2024 10m QRSS Challenge: - IK2JET & N8NJ 16th Feb

As part of a challenge for 2024, I've decided to see how many QRSS signals I could capture on the 28 MHz band during the year. On the 16th of February, I managed to get screen captures of IK2JET in the north of Italy and N8NJ in Ohio in the US.

1) IK2JET... At 16:17 UTC, I managed to get a successful screen capture of the QRSS signal from Alberto, IK2JET.

As can be seen from the image above, the signal wasn't too strong but it was a positive ID all the same and a new DXCC for 2024.

You can note how the QRSS signal has a slight 'fuzz' to it and is slightly distorted. It's similar to the backscatter signals from G0PKT & G0MBA which are going across the centre of the screen.

2) N8NJ... At 16:24 UTC, I got another screen capture and this time, I got a nice QRSS signal from Larry, N8NJ in Ohio.

The signal from N8NJ can be seen above at the top of the screen and it looks cleaner with less 'fuzz' than some of the other signals.

These are the WSPR decodes that I got from N8NJ during that hour and it suggests that the QRSS signal might have been in the region of -10dB.

local   y-m-d txCall txGrid rxCall rxGrid MHz W SNR drift kms  
2024-02-16 17:00 N8NJ EN81go EI7GL IO51tu 28.126084 1 -13 0 5574 
2024-02-16 16:50 N8NJ EN81go EI7GL IO51tu 28.126082 1 -5 0 5574 
2024-02-16 16:40 N8NJ EN81go EI7GL IO51tu 28.126084 1 -13 0 5574 
2024-02-16 16:30 N8NJ EN81go EI7GL IO51tu 28.126083 1 -10 0 5574 
2024-02-16 16:20 N8NJ EN81go EI7GL IO51tu 28.126084 1 -10 1 5574 
2024-02-16 16:10 N8NJ EN81go EI7GL IO51tu 28.126084 1 -7 0 5574 
2024-02-16 16:00 N8NJ EN81go EI7GL IO51tu 28.126084 1 -12 0 5574

Propagation Modes???.... What were the propagation modes responsible for these signals? I generated this propagation map below with VOACAP and the stations are marked in black.

N8NJ at 5570kms seems to be about right for two F2 layer hops and that one is easily explained.

The signal from IK2JET at 1550kms is more difficult. If it was a few more hundred kms away, I'd be more certain of one F2 hop but it seems a bit close. 

It could be Sporadic-E but we're in the middle of February and not the Summer Sp-E season. I did note plenty of other of WSPR signals on the day from the white skip zone around my location.

The signal as noted had some 'fuzz' to it which is unlike a nice clean one hop signal and that might suggest a back scatter or multi-path quality about it.

Sometimes, you just look at the evidence and it's hard to come to any firm conclusion.

In summary... That brings the QRSS tally so far for 2024 up to 12-callsigns & 7 DXCC.

1) 08 Jan 2024: VE1VDM - DXCC #1
2) 10 Jan 2024: VA1VM
3) 15th Jan 2024: G0MBA - DXCC #2
4) 15th Jan 2024: G0PKT
5) 15th Jan 2024: AE0V - DXCC #3
6) 16th Jan 2024: RD4HU - DXCC #4
7) 16th Jan 2024: W1BW
8) 17th Jan 2024: OH5KUY - DXCC #5
9) 18th Jan 2024: TF3HZ - DXCC #6
10) 6th Feb 2024: VA3RYV
11) 16th Feb 2024: IK2JET - DXCC #7
12) 16th Feb 2024: N8NJ

2024 10m QRSS Challenge: - VA3RYV 6th Feb

As part of a challenge for 2024, I've decided to see how many QRSS signals I could capture on the 28 MHz band during the year. On the 6th of February, I managed to get a good capture of VA3RYV in Ontario, Canada.

The QRSS signal of VA3RYV can be seen in the image above. It starts with a 'Slow Hell' image of the VA3RYV callsign followed by the signal in morse code. The whole sequence lasted about 6-minutes.

Wes, VA3RYV was using 100-milliwatts output power into a have-wave dipole about 15m above ground level. The path length was around 5,255kms and it's likely it was two F2 layer hops.

In summary... That brings the QRSS tally so far for 2024 up to 10-callsigns & 6 DXCC.

