Showing posts with label long path. Show all posts
Showing posts with label long path. Show all posts

Thursday, March 28, 2024

Long path opening on 28 MHz from Ireland to Australia - March 2024


Conditions on the 28 MHz band over the last few weeks have been excellent and using the WSPR beacon mode, I have heard 20 stations in Australia on the 10m band.

I usually hear these signals via short path during the morning time or early afternoon but when I checked, I noticed that I had heard two Australian stations via long path as well.

   local   y-m-d txCall txGrid rxCall rxGrid MHz W SNR drift kms
2024-03-21 08:44 VK4TDI QG62lm EI7GL IO51tu 28.126131 5 -24 0 16889
2024-03-21 08:38 VK4TDI QG62lm EI7GL IO51tu 28.126132 5 -23 0 16889
2024-03-20 20:38 VK4TDI QG62lm EI7GL IO51tu 28.126128 5 -21 0 23111
2024-03-20 08:58 VK4TDI QG62lm EI7GL IO51tu 28.126132 5 -24 0 16889
2024-03-19 13:38 VK4TDI QG62lm EI7GL IO51tu 28.126124 5 -21 0 16889

2024-03-21 08:36 VK2KYB QF56lf EI7GL IO51tu 28.126117 5 -25 0 17410
2024-03-21 08:10 VK2KYB QF56lf EI7GL IO51tu 28.126116 5 -27 0 17410
2024-03-20 20:56 VK2KYB QF56lf EI7GL IO51tu 28.126115 5 -24 0 22590
2024-03-17 07:10 VK2KYB QF56lf EI7GL IO51tu 28.126117 5 -27 0 17410
2024-02-25 08:12 VK2KYB QF56lf EI7GL IO51tu 28.126072 5 -26 0 17410

The WSPR decodes for VK2KYB in Sydney and VK4TDI are shown above. All of the short path decodes are in black while the long path decodes are in red.

The chart below shows the predicted propagation from my location on 28 MHz to the SE coast of Australia and it seems reasonably accurate. You can see the stronger short path in the morning with a modest long path in the evening.


The long path to Australia is a difficult one for me as there is a local hill here which means that the signals have to be over 3-degrees above the horizon to reach me.

Sunday, October 22, 2023

27,300km Long path opening on the 50 MHz band from Italy to Hawaii - 16th Oct 2023

Now that we have reached October and at this stage in the solar cycle, the 50 MHz band is starting to open up with some remarkable paths. This is especially true for stations in the south of Europe.


Riccardo, IZ5BRW in Italy reports a very interesting long path opening on the 50 MHz band on the 16th of October 2023 to Hawaii, a path of about 27,300kms.

IZ5BRW writes... "The opening occurred mainly on Monday 16th Oct. (09 to 11 UTC +/-) and on Tuesday 17th. (8 to 10:30 UTC +/-).

I only worked KH6HI on Monday 16th. There were also other friends able to work the KH6 stations here in Zone 5 – Tuscany.


Tuesday was stronger even though I was not at home to work KH6. My friend Steve IK5MEJ worked 3 different stations on Tuesday 17th., KH6HI – KH6WI – NH6Y.

Anyway, all qsos made in FT8 and Long Path, which is more or less 170° from my qth JN53OP. My setup is FT-5000 + 7L Yagi EF0607X home made + 500W.


It’s a 27,000Km+ path and for me, KH6 was a new one on 6m as well as a new grid and new WAZ!

Albert, KH6HI has already confirmed the qso on LOTW."

Thanks to Riccardo for the report.

Comment & Analysis... As can be seen from the screenshot above, the contact was made with FT8 and the signals were in the region of -9 to -13dB. This is just about audible to the human ear and it would be difficult to have a CW QSO at this signal level. Obviously, those signal levels are not a problem with FT8.

No doubt there were others who made similar long path contacts like this on the day but this one is a good example of what the opening was like and that others should be looking for this path as well. Note the time and beam heading.

As for the mode of propagation, it was probably multi-hop or chordal hop F2-layer.

Sunset in Hawaii was about 18:00 local time or 10:00 UTC. It's no great surprise that the opening was about 30 mins after sunset and the F2 layer would have tilted at this stage to the west of Hawaii. This allows propagation of higher frequency signals and at a lower angle.

The takeaway message from this is to look at the sunset for a region you're interested in working and try beaming long path to see if an opening is possible. 

Links... 1) See my 50 MHz page for examples of other long distance openings on the 6m band.

