Showing posts with label F2. Show all posts
Showing posts with label F2. Show all posts

Wednesday, November 29, 2023

F2 opening on the 50 MHz band across the North Atlantic - 27th Nov 2023


As we approach the peak of the solar cycle, things are beginning to improve on the 50 MHz (6m) band with some F2 layer propagation appearing.

In general, north - south openings are the first to occur on the 6m band as the conditions improve in the F2 layer of the ionosphere. You'll see reports of openings from the Europe to South Africa and from North America to South America. Nice openings but nothing to get too excited about.

The openings to watch out for are the east-west ones from more northerly latitudes. These paths are much more difficult so it was interesting to see an opening on the 27th of November 2023 from the north-west of Europe to North America.


The image above shows the FT8 paths for EI7BMB near Dublin and it's an example of what the opening was like. It's likely that the path from Ireland to Newfoundland was the only single F2 hop. All of the other longer paths required at least two hops.

The most westerly station was W5LDA in Oklohoma.


The image above shows the 6m paths for K1TOL in the state of Maine. The most interesting paths here are the most northerly ones with an opening to the north of Denmark and the south of Sweden.

The solar flux on the day was 187. This isn't going to be a one-off and there should be plenty more east-west openings on the 50 MHz band across the North Atlantic over the next few weeks. Check around 13:00 to 16:00 UTC.

It'll be interesting to see over the next few weeks if there are any openings from the west coast of the USA to the north of Europe.

Tuesday, January 17, 2023

Opening on the 50 MHz band between Europe and Australia - 16th Jan 2023

 

On the 16th of January 2023, there was an opening on the 50 MHz band between Australia and Europe. Tom, SP5XMU supplied the screenshot above which suggests that there was plenty of activity.

I had a closer look at this opening and what I present below is an overview of what it was like. It's not an extensive list of all the contacts or paths but I feel it gives a good representation.

While the image above suggests an extensive opening, it would seem that the footprint of the opening in Europe and Australia was confined to certain geographical areas.


The map above shows the FT8 paths from VK6KXW in the west of Australia. The number of European stations is quite low and the main footprint is in Portugal, Spain and the west of France.


VK6IR is also in the west of Australia and the image above shows the FT8 paths in Europe. Again, it's a relatively small geographic area in Europe. Notice how the F2 signals seemed to have jumped over Italy and Greece.


The image above shows the 6m paths from VK5BC near Adelaide. Note the little cluster of signals from the west of France.


This image shows the paths from VK3WK near Melbourne. Same pattern again. From what I can tell, the stations near Sydney and the VK4 stations further up the coast near Brisbane were not able to access this particular opening.

The longest path that I saw was 17,875kms between CT1IUA in Portugal and VK3DUT in the SE of Australia.

These are the spots from the DX cluster which seems to concur with the observations above...

de dx freq obs time
VK6KXW  EA7KLL 50313  [LoTW] FT8 -20 dB 1220 Hz 1033z 16 Jan
VK3OTR  F4BKV 50314.5  [LoTW] FT8 QF02WH19<>IN96GG Tnx call ft8 1010z 16 Jan
VK3OTR  F1IXQ 50314.5  [LoTW] FT8 QF02WH19<>IN95PP Tnx qso 1009z 16 Jan
VK6FLVV  EC4TR 50313  [LoTW] 1006z 16 Jan
VK6KXW  EC4TR 50313  [LoTW] tu qso 1000z 16 Jan
VK6KXW  EC4TR 50313  [LoTW] FT8 -17 dB 545 Hz 0948z 16 Jan
VK6KXW  EA3CA 50313  [LoTW] FT8 -14 dB 1601 Hz 0947z 16 Jan
VK6KXW  9H1TX 50313  [LoTW] wkd, vk3/5/6 tu david 0921z 16 Jan
VK5PO  F4BKV 50313  [LoTW] 200w res dipole at15ft 0915z 16 Jan
VK6KXW  9H1TX 50313  [LoTW] FT8 -17 dB 716 Hz 0900z 16 Jan
VK6KXW  9H1TX 50313  [LoTW] FT8 -7 dB 714 Hz 0835z 16 Jan
EA7HG  VK6KXW 50313  [LoTW] FT8 -19 dB 672 Hz 1021z 16 Jan
EA5WU  VK3KJ 50314  [LoTW] FT8 IM99WU<>QF21 0954z 16 Jan
EA5WU  VK3FZ 50313  [LoTW] FT8 IM99WU<>QF22 0952z 16 Jan
9H1TX  VK5AKK 50313.7  JM75FU<F2>PF94HK FT8 0920z 16 Jan
9H1TX  VK3GA 50313.7  [LoTW] JM75FU<F2>QF22 FT8 0914z 16 Jan
9H1TX  VK3FZ 50313.7  [LoTW] JM75FU<F2>QF22 FT8 0913z 16 Jan
9H1TX  VK5BC 50313.7  [LoTW] JM75FU<F2>PF85 FT8 0906z 16 Jan
9H1TX  VK6KXW 50313.7  [LoTW] JM75FU<F2>OF87 FT8 0904z 16 Jan
9H1TX  VK3BD 50313  [LoTW] CQ SECOND ALL WAY GL 0900z 16 Jan
9H1TX  VK3BD 50313.7  [LoTW] JM75FU<F2>QF22 FT8 0857z 16 Jan

All the activity seems to have been FT8 on 50.313 MHz.