1) 08 Jan 2024: VE1VDM - DXCC #1
2) 10 Jan 2024: VA1VM
3) 15th Jan 2024: G0MBA - DXCC #2
4) 15th Jan 2024: G0PKT
5) 15th Jan 2024: AE0V - DXCC #3
6) 16th Jan 2024: RD4HU - DXCC #4
7) 16th Jan 2024: W1BW
8) 17th Jan 2024: OH5KUY - DXCC #5
9) 18th Jan 2024: TF3HZ - DXCC #6

10) 6th Feb 2024: VA3RYV

2024 10m QRSS Challenge: - OH5KUY 17th Jan

As part of a challenge for 2024, I've decided to see how many QRSS signals I could capture on the 28 MHz band during the year.

QRSS are very slow morse code transmissions where the dots and dashes are several seconds long and the signals are decoded by looking at a waterfall display on a screen rather than listening to the signal.

The QRSS signals are usually just below the WSPR signals on the amateur radio bands. This means it's possible to have your PC decoding WSPR signals up around 1500 Hz while you look at the QRSS signals about 500 Hz or so lower in the audio spectrum at the same time.

2024 #8 - OH5KUY... The 8th QRSS signal that I managed to capture this year was Ari, OH5KUY in Finland. Ari reports that he is running 1.5-watts into a C610 vertical antenna. His locator square is KP41DB.

The distance is from OH5KUY to my location is about 2437kms, an ideal distance for F2 layer propagation when the 28 MHz opens up to these northern latitudes.

Ari's signal was actually very strong for a QRSS signal and I had to adjust the volume settings on the radio because it was too strong compared to the rest. Most QRSS signals are buried in the noise and you get to see them only on a screen. Ari's signal by contrast was up to S4 here and it was a loud clear signal.

This is the signal in more detail. As you can see, something happened at Ari's location at about 13:52 to cause a slight rise in frequency. It's only about 4Hz but it can be seen.

That's the beauty of QRSS, you can actually 'see' the signal. You can see the frequency drift , you can see how the strength of the signal changes over time and you can see any unusual propagation effects.

With digital modes like FT8 and WSPR, you either get a decode or you didn't and if there isn't a decode, you're often not sure why. With SSB or CW, you're listening to an audio signal but it's what's happening here and now. You're missing those visual clues of QRSS which add so much more information.

The one that got away... It looks as if there was Sporadic-E on the band as well on the 17th. TF3HZ in Iceland popped out of the noise and I was all ready to get a nice screengrab but I lost it when I changed some settings on the SpectrumLab software. Lesson... screengrab first, adjustments later. Another day...

In summary... That brings the QRSS tally so far for 2024 up to 8-callsigns & 5 DXCC.

1) 08 Jan 2024: VE1VDM - DXCC #1
2) 10 Jan 2024: VA1VM
3) 15th Jan 2024: G0MBA - DXCC #2
4) 15th Jan 2024: G0PKT
5) 15th Jan 2024: AE0V - DXCC #3
6) 16th Jan 2024: RD4HU - DXCC #4
7) 16th Jan 2024: W1BW

8) 17th Jan 2024: OH5KUY - DXCC #5

2024 10m QRSS Challenge: - RD4HU & W1BW 16th Jan

As part of a challenge for 2024, I've decided to see how many QRSS signals I could capture on the 28 MHz band during the year.

QRSS are very slow morse code transmissions where the dots and dashes are several seconds long and the signals are decoded by looking at a waterfall display on a screen rather than listening to the signal.

The QRSS signals are usually just below the WSPR signals on the amateur radio bands. This means it's possible to have your PC decoding WSPR signals up around 1500 Hz while you look at the QRSS signals about 500 Hz or so lower in the audio spectrum at the same time.

2024 #6 - RD4HU... Most QRSS signals take the form of very slow morse code transmissions but sometimes, other modes are used. The screen capture above shows the slow-Hellschreiber mode which is more often referred to as "slow Hell".

RD4HU is located in the city of Samara on the Volga River in European Russia and was using 5-watts as far as I know. His signal was strong as can be seen by the clear trace.

The distance to my location on the south coast of Ireland is about 3855 kms which is ideal for one F2 layer hop, hence the strong signal.

2024 #7 - W1BW... Another method of sending a signal is as a symbol or character. This is where some degree of artistic flair comes into play.