Wednesday, March 8, 2023

30,000km Long Path opening on the 50 MHz band between Europe and Japan - 7th & 8th March 2023


After a decline in solar flux at the end of February, there has been a marked bounce in conditions in early March with the solar flux going back up to around the 180 mark.

Late on the 7th of March 2023, there was a very good long path opening on the 50 MHz band from the south of Europe to Japan.

José, CT1BOH reported the long path opening to Japan on Twitter and looking at the PSK Reporter website, one of the longest paths was to JR4ABB which is around 29,000kms. The path is shown above and the key thing to note is how far to the south the path travels.

The reality is that there were a lot of paths on FT8 between stations in the south-west of Europe and stations in the south-west of Japan. It's not really feasible to list them all and I don't think it would anything of value, the key point is that there was a long path opening on the 6m band.

However, we can look at the specific example of CT1BOH and JR4ABB in more detail.


The map above shows the Japanese stations that reported CT1BOH or were reported by CT1BOH. You'll notice that they are clustered in the south-west of Japan. The long path signals are coming in from the south-east and JR4ABB is one of the furthest away.

A list of the Japanese stations are listed at the end of the post. The opening lasted an hour.

There are two points here...

1) The further north a station is in Japan then the maximum usable frequency (MUF) is lower and may not reach 50 MHz. 

2) The further to the north-east a station is in Japan, the further south the long path travels and the closer it gets to Antarctica and a more difficult path.


This image above shows the stations in Europe that reported JR4ABB or were reported by JR4ABB. In this scenario, the long path signals from Japan are coming in from the south-west. 

You'll notice that it was an opening that favoured the south of Europe, again the MUF is better in the south of Europe. Note that there was also a long path opening to I8IGS in the south of Italy, a distance of about 30,000kms.

For a long path opening to Japan, it gets harder the further to the north-west you go in Europe. It's likely that EA5 and EA6 stations in the SE of Spain had a distinct advantage over their EA1 compatriots in the NW of Spain even though the long path distance was similar.

In conclusion... It's remarkable to see long path signals not only reach as high as the 50 MHz band but to travel around 30,000kms as well. It will be interesting to see if there are any long path 6m reports from stations further north.

Link... For other examples of long distance paths on the 6m band, see my 50 MHz page.

1) A list of Japanese stations reporting or being reported by CT1BOH

Sunday, January 29, 2023

Long path opening on the 50 MHz band between Germany and New Zealand - 28th Jan 2023


In a previous post, I reported on how there was a short path opening on the 50 MHz band between Germany and New Zealand on the 25th of January 2023. What's better than a short path opening? A long path opening of course!

On the 28th of January 2023, there was an amazing long path opening between Europe and New Zealand on the 50 MHz band. More specifically, DK1MAX in Germany managed to complete a FT8 contact with ZL1SG in New Zealand.

DX-Cluster spots...
Spotter Freq. DX Time Info Country
ZL1RS 50323.0 DK1MAX 20:18 28 Jan RF64<>JN58 long path Fed. Rep. of Germany
ZL1SG-@ 50323.0 DK1MAX 20:10 28 Jan FT8 -9 Tnx Max great qso Fed. Rep. of Germany

On the PSK Reporter website, I found three European and two New Zealand stations that were involved in this long path opening. I have put in the approximate long path distances and I have recorded the signal reports that appeared on the site as well.

Txmtr Rcvr Band Mode Distance Time (UTC) Approx Signals
IV3KKW ZL1SG 6m FT8 ~22,000 km 20:23:11 -18dB
DK1MAX ZL1SG 6m FT8 ~22,100 km 20:20:41 -19dB
OE5OLL ZL1SG 6m FT8 ~22,200 km 19:40:41 -15dB

Txmtr Rcvr Band Mode Distance Time (UTC)
IV3KKW ZL1RS 6m FT8 22,000 km 20:27:13 -16dB
DK1MAX ZL1RS 6m FT8 22,100 km 20:03:43 -13dB

Analysis... Let's have a look at what happened. First of all the location of the stations which is important.

ZL1LG and ZL1RS have the same locator square and are located at the far north of New Zealand.


The three European stations are in roughly the same geographic location and are only about 200-300kms apart.

Opening... At the time of the long path opening, there was a path on 50 MHz between ZL1SG and South America.


At the same time, there was an opening from DK1MAX to South America.


It looks as if the two openings coupled into each other and allowed a long path at 50 MHz opening between the far north of New Zealand and a small area in Europe.

I need to stress that the location of the stations had a huge bearing on the opening. Because New Zealand is effectively on the other side of the planet from Europe, the beam heading changes drastically with a small change in location.

