There was a hint of the upcoming Sporadic-E season when there was a weak opening on 28 MHz on Friday 26th March 2021. It didn't amount to much though and it seemed mainly confined to Spain.
The previous day, the 25th of March was a bit unusual in that I didn't hear a single FT8 signal on 10m all day. I nearly always hear something.
As we move into early April, the Sporadic-E openings on 28 MHz should start up with maybe more regular openings later in the month.
If you're interested in the upper HF bands or any of the VHF and UHF bands then your horizon is all important. On bands like 144 MHz and above, the vast majority of signals are coming in from the horizon and just above it.
On bands like 28 MHz, 50 MHz & 70 MHz, the signals may be coming in at a slightly higher angle with Sporadic-E but they are still very close to the horizon. Whether you're operating from home or thinking or going portable then knowing your horizon can help explain what's going on.
First off, the website for checking your horizon is https://www.heywhatsthat.com/
In this post, we'll look at how to use it and some tips on getting them most out of it. To help explain it, I am going to do a profile of Paul Logan's location in Lisnaskea in Co.Fermanagh, Ireland. Paul is an avid listener to the Band 2 FM band from 88 to 108 MHz and logs hundreds of radio stations from all over Europe every year.
Getting started...
After going to the HeyWhatsThat site, click on the 'New panorama', zoom in to find your own location on the map and then click on it.
I have done this in the example above for Paul's location and them zoomed back out. On the left side of the screen, your latitude and longitude will be automatically filled in after you click on the map. You can also select the height above ground so I selected 8-metres which is the height of Paul's antenna.
Note that the site uses the general topography to calculate your horizon, it doesn't take buildings or trees into account.
Also make sure to select 'Metric' at the bottom of the screen to use proper measurements.
Then click 'Submit request'.
Using the results...
After a short while, a map is generated. I clicked on the 'Visibility cloak' to show the areas that are visible from Paul's location. The Red triangles are distant peaks and I clicked on 'Contours' to highlight the topography.
This is that the horizon looks like for Paul...
There is a large hill with an elevation of about 5 degrees to the north-east of Paul's location (45 deg bearing) and this is clearly shown on the image above. This would have a major impact on all signals at 144 MHz and above. As Paul notes himself, he finds it very difficult to get distant stations on Band 2 in that direction.
That hill would also impact on all long distance single hop Sporadic-E coming from that direction on all bands from 28 MHz to 144 MHz. Short skip arriving at a higher angles on say 28 MHz or 50 MHz would probably clear the hill.
Due east at 90 degrees, there is an interesting gap which might might allow some distant Band 2 tropo or Sporadic-E through.
From 100 to 140 is another impediment to low angle signals but it gets much better after 150 degrees or so. Paul has a very good take off at about 190 degrees towards the Canary Islands and even those distant line of sight peaks around 270 degrees are so low that there are unlikely to be much of a problem. As a result, his location will be wide open to say the USA on 28 MHz once the sunspot numbers increase.
Example 1: Poor tropo path to Scotland.
In this example, I have shown what the path is like to Scotland and how the hill is in the way. If you are trying this from your location, then just click on any location of interest and the site will show you the path and where it is on your horizon.
Example 2: Good tropo path to Spain
As can be seen from the horizon profile, Paul has a good path to the south and this can allow him to gain access to the marine duct that sometimes occurs between Ireland and Spain. The distance shown is about 1200kms which is really good for Band 2 tropo.
Example 3: Sporadic-E footprints...
Using the 'Up in the air' button, I was able to simulate what the limit for one hop Sporadic-E from Paul's location might be. One the left above is the approximate range if Paul had a completely flat horizon. The one on the right is the reality.
For Italy, the local hill restricts signals further south than Rome.
For Poland, signals from the east of the country should be easy to hear except the local hill makes things more difficult. Belarus and the west of Ukraine are also more difficult. Notice that that little gap at 90 degrees is reflected in the Sporadic-E footprint.
For the Baltic states and Finland, they should be well within Sporadic-E range but again, the local hill makes things difficult.
It's possible in many cases that some local tropo conditions will extend the footprint further east but overall, the local hills make hearing these areas more challenging.
Example 4: F2 propagation...
As the sunspots increase, there will be weak F2 openings on 28 MHz. Towards the west, Paul should have no problems reaching Newfoundland and Nova Scotia in Canada. With the help of a more southerly second hop, he is well placed to hear signals from well into the USA.
Towards the eastern Mediterranean, the local hill will block some of those signals when the band is just open. Ironically, it may actually be easier to hear signals further away in places like the Arabian peninsula once there is a second hop.
'Up in the air' Values...
Example 5: Line of sight paths...
The HeyWhatsThat site can also be used to examine line of site paths. The map above shows the path from Paul's location to Clermont Carn in Co.Louth, about 75kms away. This is a major transmitter site for Irish radio stations.
Let's say for example, Paul wanted to get a line of sight path for a contact on the microwave bands. The profile below shows the local hill in the way but there is a location 7kms away that is line of sight to Clermont Carn.
Other uses... Here's a few...
Portable operation, DX-peditions, Summits on the Air (SOTA) activations, contesting ... are there obstructions in the way? Is your 'perfect' contest location blocked at a low angle on the upper HF bands say to the USA?
In summary... This is a very useful utility to have and the more you use it, you tend to think of other uses.
For the bands like 28 MHz and 50 MHz, short skip can hide the shortcomings you may have in a certain directions. Your horizon profile should make you aware of these and you're looking for no more than 2 degrees.
For the higher bands like 70 MHz, 88 to 108 MHz, 144 MHz and above, tropo becomes a more important propagation mode. This time, you're looking for a very low horizon and the lower the better.
There's a very good reason why people put antennas up as high as possible on the VHF and UHF bands.
This is one of the VHF contacts that caught my attention during the summer last year.
On the 2nd of July 2020, HZ1SK in Saudi Arabia and K4MOG in the USA completed a successful FT8 contact on 50 MHz.
What was unusual about this contact was the fact that it was in the region of 11,460 kms. To put that into context, that is the equivalent of London to Hawaii or London to the NW of Australia.
The propagation mode was probably multi-hop Sporadic-E with at least six hops being required. While single hop or double hop Sporadic-E is reasonably common, the chances of getting six Sp-E clouds in the right spot and the correct distance apart is much lower.
The very first 6m contact between the USA and Saudi Arabia took place just a few weeks earlier when K1TOL in the state of Maine in the NE of the USA worked 7Z1SJ. The distance on that occasion was around 9933 kms which may have been five hop Sporadic-E.
Around the time of the equinox every year, there are long distance VHF contacts made across the equator by means of Trans-Equatorial Propagation (TEP).
This year is no exception and on the evening of the 22nd of March 2021 (early morning on the 23rd in terms of UTC time), the 144 MHz band was open between Brazil and the Caribbean.
The map above shows the FT8 signals heard by WP4KJJ in Puerto Rico.
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.
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...
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.
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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.
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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 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.
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.
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.
(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.)
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.
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. "
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.
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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.
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 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/
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.
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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.
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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...
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...
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...
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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...
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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.
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.
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See below...
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.
