E. While this is pretty common on lower frequencies like 50 MHz, it is much rarer at the Band 2 frequencies of 88 to 108 MHz.

A full list of videos from the opening on the 7th of January can be viewed HERE.

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

RTE to cease their DAB service at the end of March 2021

The Irish state broadcaster RTÉ have announced that their DAB digital radio service will cease at the end of March 2021. The DAB service was only transmitted from five sites near major cities and only covered 54% of the Irish population.

Sites: Three Rock (Dublin - 14kW), Clermont Carn (5kW), Kippure (15 kW), Spur Hill (Cork - 10kW), Woodcock Hill (Limerick - 10kW).

A recent JNLR report, Radio in a Digital World, compiled by Ipsos/ MRBI, found just 0.5% of adults listened to DAB. 77% of adults in Ireland listen to radio on FM.

Analysis... I'm sure there will be some people outside of Ireland who will look at this story in terms of a digital DAB V analogue FM narrative and conclude incorrectly that the attempt to replace FM with DAB failed in Ireland.

The reality was that DAB as a service was never really rolled out in Ireland and nearly half the population couldn't receive it. The radio stations on the DAB platform were the usual RTÉ suite of stations on FM as well as a few more like RTÉ Gold, RTÉ 2XM, RTÉ Radio 1 Extra, RTÉ Pulse, and RTÉjr Radio. There were no commercial radio stations so the choice was extremely limited.

DAB really offered very little incentive to buy a digital radio as nearly everything of interest could be heard nationwide on the FM service which has saturation coverage. As a service, it might have been interesting back in say the 90's but in todays world of podcasts, audio books, streaming services, smartphones, etc, a DAB radio looks like an antique.

I remember showing a DAB radio to someone back around 2005. The first question I got was 'Can I get BBC radio on it?'. Answer no, just the usual RTÉ stations plus a few more. No wonder it failed.

Maybe there will be a new digital standard like DAB+ introduced in Ireland in the future but it looks like the analogue FM service from 88 to 108 MHz is going to be around for a long time.

Timeline of DAB in Ireland
On-Air (tests): January 2006 to June 2006
On-Air (tests): December 2006 to November 2008
On-Air (public service): December 2008

On-Air (tests): to March 2001

Closure: April 2021

Free Newsletter - The Communicator March-April 2021

 

The Surrey Amateur Radio Club in western Canada produce a high quality newsletter every two months called The Communicator.

The cover and index is shown above for the March-April 2021 edition and you can find the download link HERE

Denmark heard on 144 MHz... 28th Feb 2021

 

I noticed this morning that I had heard OZ1BJF in Denmark on Sunday via FT8 on 144 MHz. It's unusual for me to hear a signal like this at the distance is 1387 kms as I'm only using a simple home made Slim Jim vertical half-wave in my attic.

Was it via meteor scatter? Tropo? There is a high pressure system over the UK so I suspect it might have been tropo.

I also heard PD1DL in the Netherlands at 921 kms which is another sign of good tropo.

I've been on the radio for the best part of 40 years and it still amazes me just how far signals travel on VHF. I never get that sense of wonder with HF bands like 20-metres.