Wednesday, July 22, 2020

Articles about using Ferrite Cores as RF chokes


Ferrite cores are used everywhere in radio from RF transformers to filters to chokes. They are often made from different materials that will have different properties at different frequencies and they are often seen as a bit of a Black art.

I came across some recent articles on using ferrite cores as RF chokes and I'm posting the links here so I don't lose them.

1) QRM GURU : The truth about ferrites... This website looks at a selection of ferrite cores and how they can be use to prevent interference at HF & VHF.

2) K9YC ... This website has a detailed PDF on using ferrite cores as RF chokes.

Monday, July 20, 2020

Australian authorities turn down request for 70 MHz allocation

There was a news item on the Internet recently about how the Australian regulator was not considering an allocation at 70 MHz for radio amateurs.

“We note the continued interest in this band from the amateur community. The ACMA will not be further investigating this matter at this time.

The ACMA considers that operating amateur services in this frequency range is not feasible as it would be inconsistent with ITU Radio Regulations and existing services are already operating in the frequency range. 

This frequency range is used by a variety of fixed and land mobile services as supported under the VHF mid band (70–87.5 MHz). Class licensed devices authorised under the LIPD Class Licence operate in the frequency range 70–70.24375 MHz.”

This was the reply to a submission to an earlier submission by the Wireless Institute of Australia (WIA) to the ACMA which essentially consisted of a single sentence... "10. The WIA still has an interest in an allocation at 70 MHz."

ITU Region 3... As can be seen from the map below, Australia is in ITU Region 3 while nearly all of the 70 MHz allocations are in Region 1 countries.


It's a pity that something like a 4m beacon couldn't be established in Australia or even a or a few experimental licences for the band.

It would be interesting to see if say someone in Perth on the west coast (VK6) could investigate if there is a multi-hop Sporadic-E path across the Indian Ocean to South Africa or up to the Middle East.

What would be good is for one of the smaller countries in Region 3 to give a small allocation for the 4m band which would then set a precedent. Even a 200 kHz wide segment of spectrum dedicated to weak signal modes would satisfy most requirements.

Saturday, July 18, 2020

Video: Transceiver performance for the HF - VHF - UHF operator... by NC0B


The Sutton and Cheam Radio Society recently uploaded a video on YouTube titled Transceiver performance for the HF - VHF - UHF operator.

No matter what bells and whistles a radio has, the most important parameter is how it performs on the air in terms of reception and transmission of signals.

The presentation is given by Rob Sherwood, NC0B and it goes into quite a bit of technical detail on how to judge the RF performance of a transceiver on the HF or VHF bands.

Some key points...

  • Sensitivity isn't the most important parameter on HF
  • Low signal performance is often determined in modern times by urban noise
  • While a dynamic range of 100dB is common on HF, it's usually a lot worse on 2-metres and above
  • 2m & 70cms tranceivers are 10-25 years behind HF versions

If you are serious about getting the most from your station then it's well worth watching.

Fast forward to 2:45 for the start of the presentation...



Link...
1) http://nc0b.com/

Friday, July 17, 2020

What is the IARU??


The IARU is the International Amateur Radio Union and it represents the interests of radio amateurs worldwide at international conferences and with national regulators through the various national societies.

A 3-minute promo video outlining their work can be seen HERE

The national society for radio amateurs in Ireland is the IRTS - the Irish Radio Transmitters Society.

Thursday, July 16, 2020

Unusual Sporadic-E opening on 144 MHz in N Europe hints at possibility of Trans-Atlantic contact

In this post, we'll look at a recent Sporadic-E opening on 144 MHz in northern Europe and what it might mean for a trans-Atlantic contact on 2 metres.

First, the opening...


There was an extensive opening on 144 MHz on the evening of Monday the 13th of July 2020 as can be seen from the graphic above from DXMAPS.COM

Sporadic-E openings on 144 MHz are reasonably common in Europe but they are usually much further south. Radio amateurs in say the UK or Ireland are likely to catch several openings to say Spain or Italy during the months of May, June and July every year.

It is very unusual to have a Sporadic-E in northern Europe and it is rare for the radio amateurs in the UK or Ireland to hear the likes of Finland or the Baltic states on 144 MHz via Sporadic-E.

While the graphic above gives an illustration of the extent of the opening, let's have a look at some specific examples. The maps below generated by FT8 reports on the PSKReporter website are useful for examining the extent of the opening.