Bruce, W1BW in Boston has a flying 'W' that he uses for QRSS. W1BW is running 200mW from a Hermes Lite 2 and the antenna is a random dipole about 25m long on the rooftop of a condominium building in the city of Boston, about 25m AGL and 2m above roof level..

W1BW is located just over 4700kms from my location and the mode of propagation was probably two hops from the F2 layer of the ionosphere.

In summary... That brings the QRSS tally so far for 2024 up to 7-callsigns & 4 DXCC.

1) 08 Jan 2024: VE1VDM - DXCC #1
2) 10 Jan 2024: VA1VM
3) 15th Jan 2024: G0MBA - DXCC #2

4) 15th Jan 2024: G0PKT

5) 15th Jan 2024: AE0V - DXCC #3

6) 16th Jan 2024: RD4HU - DXCC #4

7) 16th Jan 2024: W1BW

2024 10m QRSS Challenge: - G0PKT, G0MBA & AE0V 15th Jan

As part of a challenge for 2024, I've decided to see how many QRSS signals I could capture on the 28 MHz band during the year.

QRSS are very slow morse code transmissions where the dots and dashes are several seconds long and the signals are decoded by looking at a waterfall display on a screen rather than listening to the signal.

The QRSS signals are usually just below the WSPR signals on the amateur radio bands. This means it's possible to have your PC decoding WSPR signals up around 1500 Hz while you look at the QRSS signals about 500 Hz or so lower in the audio spectrum at the same time.

2024 #3 & #4 - G0MBA & G0PKT... The QRSS signals shown above were captured at about 10:40 UTC and it shows the QRSS trace from G0MBA and G0PKT who are 650kms to the east of my location in Essex, England. From what I know, I think both are running 0.2-watts into vertical antennas.

You'll notice that the signals have a slight 'fuzz' as opposed to a clean tone. I hear/see these two stations practically every day and I think the signals are F2 layer backscatter. If I was to try again during the Sporadic-E season during the summer, both signals would be nice and clean.

At 650kms, both signals from G0MBA & G0PKT are way too far for ground wave and too close for normal F2. The signals are probably being propagated off the F2 layer, being reflected in some distant region and then returning to my location.

2024 #5 - AE0V...In the afternoon, I got a capture of the QRSS signal of AE0V in Minnesota (EN34FU) in the USA who is about 6,000kms from my location.

Ned, AE0V reports using a solar powered transmitter with no battery storage running 100mW into a 1/4 wave stainless whip about 8m above the ground.

The signal from the USA is easily explained as it's via multi-hop F2 layer propagation. 

In summary... That brings the QRSS tally so far for 2024 up to 5-callsigns & 3 DXCC.

1) 08 Jan 2024: VE1VDM - DXCC #1
2) 10 Jan 2024: VA1VM
3) 15th Jan 2024: G0MBA - DXCC #2

4) 15th Jan 2024: G0PKT

5) 15th Jan 2024: AE0V - DXCC #3

2024 10m QRSS Challenge: - VA1VM 10th Jan

As part of a challenge for 2024, I've decided to see how many QRSS signals I could capture on the 28 MHz band during the year.

QRSS are very slow morse code transmissions where the dots and dashes are several seconds long and the signals are decoded by looking at a waterfall display on a screen rather than listening to the signal.

The QRSS signals are usually just below the WSPR signals on the amateur radio bands. This means it's possible to have your PC decoding WSPR signals up around 1500 Hz while you look at the QRSS signals about 500 Hz or so lower in the audio spectrum at the same time.

2024 #2 - VA1VM... The first signal I captured in 2024 was from Vernon, VE1VDM in Nova Scotia, Canada back on the 8th of January. This is outlined in this previous post.

Conditions on the 28 MHz band were better on the 10th of January and the 'VDM' QRSS signal was in again but stronger as can be seen above. For this beacon, Vernon was using a QrpLabs U3S with low pass-filter into a QrpLabs power amplifier delivering 1-watt on 10m. The antenna was ground mounted Hustler 6BTV vertical.

In the last 24-hours, Vernon has put a second QRSS transmitter on the air with the callsign VA1VM. You can see this as a weaker signal in the image above.

The VA1VM signal is from a 150 milliwatt transmitter into a  Hustler 10m 1/4 wave resonator mounted on a 1.37-metre long Hustler mast extender. It really is amazing that a 0.15 watt signal can make it across the Atlantic.

