Wednesday 29 July 2020

New Hope For Cycle 25!

Unlike most forecasts for solar Cycle 25, a recently released paper from five solar scientists (1) has given many 6m diehards new reasons to hope!

After countless dire predictions for the upcoming cycle indicating similar or even poorer activity levels than the disappointing Cycle 24, the new paper suggests just the opposite!

In fact, the group of scientists predict that "Cycle 25 will probably be among the strongest solar cycles ever observed, and that it will almost certainly be stronger than present SC24 (116 spots) and most likely stronger than the previous cycle 23 (180 spots)." The possibility of a smoothed sunspot number (SSN) reaching as high as 305 is in the prediction!

Solar Cycle 19 was a monster, reaching a SSN level of 285 ... to imagine the possibility of something even stronger is truly exciting. The just-ending Cycle 24 was one of the weakest on record, reaching an SSN of just 116.

Will Cycle 25 replace Cycle 19 as #1? Image source with my addition in RED.

During Cycle 24, maximum usable frequencies (MUF) for F2 propagation often struggled just to reach 28MHz, and except for the peak year, the worldwide propagation conditions that amateurs had come to expect were often absent.

Should these new optimistic predictions come to pass, 6m operators can look forward to some truly, never-before-seen, fall and winter propagation ... for at least three or more winters.

With SSN values reaching the high two-hundreds or beyond, west coast operators can expect to see the 6m band often open before sunrise, most likely favoring Europe via the polar path or towards Africa via the trans-Atlantic path. Unlike 20m, there will be little to no ‘polar flutter’ and since signals propagating near the F2 MUF suffer very little path loss, they will probably be very strong.

Later in the day, propagation will shift south towards Central and South America before moving to the west. Depending on the time of year, the propagation will favor Asia, with signals from Japan, China and other far-eastern exotica in the early fall through the New Year. As well, the band will often stay open for some time after local sunset. Late winter and spring will see the western path favour signals from down under, and stretch out to the southern far east regions towards the Indian Ocean. These were the propagation patterns noted from here during Cycles 21-23, when SSNs reached 233, 214 and 180 respectively.

With much gratitude to Mark (VA7MM) for converting my old analog tapes to mp3, here is a recording I made on the morning of November 7, 1979, at the height of Cycle 21. It will give you a taste of what could be in store. On that Wednesday morning, the band opened around 0800 and continued through to sunset, closing with a three-hour opening to the Pacific and Japan. Like many other 6m operators, I had taken the day off work with a case of the 'F2 flu' that was very prevalent that winter! The recording begins with a short exchange between VE1ASJ and VE1AVX, while trying to work a very ‘rare’ (for them) KL7 ...

F2 from Cycle 21

The graph of Cycle 21 shows when the recording was made. Although not known at the time, it was very close to the peak of the cycle.



A record-busting Cycle 25 will be like these previous cycles only on steroids! With such a cycle, 10m will follow a similar pattern but will likely be open 24/7 as I recall listening to VKs and ZLs on 10m AM well after midnight during the downward climb of Cycle 19 ... and this was on a very '10m-deaf' Hallicrafters S-38 and a short wire out the attic window!

For those wanting to read the fascinating paper (Overlapping Magnetic Activity Cycles and the Sunspot Number: Forecasting Sunspot Cycle 25 Amplitude), you can find a pdf here. As well, you can read the ARRL’s own announcement of this exciting possibility here.

One certainty is, that if FT8 is still around by then, it and your soundcard will fold up quickly once the band opens with wall-to-wall S9++ signals. It may be useful during the first early minutes or during marginal openings, but knowing the signal levels that 6m F2 can produce, it will be like trying to use FT8 with dozens of new neighbors operating on your own block ... and you can easily guess how well that might work! As we’ve come to understand, FT8 is a wonderful weak-signal mode, but throw just one bone-crushing signal into the waterfall and it’s game-over ... on F2, there will be dozens of these!

