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Current propagation conditions (Some light at the End of the Tunnel?)

As The previous thread with a similar name closed at it hit 500 entries (just before it would have hit 30,000 views), I have opened a new thread as I feel this is useful for keeping an eye on what people think conditions are doing…

73 Ed.

With the rapid approach of the sunspot minimum I suspect the light at the end of the tunnel is a train entering it!:disappointed:

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Correct - see picture in my first post!

Ah! Now you’ve told me, I can see what it is!:grinning:

Should’ve gone to Specsavers Brian!

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Wouldn’t it be better to give the topic a title more relevant to the discussion (“this is useful for keeping an eye on what people think conditions are doing”) - so something like “Current propagation conditions”, or similar?

I’ve always found the “Light at the end…” title to be a tad confusing, although that’s possibly just my old head complaining :confounded:

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I’ve always found the “Light at the end…” title to be a tad confusing,

I think you’re right, Rob. There’s likely gonna be no light at the end of the tunnel before 2021. Let’s see how many threads we’ll create up to then.


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We could even set up an award scheme, and in 2022 give trophies and certificates to those who guessed closest to the correct number of threads. It could be prove to be popular, since we SOTAists just love points and awards… :smile:

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Do you mean threads or posts? Hmm, challenge to create 500 replies (posts) in this thread before the end of 2017 and get the thread auto-closed (only 491 to go)…

In any case, there are some space weather people who are saying that as we hit or approached an SFI of 64 (I think it was 64, perhaps 66) last week, that MUST be the bottom of the cycle as it has never gone below that - that would mean this cycle is almost finished. I believe a couple of months ago, the first of the next cycle were already detected. I beleive there was some rotational data about the sunspots that meant they didn’t belong to this cycle. (I could have got that totally wrong however).


Threads - i.e. the number of cycles of threads in a series reaching the reflector limit.

It has never before been measured to go below that, which is not the same as saying that it cannot go below that. Which would mean that the cycle MAY be almost finished. But who’s to say we’re not heading for another Maunder minimum, or some other solar cycle which we’ve never yet had the chance to follow with instruments.

It was a high latitude pair of spots with reversed magnetic polarity indicating that they were precursors of cycle 25. Looking at butterfly diagrams for previous solar cycles it appears that there is about a two year overlap between the first spots of the new cycle and the last spots of the old cycle, so probably the forecast date for sunspot minimum is about right (sigh!)


Oh well, we can only work with what we have.

I wonder what will happen when conditions get better though - we’ll all have the best antennas we can manage / afford. ditto best receivers and communications modes.

When conditions improve we’ll probably hear every single amateur who is transmitting on the planet - which will make the bands unusable as it will just be noise!

Can’t win - I wonder if in 5 years, we’ll be saying - wish it was 2017 again, when there was room on the bands to be able to transmit.


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Here’s an interesting article https://phys.org/news/2017-11-solar-minimum-surprisingly-constant.html reporting observations of solar microwave emissions taken over some 60 years, at 1, 2, 3.75 and 9.4 GHz, and which indicate that

the microwaves coming from the sun at the minimums of the past five solar cycles have been the same each time, despite large differences in the maximums of the cycles

which is surprising, to say the least.

Surprising perhaps. More interesting to me is how they stop the dish feed from bursting into flames when they track the sun.

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They do the measurements at night. That’s why the figures are consistent.



Perhaps it is one of those dishes surfaced with mesh rather than solid metal?

Perhaps not - the sun is fairly uniform at minimum, contrasting with its variability at maximum, so I would be more surprised if there were differences between minima.

Thanks, Andy - the keyboard is working again now I’ve cleaned the tea off it!:grinning:

Merci. I do my best.

Thanks for the link Rob. Off for a read now…

Consistent minimums seems reasonable to me. The maximums are caused by things happening on the sun, so they are affected by how much stuff happens this time. The minimums are caused by nothing unusual happening on the sun.


Wasn’t happening for me this evening on The Cloud G/SP-015. Called and called on 20m CW. Several US and Canadian skimmers got me - but no chasers.

I then tried my luck at JT65 but again no takers despite constant activity.

The activation comprised just a single QSO on 2m FM. Hope Jimmy fancies a pint later…

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