Both beacons are located in the town of Truro in Nova Scotia and are just a few kms apart. The antenna on my side was a simple CB type half-wave vertical.

The map above shows the location of the transmitter and receiver. The distance is about 4000kms which is ideal for 1-hop of F2 layer propagation.

Even though it's the same person, it's a second QRSS signal. That brings the QRSS tally so far for 2024 up to 2-callsigns & 1 DXCC.

08 Jan 2024: VE1VDM
10 Jan 2024: VA1VM

2024 10m QRSS Challenge: - VE1VDM 8th Jan

As part of a challenge for 2024, I've decided to see how many QRSS signals I could capture on the 28 MHz band during the year.

QRSS are very slow morse code transmissions where the dots and dashes are several seconds long and the signals are decoded by looking at a waterfall display on a screen rather than listening to the signal.

The QRSS signals are usually just below the WSPR signals on the amateur radio bands. This means it's possible to have your PC decoding WSPR signals up around 1500 Hz while you look at the QRSS signals about 500 Hz or so lower in the audio spectrum at the same time.

2024 #1 - VE1VDM... The first signal I captured in 2024 was from Vernon, VE1VDM in Nova Scotia, Canada.

Vernon was using a QrpLabs U3S with low pass-filter into a QrpLabs power amplifier delivering 1-watt on 10m. The antenna was ground mounted Hustler 6BTV vertical.

The antenna on my side was a simple CB type half-wave vertical.

The map above shows the location of the transmitter and receiver. The distance is about 4000kms which is ideal for 1-hop of F2 layer propagation.

So that's the QRSS tally so far for 2024... 1-callsign & 1 DXCC.

F2 Skip Zone on 28 MHz - 7th Dec 2023

As the WSPRnet website was down for most of today, I left the radio on the FT8 frequency of 28.074 MHz instead. As expected, there were a lot more signals on this mode.

One thing that stood out after a few hours was the skip-zone as shown in the map above. There was no sign of any real Sporadic-E and nearly all of the signals that I heard were coming off the F2 layer of the ionosphere.

The closest signals to the south-east were front central Italy around the 1700km mark. At this distance, the signals were probably coming in to my location about 25-degrees above the horizon. Anything closer than this resulted in a higher angle and propagation wasn't possible.

To the north-east, the closest stations were about 2300kms in the north of Sweden with no sign of anyone closer.

It's also interesting to note that all of Spain is missing, even the far south of the Iberian peninsula is too close for 28 MHz propagation today.

WSPR activty report for the 28 MHz band - Nov 2023

Every day for the last few months, I have left the radio listening on the WSPR frequency of 28.1246 MHz and I feed the spots up to WSPRnet. Most days, I don't even check what the radio heard, I just leave the radio on so that others can see how far their 10m WSPR transmitters are reaching.

I had a look today at what I heard for the last 5-weeks which is from the 26th of October to the 29th of November 2023. Considering that we're near the peak of the sunspot cycle, this post gives an idea of what what the band was like.

Totals & Distribution... In total, I heard about 1200 individual stations on 28 MHz during the 5-week period. This is a huge change from a few years ago when I would hear relatively few. It's not that conditions just got good but I think a lot of WSPR users came up to 28 MHz from the lower bands. 

There are a few false reports in the 1200 from strange callsigns out in the middle of nowhere but the vast majority of them are genuine.

The map above shows the distribution and it's obvious most of the WSPR activity is centred on North America and Europe. South America is surprising low and there is almost nothing from Africa outside of South Africa. There is however a good amount of activity from Australia.

DP0GVN... I heard the German Antarctic research station DP0GVN a total of 47 times during the 5-weeks. The best times seem to be in the afternoon but I heard it as early as 07:48 UTC and as late as 18:48 UTC.

Japan???... Where is everyone? I know there have been paths from Ireland to Japan on 28 MHz for people using FT8 but I heard nothing on WSPR. I checked some of the reports for some of the Australian stations and these seem to confirm that there seems to very little interest in WSPR in Japan.

North America... This is the distribution of stations in North America. For the USA, this pretty much mirrors the level of activity and population in the country. You can draw a line north from Houston, Texas and a lot of the radio amateurs are to the east of that.