Such stellar conditions on 6m are ideally suited to CW or SSB and I think there will be a fast exodus from FT8 back to the traditional modes very early ... those that aren’t prepared for this, relying only on FT8, will most likely be in for a rude awakening. If you’re a 6m “no-coder”, now’s the time to hunker-down and learn CW ... by the time Cycle 25 becomes productive, you won’t be left out of the many CW DX opportunities that will surely be available on this much quicker QSO mode.

We will no doubt be reading more about this as Cycle 25 begins to grow. As in almost all stronger than normal cycles, growth from the start to the peak is much shorter than normal so I’ll be watching for a fast rise in sunspot numbers once we are really underway.

Hindcast modelling (backtesting) of the data derived from previous cycles going back to the 1700s using the paper’s prediction methodology, shows an accurate alignment with what actually occurred. The red dots in the graph above indicate the model’s predicted peak superimposed on the actual peak. In some cases, the peaks were even higher than the modelling suggested.

The predictions identify the so-called “termination” events, landmarks marking the start and end of sunspot and magnetic activity cycles, extracting a relationship between the temporal spacing of terminators and the magnitude of sunspot cycles. The success of these predictions will depend upon an upcoming terminator event before the end of 2020. Should it occur on time, the predictions will be given a much greater chance of coming to fruition ... "with a terminator event in 2020, we deduce that sunspot cycle 25 will have a magnitude that rivals the top few since records began. This outcome would be in stark contrast to the community consensus estimate of sunspot cycle 25 magnitude."

More interesting discussions of the paper can be found here and here.

This week's high-latitude Cycle 25 sunspots are a great sign. When the terminator event occurs, solar activity will ramp-up very quickly, within one 27 day solar rotation. Let's hope we're getting close.

As noted in the paper, "Very early indications of the spot pattern are appearing at higher than average latitudes. Historically, high latitude spot emergence has been associated with the development of large amplitude sunspot cycles — only time will tell."

Hopefully we’ll all need to hold on to our hats ... it might just be the ride of our lives!

(1) Scott W. McIntosh (1), Sandra C. Chapman (2), Robert J. Leamon (3,4), Ricky Egeland (1), and Nicholas W. Watkins (2,5,6)

1 National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307, USA.
2 Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL, UK
3 University of Maryland, Department of Astronomy, College Park, MD 20742, USA.
4 NASA Goddard Space Flight Center, Code 672, Greenbelt, MD 20771, USA.
5 Centre for the Analysis of Time Series, London School of Economics and Political Science, London WC2A 2AZ, UK 

6 School of Engineering and Innovation, STEM Faculty, The Open University, Milton Keynes, UK

Saturday 18 July 2020

Hunting For NDBs In CLE258 - Pick Five!

Next weekend's CLE is something a little different. Listeners are asked to pick five frequencies only, to listen on, and then find as many beacons as they can!

During these stressful times, CLE258 might provide some much needed distraction for you.

I'm sure most listeners will find their own strategy for picking their five frequencies. Will it be the five that have given you the most loggings? The five that have provided the most loggings in North America or Europe? Will it be the five that are not being bothered by your stronger pest signals? Choose wisely and enjoy the challenge.

'CLE's are 'Co-ordinated Listening Events, and NDB DXers around the world focus their listening time on one small slice of the NDB spectrum.

From CLE coordinator Brian Keyte (G3SIA), comes the following CLE info:

Hello all
Here are the final details for this weekend’s unusual Coordinated Listening Event. 
We are each invited to choose, for our own listening, FIVE PRECISE FREQUENCY SETTINGS in the NDB range.  
     Days:    Friday 24 July - Monday 27 July
     Times:   Start and End at midday, your LOCAL time
     Target:   NDBs (including any UNIDs) heard using your choice of any FIVE frequency settings at least 10 kHz apart in the range 190–1740 kHz
For each of your chosen frequencies, use of a wide filter, or no filtering, will allow you to hear the NDBs within a few kHz on either side.  The signals will depend on the time of day and the aerial(s) that you are using, etc.   You could choose a frequency setting like 345.6 kHz if you wanted (i.e. you are not limited to whole kHz).
What frequencies would be good ones for hearing several NDBs in your own situation? 
Many of us away from Europe will find this more of a challenge, though if you are in the Southern Hemisphere your mid-winter conditions should help.
It will add extra interest for everyone if, before the CLE, you could say in an email to the List the five frequencies that you hope to use.  (In the Results we shall probably flag where listeners were using pre-selected frequencies).  Of course your choice of a frequency will not stop any other listeners from using it too!  Each of your five frequency settings should remain exactly the same throughout the Event.
Please send your final CLE log (before Wednesday) to the List, if possible as a plain text email and not in an attachment, showing 'CLE258' and 'FINAL' in its title.
Please include with every one of your loggings:
    #  The date (or just the day 'dd') and UTC (days change at 00:00 UTC).
    #  kHz - the beacon's nominal frequency.
    #  The Call Ident.
It is important to show those main items FIRST - any other optional details such as Location, Distance, etc. go LATER in the same line.
You could show the loggings in frequency order, with the receiver’s frequency setting on a separate line before each of the five groups of loggings. 
Don't forget to give your OWN location and details of your receiver and aerial(s), etc.
If you have a very basic receiver such as a ‘1AD’ and probably home made, you will know that its wide bandwidth often receives several signals at the same time.  That might be a good candidate to use for listening on one or more of your frequencies.  However, be aware that aerial changes and adjustments can alter its tuning very significantly.  To correct for that, try to use a reference NDB, ‘mid-distance from you’ so that it is audible all the time and keep it tuned to a low audio note so that the actual central receiving frequency doesn’t alter (or use an external signal generator set to the chosen frequency). 
Please make sure that any waterfall facility on the receiver is not being displayed.
If you have advanced recording facilities you COULD of course record everything during the CLE and do no live listening. However, please bear in mind that we should each stick to the five frequencies that we’ve selected in advance. While playing back recordings, the receiver’s frequency should always be set to one of your five pre-selected frequencies and not be changed to enhance a possibly difficult-to-hear signal.

Good listening!
  Brian and Joachim
From:          Brian Keyte G3SIA        ndbcle'at'
Location:     Surrey,  SE England       (CLE coordinator)


If you wish you could use any one remote receiver for your loggings,
stating the location and owner - and with their permission if required.

A remote listener may NOT also use another receiver, local or remote,
to make further loggings for the same CLE.


These listening events serve several purposes. They:
  • determine, worldwide, which beacons are actually in service and on-the-air so the online database can be kept up-to-date
  • determine, worldwide, which beacons are out-of-service or have gone silent since the last CLE covering this range
  • will indicate the state of propagation conditions at the various participant locations
  • will give you an indication of how well your LF/MF receiving system is working
  • give participants a fun yet challenging activity to keep their listening skills honed
Final details can be found at the NDB List website, and worldwide results, for every participant, will be posted there a few days after the event.

The NDB List Group is a great place to learn more about the 'Art of NDB DXing' or to meet other listeners in your region. There is a lot of good information available there and new members are always very welcome. As well, you can follow the results of other CLE participants from night to night as propagation is always an active topic of discussion.

You need not be an NDB List member to participate in the CLEs and all reports, no matter how small, are of much value to the organizers. 

Remember - 'First-time' logs are always VERY welcome!

Reports may be sent to the NDB List Group or e-mailed to CLE co-ordinator, Brian Keyte (G3SIA), whose address appears above. If you are a member of the group, all final results will also be e-mailed and posted there.

Please ... give the CLE a try ... then let us know what NDB's can be heard from your location! Your report can then be added to the worldwide database to help keep it up-to-date.

Have fun and good hunting!

Saturday 11 July 2020

NEOPHYTE Adventures

I've just added a new page to my website, The VE7SL Radio Notebook, that describes my NEOPHYTE 1 regenerative receiver spring construction project. The new page can be found here.

Like most simple regens, its performance far exceeds its simple circuit expectations. My listening adventures with it continue during The Radio Board's annual Homebrew DX Contest which runs from July 11 - 24th. You may want to give it a try, after of course, you've checked-out my new web page!