EI2FG on the south coast of Ireland was one of the most westerly stations listening on the FT8 frequency on 144 MHz for the opening.


The longest path was to UA1ALD at 2416 kms and the signal was +9dB which was certainly strong enough for an SSB contact. Note the beam heading... 55 degrees. OH6KTL was up at 44 degrees.

Note also that the path was open only to the northern part of Estonia, there was nothing further south.

UA1ALD... This is the FT8 sent/receive map for UA1ALD.


Note how concentrated the footprint is in the UK. There is no-one from the south-east of England shown.

ES4RM... Note how the results for ES4RM in the north of Estonia are pretty much the same with nothing from the south-east of England.


OH2FQV... This is the map for OH2FQV in the south-east of Finland.


Note the difference in the footprint in the UK compared to UA1ALD. This time, there are a lot more stations in the south-east of England except for an area south of London.

This suggests that the Sporadic-E cloud responsible for the 144 MHz opening was probably somewhere over the north of Denmark. What each station worked or heard was dependent on where they were relative to this Sporadic-E hot spot.

It's also amazing to see just how many stations in England are using FT8 on 144 MHz!

GI6ATZ... This is the map from GI6ATZ in the north-east of Ireland.


The more northerly location of GI6ATZ results in stations in Lithuania and Latvia being heard.

G7RAU... The send/receive map for G7RAU in the south-west corner of England shows that there was a 2445 km path open to OH6CT in the north of Finland, just three degrees or so south of the Arctic Circle.


Again, note the beam heading from G7RAU to OH6CT which was 35 degrees. The signal was -2dB which would have been enough for a CW contact.

OH6CT... From OH6CT's viewpoint, he was hearing the south-east of England this time and the rest of the UK and Ireland was missing.


Trans-Atlantic on 144 MHz??? .....First of all, lets recap.

a) Both G7RAU and EI2FG heard or were heard by stations on FT8 in Finland at beam headings of 35 and 44 degrees respectively i.e. very far to the north.

b) Both G7RAU and EI2FG heard or were heard at -2dB and +9dB respectively at a distance of about 2400 kms. Note that this is about the maximum distance for one hop Sporadic-E.

Now lets look at the path from St.John's in Newfoundland to the south-west of Ireland and the north-west of Spain.


First off, the beam headings of 68 and 80 degrees are a lot further south than the beam headings experienced by EI2FG and G7RAU. If there is a Sporadic-E opening on 144 MHz in the north of Europe then why wouldn't it also happen out over the North Atlantic?

I know some might argue that Newfoundland is closer to the geomagnetic pole and that might impact on Sporadic-E formation but Newfoundland is also further south than Ireland.

While the one hop of 2400 kms ends up in the Atlantic, the remaining distance to span isn't huge. Just another 800 kms or so would reach the south-west of Ireland. Just another 1000 kms would reach Spain. Both of these distances could be easily bridged by a tropo duct forming over the ocean to the west of Ireland or Spain.

Surely there must be times when there are Sporadic-E openings on 144 MHz to the east of Newfoundland? And there must be times when these openings coincide with tropo over the eastern part of the Atlantic? I would argue that there must be times when the path across the North Atlantic on 144 MHz is open although I would acknowledge that these openings are pretty rare.

I'd suggest that one of the biggest problems is the lack of activity on the western end. I don't believe there is anyone in Newfoundland transmitting or listening on 2-metres for signals across the Atlantic. For all we know, some of the trans-Atlantic CW beacons in Ireland, England or France may well have made it across the ocean to Newfoundland but there was nobody there listening to report it.

Look at the distance from Newfoundland to the Azores (CU). That's within Sporadic-E or meteor scatter distance and yet as far as I am aware, there has never been a contact on 144 MHz from Newfoundland to the Azores.

Solution... The most obvious one to me is the establishment of a station on Newfoundland that can be operated remotely, just like D4VHF on the Cape Verde Islands. Something like two stacked 5-element Yagi antennas beaming at 70 degrees with 100 watts?

Digital modes like FT8 could be used to see if the path was viable by transmitting and receiving on the 2-metre frequency of 144.174 MHz.

It is of course easy to say how it might happen, it's another thing for a group to implement it.

Monday, July 13, 2020

IC7300 online jigsaw


This might be one for when the bands are closed 😊

There is an online jigsaw for the ICOM IC-7300 at this LINK

Sunday, July 12, 2020

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.