From Ireland, it's pretty easy to hear the eastern half of the USA so it's nice to see all of those more difficult northerly paths to the west coast. This is especially true when I start seeing those VE6's and VE7's in the north-west.

I do have one report of hearing KL2OF in Alaska but I think it was bogus. I only heard it once, QRZ says the call has expired and the signal was only sent for one 2-minute period. 

I'm not even sure if a WSPR path is likely to Alaska from Europe considering the polar flutter on the signal at 28 MHz?

The UK on Backscatter... There are quite a number of stations in England using WSPR on 28 MHz and most of these stations shown above are about 400-700kms from my location. This is too short for single hop F2 layer and they are in my 'skip zone' according to usual propagation textbooks.

There might be some Sporadic-E in there but it's likely the vast majority are F2 layer backscatter. The 10m signal is being reflected off distant objects like mountains and ocean waves 1000's of kms away. It's certainly not aircraft scatter.

France - Où êtes-vous???... The map above shows the distribution of signals from western Europe. WSPR is popular in the Netherlands and Germany but where is all the WSPR activity from France???

It doesn't seem to be just a lack of transmitters either. There seems to be a equal shortage of people in France listening on the band and reporting.

Australia on 10m... It's always nice to see the 28 MHz WSPR signals from Australia coming through and I heard 29 VK stations in the 5-week period. For whatever reason, I didn't hear any VK7 stations from Tasmania.

As can be seen from the chart below, most of these stations are about 15,000 to 17,500 kms from my location.

Note the Signal to Noise reports (SNR). Most are these signals are buried in the noise and below what can be heard by the human ear. That's the magic of the WSPR mode.

WSPR seems to have a niche following in Australia and those guys are doing some interesting work investigating propagation paths on the 50 MHz and 144 MHz VHF bands.

Polar Stern... Nearly all of the WSPR signals are from stationary stations but a few are on the move. The map above shows my reception reports of the German polar research ship Polar Stern which uses the call DP0POL. It went through the English Channel a few weeks ago and made it's way down to South Africa.

Some days, propagation is good and I get a string of reception reports resulting in a blurred line. Some days, I heard it only a few times if t all.

Path of pico-balloon AF6IM

Pico-Balloon AF6IM... The very small balloon AF6IM was launched from California a number of weeks ago and it has gone around the world at least once. See my previous post.

The map above shows where I heard it over the last few weeks.

In summary... As a beacon mode, WSPR won't be of interest to everyone but it's nice to see a good level of interest in the mode especially on the 28 MHz band.

Just for reference, I was using a simple CB type half-wave antenna for this test so nothing special on my side.

Link...
1) The best website to check WSPR reports is http://wspr.rocks/

Backscatter on 28 MHz - 2nd Nov 2023

For well over 12-months, I have had my radio tuned to the WSPR frequency of 28.1246 MHz on the 10m band and I feed the decoded signals up to the WSPRnet website.

While I can see the WSPR signals clearly on the waterfall display, I can also see the very slow morse QRSS signals as well just a few hundred Hz below.

The image above shows the QRSS signals I could see on the 2nd of November 2023 and the locations of the stations are shown in the map at the start of the post.

The screenshot above shows a good capture of AE0V in the USA at about a distance of 6000kms. Ned, AE0V reports using a solar powered transmitter with no battery storage running 100mW into a 1/4 lamba stainless whip about 8m above the ground.

The signals from the USA and Canada are easily explained as they are via F2 layer propagation. The signals I find unusual are the ones from the England which are in the region of 500 to 650kms.

The trace from the 0.2-watt signals of G0PKT and G0MBA are there nearly all the time when the band is open. It's not F2 propagation in the usual sense as it's too close and it's not Sporadic-E.

I believe that it's backscatter just like what the military use for their over the horizon radar systems (OTHR). 

In this case, the 28 MHz band is open with F2 layer propagation and the signals from G0PKT & G0MBA are being reflected back towards my location from some distant point.

As an example of how consistent these signals are, I have decoded the WSPR signal of G0PKT about 1,000 times in the last 3-weeks. And that's a signal that's supposed to be in my 'skip zone' where it's supposed to be hard to reach.

There's nothing new about this, it's just that in this modern age of weak signal modes and waterfall displays, we can now see these very weak signals more clearly. 

If you're using FT8 on the higher HF bands and you see lots of reports from stations that about 200-600kms away then F2 backscatter is probably the reason.