The geometry of the path from say the north of Germany is very different than the south of Germany. From the UK, the long path to New Zealand goes almost directly south and over the Antarctic which makes a 50 MHz path highly unlikely.

By contrast, stations to the south of DK1MAX have the possibility of long paths that are closer to the equator and more likely.

Mode of Propagation... The solar flux on the day was in the region of 150-160 but this was after coming down off a peak of around 230 about a week earlier. The path was almost certainly F2 with possibly some chordal hop involved. There may have been some TEP from Europe to South America.

In conclusion... The signals were weak for this long path opening as they were down around -13 to -19dB. If it wasn't for FT8, the opening would have gone unnoticed. It was an amazing opening and there are no doubt plenty more to come. 

Link...
1) I have put links to posts about previous long distance 6m openings up on my 50 MHz page.

Addendum: Max, DK1MAX reports... "That's a screenshot from and after the QSO with ZL1RS. We worked on 50323 as 313 was way too busy with strong EU transmitting 2nd period. Still very much excited. Thanks for the summary in the EI7GL blogspot."


Javier, LU5FF in Argentina reports paths on 50 MHz to the following stations in New Zealand...


Pipe, CE3SAD reports that during the same opening, CE6TK in Chile worked 16 ZL stations in New Zealand. In the CE3 zone of Chile, there was only one.



CE3SAD also recounts a previous long path opening way back on the 21st of April 2001. Operating as CE3SAD/2 from FF48 locator square, he managed to complete some long path contacts with VK4 stations in Australia while beaming towards Europe. The stations were located in the QH30 and QG39 locator squares and the long path distance was in the region of 27,000kms.

CE3SAD did try beaming the more direct short path to Australia but the stations disappeared. It's worth remembering that back in 2001, the dominant modes were SSB and CW and the signals had to be above or at the noise level. It's a huge difference from now when FT8 allows contacts to be made from signals that are buried in the noise.

Tuesday, December 27, 2022

Long Path Propagation on the 17m HF band - Dec 2022

Larry, VO1FOG in Newfoundland, Canada has been carrying out a number of long path propagation experiments on the HF bands recently and I found this one especially interesting. For the purpose of clarity, I'll try to give an overview of what happened so people will understand what is in the video clip further down this post.


VO1FOG is located at the eastern side of Newfoundland, Canada and on Wednesday the 21st of December 2022, he was listening to the daily morse code practice transmissions on 18.0975 MHz from W1AW in Newington, Connecticut. 

The distance from VO1FOG to W1AW at the ARRL headquarters is about 1,660kms and the direct short path signal was quite strong. However, VO1FOG was also hearing W1AW via the long path which means it nearly has to go completely around the globe. The long path is around 38,420kms.

VO1FOG was using a 3-element SteppIR antenna at 23-metres above ground level. 


The advantage of this type of antenna is that the lengths of the elements can be lengthened and shortened by motors rather than having to rotate the whole beam. This means that VO1FOG can switch from short path to long path in about six seconds.

The image below shows some morse code signals from W1AW via short path.


The dots and dashes are nice and clean and the word 'SAID' can be clearly seen.

The image below shows some morse received via the long path.


It's not the same word but you can see that it's a lot more messy with the dots and dashes coming from the short path signal mixing in with the dots and dashes coming from the long path.

The audio of the W1AW signal can be heard below. Remember that there is nothing wrong with the signal, you're just listening to the same signal arriving in Newfoundland at different times.

VO1FOG reports that the test was done at 14:50 UTC. The approximate propagation conditions for W1AW's location on 17m is shown below.


It's interesting that the long path isn't too far from the Grey Line path which is near where the sun is setting or rising.

Larry has carried out several tests like this recently and he reports that he hears both long path and short path almost daily about an hour either side of his local solar noon.

He has seen this echo effect on the 20m, 17m, 15m and 12 m bands and to a lesser extent on 10m. He did tests with K5WLT in Texas who was using 400w into an 80m dipole and the echo was seen on multiple bands on multiple days.

Larry usually does his tests by getting the other station to send the letter 'E' i.e. one-dot with a space after it. The image below shows the test with G0OVK in England when a second dot can be clearly seen.


Analysis... With the rising solar flux, a lot of people are probably hearing strange echoes on SSB and CW signals and not realise what it is. It obviously helps if the transmitting station is running high power as the long path has to travel almost around the world.

When Larry sent me the information and as I was preparing this post, I couldn't help but wonder if the signal from W1AW went around the globe for a second time? If the path is open and the signal goes around the world, does it keep going round and round the globe getting weaker and weaker each time it passes?