Friday, July 10, 2020

IARU Region-1 to discuss possibility of 40 MHz & 60 MHz allocation


Every few years, the member societies of the International Amateur Radio Union (IARU) meet up to discuss various proposals and plans. Due to the COVID-19 pandemic, there will be a virtual meeting online of the IARU Region-1 (Europe, Middle East & Africa) in October of 2020.

One of the proposals for the meeting is to discuss the possibility of a 600 kHz wide allocation at 40 MHz and 60 MHz.

Links...
1) Conference website
2) Documents

Thursday, July 9, 2020

ESA: How to get pictures from the International Space Station via amateur radio


The European Space Agency have just released a video on YouTube explaining how to receive Slow Scan TV pictures via amateur radio.

The first video is about how to find the International Space Station...



There are plenty of videos about SSTV but this one is aimed at the general public who might never have heard of amateur radio before. The video instructs viewers how to receive pictures using a web based SDR in the SW of England.

This second video shows what software to use to decode the SSTV signals from an online SDR. This one is for those that use the Windows 10 operating system on their PC..



There are similar videos for users of other operating systems.

See the links below...
Windows 7... https://youtu.be/UKf7h0wBymY
Mac OSX... https://youtu.be/VOPxJ7UpUAI
Ubuntu... https://youtu.be/urNPrpEcAYY
iOS... https://youtu.be/B1GFg41UAHA
Android... https://youtu.be/Y2CS9mtv2hU
Rasberry Pi OS... https://youtu.be/A3Z6pUv6XEA

Tuesday, July 7, 2020

COMREG release Radio Frequency Plan for Ireland - July 2020


The Irish communications licencing authority COMREG have just released a document titled 'Radio Frequency for Ireland'.

You can download it HERE

Sunday, July 5, 2020

Upgrade of the D4VHF station VHF & Microwave antenna systems

Over the last few years, the D4VHF station in the Cape Verde Islands has made some amazing contacts on the 144 MHz & 432 MHz bands across the Atlantic to the Caribbean and also well into Europe. Most of these VHF and UHF contacts are in the region of 3000 to 6000 kms.

They recently made some major changes to their antenna system for 2-metres, 23cms and 12 cms.

2-metres... Up to recently, the D4VHF team were using a single 12 element Yagi on 144 MHz. They have now installed three crossed 5-element Yagis.


The photo above shows the three new 144 MHz crossed Yagis marked A, B and C. As can be seen, the three crossed Yagis are stacked vertically.


This second photo above shows the stacked Yagis from a different angle. Each individual crossed Yagi is made of two 5-element beams in a X configuration. These two beams are  fed 90 degrees out of phase relative to each other and this achieves Right Handed Circular Polisation (RHCP).

Comparison - Old 12 element Yagi V New Stack of three 5-element RHCP Yagis... How do the two antenna systems compare? Here are some rough calculations...

Gain... The old 12 element Yagi which was horizontally polarised probably had a free space gain of about 13dBd.

As for the new stack? Let's take the gain of 5 element beam to be 9dBd. There is a stack of three so lets add 5dB giving a gain of 14dBd. Lets assume that there is some loss stacking as they will probably not get the full three times power so we'll subtract 0.5dB giving 13.5dBd. There is also a 3dB loss due to the fact that it is using circular polarization and we're down to about 10.5dBd.

So we have an estimated 13dBd for the old 12 element and 10.5dBd for the new antenna system, a drop of about 2.5dB.

Linear Vs Circular Polazation... When both the receive and transmit antennas are horizontally polarized at either end of a propagation path and nothing changes then everything is fine. However when the path is several thousand kms in length, will it always stay the same? If there happens to be a Sporadic-E hop involved then the polarization of the signal is constantly changing.

If say a horizontally polarized antenna receives a horizontally polarized signal then there is no loss i.e. 0dB. If however a signal gets twisted and arrives at more than 45 degrees relative to the receive antenna, then the losses can be anything from -3dB up to -20dB.

With very weak FT8 signals buried in the noise and with 15 second transmissions, this polarization fading can mean incomplete contacts or at the very least, it slows things right down resulting in fewer contacts during say a Sporadic-E opening.

With a circularly polarized antenna, the loss is never more than -3dB. So even though the gain of the new antenna stack is slightly less, the lower loss due to polarization changes should result in more completed contacts.