Analysis... Over the last few years, we've seen some multi-hop Sporadic-E or something similar during the months of June and July. In this case, it would seem to have been a genuine F2 layer opening on 50 MHz with the solar flux up over 230.

As we get closer to the equinox, I suspect we might see more 6m openings like this. The question is if they will reach further north in Europe and further south to the likes of Tasmania and New Zealand?

The huge difference with this solar cycle is that there are a lot more people using a weak signal mode like FT8 on one frequency i.e. if there is any sort of opening, the signal will be heard and reported.

That may bring it's own problems if the opening is too good though with everyone on the same frequency.

Australia to Europe FT8 paths as reported by PSK Reporter.

Thursday, November 22, 2018

Calendar for F2 openings on the 11m and 10m bands

For anyone using the 27 MHz to 29 MHz part of the spectrum, propagation is an important subject especially if you want to get work stations around the world. In general, the two main modes of propagation for the 11m and 10m bands are Sporadic-E mainly during the Summer months and F2 for the rest of the year.

In this post, the charts deal just with F2 and what parts of the world are likely to be heard at certain times of the day throughout the year.

It should be noted that this is a general guide. It is highly dependent on where we are in the 11 year Solar Cycle and what the Solar flux is. Usually for stations in North-West Europe, the Solar flux needs to be about 80 or above to start getting openings. North-South paths are more likely and the East-West ones appear with higher flux levels.

The big variable in this is Sporadic-E. This occurs mainly during the Summer months but is present during most months to a certain degree. This can allow stations in the UK for example to get into the Mediterranean on Sporadic-E and then via F2 into South Africa. Expect the unexpected on 10 metres.

This map shows various parts of the World numbered and the charts are based on propagation from the UK and Ireland.


The charts below show the times of day those are might be heard at various time of the year.


Saturday, June 4, 2011

Australia on 28 MHz this morning...

This one was a bit of a suprise! I had WSPR running on 28 MHz this morning and I was hearing some signals via Sporadic-E from Germany and Denmark.


Then I heard VK2KRR 3 times...all in the space of about 10 minutes. A quick check shows the distance to be 17,333 kms. If I worked it out correctly, then I think local sunset there was at roughly 06:58 UTC? So, the signals I heard from VK2KRR were about 10-20 minutes after his sunset.

It's likely that the F2 layer to the NW of VK2KRR became tilted after his sunset and turned his 'high' angle signal into a very low angle one.....hence the enhancement. After that it may have gone through several hops or become a chordal hop signal. I have often seen this before but it's interesting to see it displayed so well on screen.

These are the European stations that heard VK2KRR. The last leg of the journey to me was probably via Sporadic-E from central Europe. Notice that I was hearing a station in Denmark earlier and OZ7IT was hearing VK2KRR.

His signal seemed to have hopped over all the stations listening in the UK.

Friday, June 26, 2009

New Prediction for Sunspot Cycle 24...

Reading through some recent e-mails, I came accross this...

NASA Releases New Predictions for Solar Cycle 24......An international panel of experts -- led by the National Oceanic andAtmospheric Administration (NOAA) and sponsored by NASA -- has released a new prediction for the next solar cycle: Solar Cycle 24 will peak in May 2013 with a below-average number of sunspots. "If our prediction is correct, Solar Cycle 24 will have a peak sunspot number of 90, the lowest of any cycle since 1928 when Solar Cycle 16 peaked at 78,". This report clarifies a NOAA report from earlier this month that stated that Solar Cycle 24 would bring "90 sunspots per day on average."


Looking at the date, they are predicting the peak to be between 80 and 100 sunspots per month at the peak. So what does this mean? Let's compare it to previous cycles...

It looks as if it will be similiar but slightly lower than the peak of 1968/9 but worse than the last 3 peaks. What does this mean in practical terms?

In reality, near the sunspot maximum, the HF bands (14 MHz to 28 MHz) will be hopping and there will be worldwide dx regardless of how bad it turns out to be. The big issue is what will propogation on 50 MHz be like?

I remember reading before that the peak of 1968 was supposed to be pretty poor for DX on 6 metres with slim pickings via F2. If it turns out as predicted, I'd expect that there will be plenty of F2 type openings North-South from say Europe to Africa and South America. The big problem is will the MUF get high enough to support East-West type openings from say Europe to North America?....or Europe to the Far East? Stations in Southern Europe will probably work loads (EA/CT/I/etc) but what about those above 50 deg North?