Dear all:
As this is my first full solar-cycle as a licensed amateur, I would like to learn from the more seasoned experts about what to expect in terms of propagation on 40, 30, and 20m in the coming years.
My naïve expectation was that CONDX on 20m would improve, allowing for more DX from summits.
Now, as my activations typically take place at daytime between 9:00 a.m. and 12:00 noon UTC, I was a bit surprised that the current daytime predictions are often “poor” for 80/40/30/20m.
Is this because of the D layer attenuation relevant up to 14 MHz? And if so, is this a general pattern to expect towards the peak of the solar cycle, or circumstantial?
I got my license at the end of the last maximum in 2013 and started my portable career with the 817 - even before Sota. In this time qso could always be done on 40m and 20m all over Europe after nearly every cq call. And often American on 10m.
We are a long way from that at the moment. In the last few years I’ve had a dozen American chasers, lately I haven’t even heard anything overseas. I guess without our Sota spotting procedure I would be nearly impossible to get one single qso on a summit.
I think there are several factors operating here to reduce activity. Firstly, many of us in urban areas have to contend with high noise levels, like in my case S8 on 20m at times. This discourages HF activity. Secondly a lot of activity has shifted to digital modes at the expense of traditional modes. Thirdly, right now we are in a period called the “midsummer doldrums” which reduces the effectiveness of the HF bands, and an improvement can be expected by the end of August or early September. There is also the fact that the current sunspot cycle is more active than the last one, and while this suggests better propagation we should also expect an increase in the number of disturbed periods when propagation becomes unreliable for several days as hyperactive sunspot groups transit the face of the sun.
Hi Martin,
Most will agree HF propagation is rather all over the place at the moment with 20m opening regularly in the morning from EU/UK into VK and elsewhere. But not every morning and often with raised atmospheric noise due to CMEs and solar flares hitting the Ionosphere. I hope this will settle down a little as we move into the Northern Herisphere Autumn. As the maximum usable frequency (MUF) has to be higher than your transmit frequency along the COMPLETE route of your signal, I find the web site linked below very useful to see which path “might” be possible and on which bands: https://prop.kc2g.com/
Due to the limited time windows and that it only occurs on 40 metres and 80 metres (and to an extent 60m and 30m as well) - many people forget about grey line propagation, which is (in my experience) affected far less by the going-ons on the sun and more by timing and where the night/day line is passing though at the time that it goes over your location. Where you can contact via Greyline changes through the year due to the fact that the earths axis is not straight up and down but rather at an angle. VOACAP and other services will tell where is currently possible for dawn and dusk DX contacts.
Actually that MUF map site I referenced above also has the greyline at the current time shown on it as well.
With all the prediction tools that we have - they can only ever be a guide to a “possibility”, the only way to be sure is to get on the bands and call CQ - I have often been surprised by what I can hear and work, even when I thought it would be difficult. Other days the predictions say there should be good DX and when I try, the bands are dead! C’est La Vie!
D-layer attenuation increases at lower frequencies and will worsen as we get to the peak of the current solar cycle. It’s why 160m and 80m are - outwith contests - often very quiet / dead during the day especially in summer. It doesn’t seem to affect 30m and 20m (at least at my northerly latitude).
Having said that I’ve have successful late-morning SOTA activations on 80m using 10W of CW or SSB to an inverted V. The several failures so far this year were bad luck due to a SID following an earlier solar flare (which will be more common now that the number of sunspots is increasing).
I’ve found 40m is affected too though not as much as 80m. I always activate on 30m which - in my experience - seems to have consistently-good propagation during the day, often getting a mini pile-up from pan-EU chasers - hence it’s my favourite band.
Yes, 20m seems disappointing - but maybe, having qualified the summit on 30m, I’m impatient, getting a sore backside and legs [No I won’t carry a portable chair] and not prepared to hang around very long making multiple CQs after self-spotting.
It’s okay for chasers to jump out of bed at this early hour [or very late hour] and head for the shack (presumably to work activators mainly in other time zones).
But for activators, driving in the dark and possibly walking to the summit around dawn is asking a lot. I don’t consider that prospect much fun nor convenient to normal life, though some die-hards seem to like it.
Hi Andy,
Add several inches of snow and ice on the ground, needing to put the spikes on the hiking boots and it’s the “ideal SOTA activation” - watching the sunrise from a summit while trying to avoid frostbite in the fingers - then to bag a couple of ZL or VK contacts on 40m SSB QRP.
Not everybody’s “cup of tea” I understand but fun to a few of us (less as we get older, unfortunately).
Hello Martin,
since the sun is much more active than in recent years, the 20m-band has turned into a “night band” during summer in the northern hemisphere (or rather from spring to autumn). 20m is currently open all night and there is lots of DX especially around sunrise and sunset. During daylight, D-layer absorption is fairly high and there is not much going on from a DXers point of view.
IMO summer is not the best season for DX. The MUF is lower than in winter and the higher bands are not very reliable. Once we reach equinox, conditions will start to improve again.
You definitely need a bit of luck when planning an activation, because the K index is updated every 3 hours and can fluctuate significantly under certain circumstances.