Tracking the AF6IM Pico-Balloon on 28 MHz from the USA to China - Oct 2023

For the last 12-months or so, I have been being monitoring the WSPR beacon frequency of 28.1246 MHz nearly every day and uploading the reception reports to the WSPRNet site.

I noticed recently an unusual signal out in the Mid-Atlantic.. AF6IM. I thought at first it was a bogus WSPR report but then I noticed that I had heard the signal several times and it was moving!

After some checking, I discovered that the signal was actually from a Pico-Balloon with a 13-milliwatt WSPR transmitter underneath it. It was launched by Mark, AF6IM in California at the end of Sept 2023 and it has been slowly drifting eastwards since. At the time of writing on the 26th of October, it is over China.

The map above shows my reception reports of the 13mW beacon. It only operates for a few hours every day as it is solar powered and has no battery. That's why the signal is shown as small batches of signal locations in a row.

The pictured is further complicated by the fact that Mark actually had two 28 MHz Pico-Balloons in the air over the last few weeks.

The design of the WSPR transmitter is shown above and you can find more information about it HERE

The antenna for this 28-MHz transmitter is a very thin wire which is 2.54 metres long which is a quarter wave on 10m.

This photo by AF6IM shows the pico-balloon at launch. As the balloon gains altitude and the pressure reduces, the size of the balloon will get larger.

The solar cells are not shown.

Even though the original balloon looks very small, it's still able to keep a very small payload aloft at a high altitude. The chart above shows the launch of the balloon and floating along at an altitude of about 12,500m or 40,000ft. This is well into the Jet Stream and this is what is now carrying it  around the world.

The temperatures at this altitude are well below zero as can be seen in this image above. One obvious advantage in not carrying a battery other than additional weight is that there are no problems with a battery trying to survive at these low temperatures.

In conclusion... There have been plenty of other pico-balloons operating on lower frequencies in the past like on 14 MHz but I really don't have much interest in those bands. This is the first time I recall seeing one operating on 28 MHz.

What I find fascinating is that I have heard the little 13-milliwatt 28 MHz transmitter over 450 times over the last few weeks while it was hanging below a little balloon up in the Jet-Stream.

If you want to track it, you can follow it HERE

9X5RU from Rwanda worked on 28 MHz - March 2023

With the Irish V26EI expedition to Antigua now on the air, I was wondering if I could hear them? I had a look at the DX Cluster and there was no sign of them when I checked, However, I did notice that 9X5RU in Rwanda was active on CW on 28 MHz.

After a few minutes of setting up the morse key again and the various settings on the radio, I finally managed to work them after several calls.

When I wrote the contact into the logbook, I was surprised to see that my last contact on the HF bands was back in June of 2020.

It's not that I haven't been active, my radio has been decoding either FT8 or WSPR signals on 28 MHz practically every day for the last 3-years and feeding the reports up to their respective websites. It's just that I have no interest in chasing DX.

The CW contact was at 16:24 UTC on the 29th of March 2023. As can be seen from the map above, it was a 7000km north-south path and it's likely it took two F2 layer hops.

The HF propagation website Proppy predicted that my 80w signal from my half wave vertical would be above the noise in Rwanda and it looks about right.

I have no idea if Rwanda was a new country for me or not, I'm really not too bothered. I have no interest in working them on any other band or mode, I worked them on CW on 28 MHz so the box is ticked.

Using morse code is like playing a musical instruments like a guitar, if you don't practice on a regular basis then you get rusty and you get very rusty if you haven't used it in 3-years. I'll have to start using it more.

Link... 9X5RU website.

Prediction for 28 MHz propagation for 3Y0J on Bouvet Island - Feb 2023

First a disclaimer! I really don't have much interest in DX on the HF bands, DX-peditions or the HF bands in general but I have seen a lot of 'chatter' about predictions for propagation for the 3Y0J expedition on Bouvet Island during February 2023. I decided to have a look at what propagation on 28 MHz might be like and I will concentrate on Europe and North America.

If you want to see a video about general HF propagation then have a look at this previous post with a video from OH6BG.

Bouvet Island is a small island in the South Atlantic. The 3Y0J team plan to operate from a location 80m above sea level at Cape Fie at the south-east tip of the island.