Beamwidth... The other change between the new and old systems is the beamwidth.

The beamwidth of a beam is measured by its -3dB points i.e. where the gain of the antenna has dropped by 3dB.

For the old 12 element antenna with a gain of about 13dBd, the beamwidth was about 32 degrees.

With the new antenna array, the vertical stacking will compress the radiation in the vertical plant and direct more of it down towards the horizon. For the radiation in the horizontal plane i.e. left/right, it should have pretty much the same beamwidth as a single 5 element which is about 54 degrees.

This map shows the beam headings from Cape Verde to Europe...


With the old 12 element pointing at 35 degrees, the 32 degree beamwidth covered about 19 to 51 degrees.... roughly from Wales to the south of Italy.

With the new array for the same 35 degree example, the 54 degree beamwidth will extend from 08 to 62 degrees. This means that there is more power heading towards say Ireland, Scotland and the Azores.

It also allows more power to head towards the Eastern Mediterranean. It seems unlikely that someone from say Greece or Israel could work D4VHF on 144 MHz as there is a lot more land and less sea for a marine duct. But that's not to say its impossible, especially at this more southerly latitude.

Microwave Bands.... They also made some improvements to their set up for the microwave bands of 23cms and 13 cms.


The photo above shows the 1-metre homemade dish for 1296 MHz and 2300 MHz. The gain on 23cms is approx 19dBd while the gain on 13 cms is about 24dBd. They will be adding an elevation motor so that it can be used for moonbounce.


This is another view of the same dish but it also shows the 80cm dish on the right for accessing the QO100 satellite in geostationary orbit (2.4 GHz up, 10 GHz down).

In conclusion... As you can see, the D4VHF team are constantly improving their station on Cape Verde and are opening up new paths that we didn't even know existed.

If you would like to support their work then they have a PayPal link HERE

Friday, July 3, 2020

5000km plus opening on 144 MHz from Cape Verde Islands to Italy, Slovenia & Croatia - 2nd July 2020


On Thursday the 2nd of July 2020, there was another remarkable opening on 144 MHz between Cape Verde Islands off the west coast of Africa and Italy, Slovenia & Croatia.

This isn't the first time that this has happened but any terrestrial opening on 144 MHz which reaches 5000kms or more is always special.


This edited list shows the stations that heard by D4VHF in Cape Verde. It also lists those hearing D4VHF on FT8 but not weren't heard by them (in order of distance)...

Txmtr Rcvr Band Mode Distance Time (UTC)
D4VHF S51ZO 2m FT8 5028 km 19:09:59
9A5BWW D4VHF 2m FT8 5013 km 19:02:42
D4VHF 9A6NA 2m FT8 5013 km 18:51:56
D4VHF S50TA 2m FT8 4885 km 19:17:44
D4VHF S57A 2m FT8 4809 km 18:41:59
D4VHF IV3/HB9CAT 2m FT8 4798 km 18:27:59
D4VHF IV3GTH 2m FT8 4792 km 18:41:56
9A5CW D4VHF 2m FT8 4790 km 19:17:57
D4VHF IV3GBO 2m FT8 4786 km 19:11:44
9A3CX D4VHF 2m FT8 4776 km 19:03:12
D4VHF IV3BLQ 2m FT8 4776 km 19:17:41
D4VHF 9A5CW 2m FT8 4774 km 19:17:14
D4VHF 9A3K 2m FT8 4774 km 19:15:44
D4VHF 9A1UN 2m FT8 4766 km 19:04:29
9A2RD D4VHF 2m FT8 4766 km 19:01:41
IK3VZO D4VHF 2m FT8 4643 km 18:35:12
D4VHF IW3GJF 2m FT8 4639 km 18:35:29
IZ3NOC D4VHF 2m FT8 4636 km 18:32:11
D4VHF IK4DRY 2m FT8 4624 km 18:59:29
D4VHF IK4FMT 2m FT8 4596 km 18:59:26
D4VHF IW4AZY 2m FT8 4548 km 19:11:15
D4VHF IK2MKS 2m FT8 4528 km 15:51:44
IK2LHP D4VHF 2m FT8 4517 km 15:57:56
IK0SMG D4VHF 2m FT8 4506 km 16:44:56
D4VHF IW0FFK 2m FT8 4505 km 16:46:44
D4VHF IZ2MHO 2m FT8 4480 km 15:52:11
D4VHF G7RAU 2m FT8 4086 km 16:02:14

FT8 screenshot from D4VHF
This is a list of the 20 stations in Italy, Slovenia & Croatia that D4VHF actually completed a contact with on FT8...