Is it possible to hear the second echo as the signal passes for the second time? Is it strong enough?

What about the time signal WWV on 15.000 MHz and 20.000 MHz? That produces a tick once a second, it should be possible to hear the long path tick as well. Again, is it possible to hear more than one echo in the space between ticks?

It's intriguing to think that there may be signals from high power transmitters going around the globe multiple times before finally dying out when the propagation conditions change. Again, it raises more questions... how long? Up to a second? Several seconds? Minutes? That's leads then to the subject of 'Long Delayed Echoes' which is another topic in itself.

If you have a good beam or antenna for the HF bands then have a listen and see what you can hear.

Thanks to Larry, VO1FOG for all of the background information for this post.

Wednesday, March 30, 2022

21,000km long path opening on 50 MHz between Australia & the Canary Islands - 15th March 2022


At the start of March 2022, I reported on how there was some 18,000km plus openings on the 50 MHz band between New Zealand and the Canary Islands. See previous post HERE.

About a week later on the 15th of March 2022, this distance was exceeded when there was a long path opening on 50 MHz between the east coast of Australia and the Canary Islands. The distance on this occasion was an amazing 21,100 kms!

I'm a little bit late with the post as I've been busy but it's worth highlighting that it happened. There is no shortage of long distance openings on the 50 MHz band at the moment but these tend to be mostly North-South and TEP related.

It's easy to just look at the map and so what? But remember this was at 50 MHz, a VHF band and not down on the HF bands where long path openings are pretty common.


It looks as if FT8 was used by most stations for the opening. The partial screen grab above shows the contact between EA8TL on Tenerife and VK4MA near Brisbane.

Amazingly, Jorge EA8TL was using just a Hexbeam for the contact and he was beaming towards the Caribbean.


The opening wasn't confined to just VK4MA and EA8TL. These are some of the spots from the DX-Cluster.

EA8DO 50313 VK4HJ 21:55 14 Mar 22 ft8 Australia
EA8DO 50313 VK4MA 21:43 14 Mar 22 ft8 Australia
EA8DO 50313 VK4QG 21:43 14 Mar 22 ft8 Australia
EA8TL 50313 VK4MA 21:42 14 Mar 22 ft8 Australia

Propagation Mode??? ...It's probably no accident that all stations involved in the opening were no more than 25 degrees or so from the equator. Radio propagation at these latitudes reaches much higher frequencies than for those located much further north or south.

It's highly likely that a large part of the path was due to chordal mode without the signal hitting the ground.


As for how much of the signal was due to F2? Sp-E? TEP?

Just for the record, the solar flux on the day was 110.

Saturday, March 12, 2022

Long path opening on 50 MHz between South America and Asia - 12th March 2022


12th March 2022: There seems to have been a really good opening on the 50 MHz band at about 01:00 to 04:00 from South America to the east of Asia (Thanks to N0JK on the tip off for this).

The map above from the PSK Reporter website shows the paths as reported for PY2XB in Brazil. The site shows the shortest path between two stations but I think in reality, the contacts from Brazil to Japan & Taiwan were all via long path.


Long Path V Short Path... The map above shows the situation. For someone in the south of Brazil, Taiwan is effectively the other side of the world and there isn't that much difference between short path or long path.

I'm subject to correction on this but I think this extensive opening on 50 MHz was around 21,000kms via the long path.

The map at the start of the post shows that there was a path also from Brazil to Hawaii at 01:58 UTC. The map above also shows where the daylight was at about 03:00 UTC. It was likely that there was strong TEP to the west of South America which likely played a factor in the opening.


This chart is a point to point HF propagation forecast and shows how likely an opening is on each of the bands from PY2XB in Brazil to BV3UF in Taiwan. As you can see, the long path on 28 MHz is very good from 24:00 to 06:00.

By contrast, the short path prediction is very poor at this time. The DX spots just report stations heard but no-one seems to mention short path or long path.

Propagation Mode???... As mentioned already, TEP (Trans-Equatorial Propagation) is likely to have been involved but how much? Was it partially TEP with the rest of the path via F2 propagation? Was there greyline and chordal propagation involved across the Pacific where the sun was setting?

Some seem to be very quick to explain every long distance opening as being simply TEP but remember that we're talking about a path of 21,000kms at 50 MHz. I'd suggest that it's a lot more complex than that.

Just for reference purposes, the solar flux on the day was about 127.

Notes... This was a reasonably good opening between two areas with a lot of 6m activity. The maps and data I have presented above is just a sample of this opening but it does demonstrate the distances achieved.