The one thing to take away from this image is that there are mountains that are about 600-700m high about 4-5 kms from the 3Y0J site and these will impact the signal on the 10m band. It might be fine for the lower HF bands like 40-17m where there may be much higher level angles of radiation involved for propagation but the mountains will block some of the low angle signals required for 28 MHz. This is especially true for North America. More on that later.

This is the Great Circle map for Bouvet Island. Starting from the west... 270 degrees...and going clockwise.

North and South America are to the north-west and in the direction of the mountains... not great.

Europe to the north is blocked somewhat but is much better than North America. Japan has a sea path. Australia also has a sea path and it's likely that VK6's in Perth will fare better than their VK2,3 & 4 colleagues. The required path for some place like Sydney requires the signal to travel further south and there may be no propagation on the higher HF bands. New Zealand is at the other side of the Antarctic so that will be a challenge.

3Y0J Horizon... I put together a very rough horizon plot for the 3Y0J site on Bouvet Island and it's shown above. Note that the vertical scale is exaggerated for clarity.

A - 268 deg - This is the direction of Los Angeles and Buenos Aires. For low angle signals on 28 MHz, they fare better than the rest of the Americas. Los Angeles is a challenge from a distance point of view whereas stations in South America have a lot fewer hops to contend with

B - 282 deg - Houston. The mountains will block anything below 6.5 degrees on 28 MHz which is significant.

C- 291 deg - Florida and Sao Paulo. A 6 degree obstruction.

D - 305 deg - New York. About 6.5 degrees.

E - 323 deg - Newfoundland. Starting to get a bit easier but still a 5 degree obstruction.

F - 350 deg - Lisbon. Now down to just under 4 degrees. Better but still not great.

G - 357 deg - London. About 3.5 degrees. I have a local hill here which is about this level. I can hear stations on 28 MHz coming in from that direction but the performance is a lot worse compared to  someone who doesn't have this obstruction 

H - 6 deg - Berlin. Just below 3 degrees.

I - 11 deg - Warsaw. Down to 2 degrees. Getting down to a level where I'd start considering it being not too much of an obstruction on 28 MHz.

28 MHz Predictions - Feb 2023... For the 10m predictions, I used 100-watts from a CW station ...a typical signal for an average station and not someone with beams, towers and amplifiers. 3Y0J will of course be using much more than this but these are the kind of signals they will be listening for. 

10:00 UTC : Band is just getting going with a modest signal into Europe. The first F2 hop puts a big signal into South Africa. You can see the second F2 hop over the centre of Africa. Note that places like Greece and Sicily are in a bit of a skip zone.

12:00 UTC : The propagation moves further west. The 4th F2 hop improves signals across the centre of Europe. Note again that skip zone between the 3rd and 4th hops in the south of Europe. The path just opens to the the east coast of the USA.

16:00 UTC: The one thing to note here is the sun setting in the east of Europe. This creates a peak in signals at 28 MHz as it passes. It's a bit like a surfer waiting to catch that big wave. What's good about this is that it is confined to a relatively small geographic area.

For example, a station in Warsaw at sunset should see a peak in signals and is competing in the pile up with stations in the east of Europe as opposed to all of Europe.

There are signals in the south of Europe but it's still in a bit of a skip zone. Most of the USA is now covered.

18:00 UTC : The sunset peak reaches western Europe. It's also the best time for stations in southern Europe but there's plenty of competition from stations to the north. Signals are improving in North America.

20:00 UTC : The propagation reaches North America but the sun also starts setting in Bouvet. The one thing to notice here is that there will be skip zones. The signal could be reasonable in New York and weak in Chicago.

Caveats... It should also be noted that this is just a prediction! 

The 3Y0J team is there for most of February and the sunrise and sunset times will change a good bit over that period.

The predictions above are based on a station on a flat site with a flat horizon. The mountains and hills will block the low angle signals in certain directions and the more northern parts of where the peaks are shown are likely to be missing.

Top Tip!... Regardless of what band you're on, look for sunrise and sunset times for Bouvet and your own location, This is especially true for stations in Europe and North America. 

As the sun sets, the layers in the ionosphere can get tilted and a high angle signal going over those obstructions on the horizon can get turned into a low angle signal to be propagated forward.

Bottom Line... If you're in North America and on any of the bands from 30m to 10m then look at the sunset time in Bouvet.

Link...
1) Try out the Proppy prediction page HERE.