2020-07-02 15:49:15 IZ2MHO JN45 144.175900 FT8 +03,-06 
2020-07-02 16:30:30 IK0SMG JN61 144.175900 FT8 -03 -11 
2020-07-02 18:25:00 IK3VZO JN55 144.174900 FT8 -19 -01 
2020-07-02 18:28:00 S50TA 144.174900 FT8 +08 +01 
2020-07-02 18:28:30 IZ3NOC 144.174900 FT8 -03 -12 
2020-07-02 18:33:00 IV3NDC 144.174900 FT8 -06 -06 
2020-07-02 18:34:30 IW3GJF 144.174900 FT8 -12 -06 
2020-07-02 18:36:45 IV3GTH JN65 144.174900 FT8 -17 -11 
2020-07-02 18:37:45 IZ3QFG 144.174900 FT8 -05 
2020-07-02 18:42:30 S57A JN65 144.174900 FT8 +02 -06 
2020-07-02 18:44:00 IK4FMT JN54,144.174900 FT8 -15 -21 
2020-07-02 18:46:45 IK4DRY 144.174900 FT8 -11 -07 
2020-07-02 18:52:00 9A3CX JN65 144.174900 FT8 +00 -01 
2020-07-02 18:57:30 9A3K JN65 144.174900 FT8 +05 +01 
2020-07-02 18:58:15 9A6NA JN86 144.174900 FT8 -12 -19 
2020-07-02 19:02:00 9A2RD JN65 144.174900 FT8 +13 -09 
2020-07-02 19:02:45 9A5BWW JN86,144.174900 FT8 -05 -16 
2020-07-02 19:04:30 9A1UN JN65 144.174900 FT8 -10 -07 
2020-07-02 19:05:45 IV3GBO JN66 144.174900 FT8 +17 -07 
2020-07-02 19:12:30 9A5CW JN65 144.174900 FT8 -06 -13 

Another screenshot from D4VHF
Mode of Propagation... How exactly did these 5000km signals travel so far on 144 MHz? It seems likely that it was via a combination of a marine duct from Cape Verde up as far as Morocco and via Sporadic-E from there to Italy.


The tropo prediction map from Pascal, F5LEN shows some tropo in the Mediterranean Sea so that can't be discounted either. However, there must surely been at least one Sporadic-E hop in there somewhere.

Full D4VHF log including the EA & EA8 stations shown below...

Tuesday, June 30, 2020

RSGB Video: Antennas for small gardens with Steve Nichols, G0KYA


The RSGB have recently put a video up on YouTube entitled "Antennas for small gardens with Steve Nichols, G0KYA"

Most radio amateurs have modest or small gardens and those on HF will have an interest in getting the best antenna working in a limited space.

In this video which is 80 minutes long, Steve G0KYA presents plenty of options for radio amateurs to consider.



Note that the video doesn't really start until 1:40 so fast forward to skip the static screen.

Monday, June 29, 2020

New 70cms repeater in the west of Ireland to improve coverage of the Southern Ireland Repeater Network

The Southern Ireland Repeater Network is made of seven interlinked repeaters on 2-metres and 70-cms and covers the southern half of Ireland. The coverage map as of June 2020 is shown below...


There are now plans to fit a new 70-cms repeater on the summit of Mahera in Co.Clare in the west of Ireland. This is an excellent site in terms of coverage and is one of the main transmission sites used by the state broadcaster RTE for radio and TV.

An approximate coverage map of the new proposed 433 MHz repeater is shown below....


The most significant change is that it will add Galway City to the Southern Ireland Repeater Network which is a welcome development.

The eastern part of Limerick City should also be covered although Woodcock Hill will screen signals to the western part of the city.

The coverage map also suggests very good coverage of the main road from Limerick to Galway as well as the eastern part of Co.Galway and the part of the midlands.

From my understanding, the new repeater will be installed once the travel restrictions for COVID-19 are eased.

Link...
1) Southern Ireland Repeater Network

Sunday, June 28, 2020

6000 km plus contact made between the Canary Islands & Kazakhstan on 70 MHz - 18th June 2019


I recently came across details of a remarkable 70 MHz contact that was made on the 18th of June 2019 between EA8DBM in the Canary Islands and UN7MBH in Kazakhstan. It's possible that someone hadn't noticed the date on the FT8 screen capture when posted online and thought it was from 2020 instead.

Despite the fact that it's over a year old, it was still an interesting contact as it was in the region of 6,112 kms. As you can see from the screenshot below, the contact was made via the FT8 digital mode.


While most Sporadic-E contacts on 70 MHz might be in the region of say 1500 to 2200 kms, the 6000 km plus distance for this contact suggests that it may have been triple hop Sporadic-E.

Triple hop Sporadic-E on 50 MHz is interesting but not that unusual. After all, most of the 6-metre contacts between Europe and the USA are triple hop or more.

However as the frequency get higher, a higher level of ionisation is required. At 70 MHz, single hop Sporadic-E is very common, double hop is a more unusual but triple hop is more exceptional.

I searched on the net for more information on this remarkable contact but there didn't seem to be anything about it. I thought I'd make a post about it so that at least a record of it now exists.

I know that there have been triple hop contacts from the north-west of Europe to the Arabian Peninsula but I don't think any of those exceed 6000 kms.

Saturday, June 27, 2020

RSGB video on VHF Propagation

The RSGB recently released a video on YouTube which outlines the basics of VHF propagation. While it doesn't go into any great detail, it is a good primer on the subject.



"Steve Nichols, G0KYA - Chair of the RSGB Propagation Studies Committee - narrates this presentation about VHF propagation.  The presentation was written by John Worsnop, G4BAO and the RSGB would like to thank Mike Willis, G0MJW for allowing use of his charts and diagrams."

Global Magnetic Anomaly on the 23rd of June 2020...

It has been reported that there was a Global Magnetic Anomaly on the 23rd of June 2020. Starting at about 06:30 UTC, there was a period of about 30 minutes where the magnetic field oscillated like a sine wave with a period of about 10 minutes.

Scientists call this phenomenon a "pulsation continuous" or "Pc" for short.

SpaceWeather describes as... "Imagine blowing across a piece of paper, making it flutter with your breath. Solar wind can have a similar effect on magnetic fields. Pc waves are essentially flutters propagating down the flanks of Earth's magnetosphere excited by the breath of the sun. During more active phases of the solar cycle, these flutters are easily lost in the noise of rambunctious geomagnetic activity. But during the extreme quiet of Solar Minimum, such waves can make themselves "heard" like a pin dropping in an silent room."


Image from Stuart Green

Pc waves are classified into 5 types depending on their period. The 10-minute wave on June 23rd falls into category Pc5. Slow Pc5 waves have been linked to a loss of particles from the van Allen radiation belts. Energetic electrons surf these waves down into Earth’s atmosphere, where they dissipate harmlessly.

I looked back at my WSPR reports for 28 MHz but didn't see anything unusual. Perhaps it might have had more of an impact on the lower bands.

Links...
1) Magnetic Pulsations

Tuesday, June 23, 2020

4000 km+ VHF path from Cape Verde to the UK opens up - June 2020


On the 23rd of June 2020, the VHF path from Cape Verde Islands off the west coast of Africa to the UK opened up again. The following stations in the UK and France reported D4VHF on FT8 on 144 MHz... Updates below...

Rcvr Band Mode Distance Time (UTC)
G4LOH 2m FT8 4098 km 18:23:14
GW4VXE 2m FT8 4280 km 18:15:12
G7RAU 2m FT8 4086 km 17:39:14
F8DBF 2m FT8 3963 km 17:15:44
G3NJV 2m FT8 4090 km 16:23:14
GW6TEO 2m FT8 4249 km 15:45:14
G4RRA 2m FT8 4211 km 15:33:14
GW7SMV 2m FT8 4317 km 15:33:14
M0BKV 2m FT8 4181 km 15:30:14
G8IXN 2m FT8 4110 km 15:04:44
G4ELI 2m FT8 4101 km 15:04:44

As can be seen from the location of the stations, this seems to be the usual maritime duct which can last for days.

The DX spots from the cluster shows that D4VHF was on SSB as well and they were also on 432 MHz...

G4LOH 432200.0 D4VHF 16:21 23 Jun IO70JC HK76MU 57 ssb Cape Verde
G7RAU 144174.0 D4VHF 16:11 23 Jun IN79JX HK76MU 432100 ft8 9+ Cape Verde
G4RRA 144174.0 D4VHF 15:48 23 Jun IO80BSHK76MU sri here ! Cape Verde
GW6TEO 144174.0 D4VHF 15:41 23 Jun IO71LPHK76MU tnx gl Cape Verde
GW7SMV 144174.0 D4VHF 15:34 23 Jun hrd cq -18 Cape Verde 
G7RAU 432100.0 D4VHF 15:34 23 Jun IN79JX HK76MU +17 ft8, gl Cape Verde
G7RAU 144174.0 D4VHF 14:50 23 Jun IN79JXHK76MU plus tropo Cape Verde
G4LOH 144174.0 D4VHF 14:32 23 Jun IO70JC HK76MU 59+20dB CQ Cape Verde
GW0KZG 144174.0 D4VHF 14:31 23 Jun IO71LWHK76 144.174 FT8 Tn Cape Verde

The tropo prediction map from Pascal, F5LEN shows that the path is open...


If you are used to VHF reports then you'll know that this path opens quiet often. It's easy to be blasé about it but it's worth remembering that the stations shown above in the UK are in the region of 4100 to 4300 kms from Cape Verde Islands.

That's the equivalent distance from London to Nova Scotia in Canada... and this is on 144 & 432 MHz!

The path from the UK to Cape Verde looks reasonable for the 24th & 25th of June before disappearing on the 26th.

Wed 24th June 2020...
It looks as if the signal from Cape Verde Islands reached the east of England...


D4VHF G4LOH 2m FT8 4098 km 15:03:14
G4CDN D4VHF 2m FT8 4613 km 07:42:56
D4VHF G4CDN 2m FT8 4613 km 07:40:14
D4VHF G4PIQ 2m FT8 4546 km 03:48:15

Note the distance for G4CDN... 4613kms!... on 144 MHz!

In the evening, there was an opening to Rome...


D4VHF IZ0UME 2m FT8 4521 km 18:54:14
IZ0UME D4VHF 2m FT8 4521 km 18:48:26
EA8CDG D4VHF 2m FT8 1546 km 18:45:26
D4VHF IW0FFK 2m FT8 4505 km 18:44:14

Another amazing distance... 4521kms. Tropo all the way or tropo & Sp-E?

North Europe to Cape Verde???....... Stations in North and Central Europe should be on the lookout for a Sporadic-E opening to the Iberian Peninsula over the next week. There is a good chance that signals would couple into the marine duct there off the south-west coast to travel onwards to Cape Verde.

Link... 
1) Tropo map from F5LEN

Reception video of S50B in Slovenia on 40 MHz - 22nd June 2020


Up to now, I've seen videos online of some of the beacons on the 40 MHz being heard. This is I believe the first reception video of someone actually talking on the new 8-metre band.

To put everything into context, I have generated a map as seen above.

Borut, S50B in Slovenia heard the Irish beacon near Dublin on 40.013 MHz and then went on to work Lloyd, EI7HBB in the west of Ireland on 40.680 MHz. This distance is about 1800kms.

Paul, G7PUV in the south-east of England was monitoring the band with an SDR receiver which had the ability to record everything on the band.

As the map shows, G7PUV is about 1200kms from S50B which is a typical distance for Sporadic-E on 40 MHz with a good opening. EI7HBB on the other hand is just 600kms away and well inside the skip zone of Sp-E. It might be possible for G7PUV to hear EI7HBB via Sporadic-E but it would need an intense opening.

As a result, the video from G7PUV just has the voice of S50B and EI7HBB is missing. It also has a sample of the many noises to he heard in the ISM band on 40 MHz.

Monday, June 22, 2020

Irish Amateur Radio Licence Exams - July/August 2020


Following the postponement of the exam scheduled for May, exams have now been arranged at venues in Dublin, Cork and Galway.

Dates for the next exams

Dublin:  Saturday 25th July at 2.00pm in the Maldron Hotel, Tallaght, Dublin 24. Latest date for receipt of applications is Wednesday 15th July

Cork:  Saturday 8th August at 2.00pm in the Radisson Blu Hotel, Ditchley House, Little Island, Cork. Latest date for receipt of applications is Wednesday 29th July

Galway:  Saturday 15th August at 2.00pm in the Menlo Park Hotel, Terryland, Headford Road, Galway. Latest date for receipt of applications is Wednesday 5th August

See www.irts.ie/exam for full details of these exams, including the application process and latest dates for receipt of applications.