Hidden Openings

Those active in last weekend's ARRL DX SSB contest are likely aware of a peculiar opening on 10 meters on Sunday. The band to Europe and even further points from North America was better than on Saturday and arguably better than expected for a solar flux below 100 at this time of year. But that's when it got very strange. Here is an illustrative excerpt from my Cabrillo log:

QSO: 28484 PH 2016-03-06 1827 VE3VN         59  ON     S58N          59  K
QSO: 28507 PH 2016-03-06 1830 VE3VN         59  ON     F8ARK         59  1K
QSO: 28395 PH 2016-03-06 1837 VE3VN         59  ON     EA2LMI        59  100
QSO: 28402 PH 2016-03-06 1838 VE3VN         59  ON     HA1AG         59  KW

Notice the QSOs with stations in central and eastern Europe that took place up to 2 hours after their local sunset. These occurred immediately after I took a lunch break when I was sure 10 meters was finally closed to Europe. My operation was very casual -- 95% S & P and 17.5 hours -- which gave me freedom to tune around to see what I could find.

What happened? It was a common theme in the reports filed on 3830. The answer appears to lie with the sun. A bright visual aurora was reported at that time (early evening) in Scandinavia. That was a hint.

Later in the day I browsed to WM7D's web site to check on the geomagnetic indices. At right is a screen shot taken the next day that shows the entire story. The Kp index spiked to 5 in the period 1500-1800Z and kept climbing. My guess is that the auroral activity created a high MUF auroral-E region in northern Europe, linking European signals to the F-layer propagation over the north Atlantic.

Contests as a propagation tell

Let's face it, if there hadn't been a major contest underway this delightful opening is very likely to have gone unnoticed. Would you be looking toward eastern Europe on 10 meters at that time of day? I know that I would not. Contests drive an intensity of activity rarely seen at other times. The relentless pursuit by thousands of hams for QSOs and multipliers leaves no opening undiscovered.

Why openings are hidden

Hidden openings like these are only hidden because we don't look for them. This happens on HF more than many realize. It would not be typical on bands such as 6 meters where unusual propagation is the norm. There are many beacons and dedicated enthusiasts who find and advertise openings when they happen or appear imminent.


Imagine the following scenario. You might find it familiar. It's late afternoon and you are tuning 15 meters with the beam pointing northwest. The K index is low so you are expecting an opening to Japan and possibly southeast Asia. You hear nothing from that direction. So you call CQ. Again, nothing.

You then run across a Caribbean station, easily copied off the back of your beam. He finishes the QSO and you hear a pile-up respond. They are mostly Japanese stations. Clearly the band is wide open. What is going on?

The obvious answer is that they want to talk to the Caribbean station, not you. But of all the stations in that part of the world you would think a few are willing to work any DX. This is not an isolated example. The same result often occurs when the JA is calling CQ toward North America, and indeed for most hams thoughout the world who call CQ DX.

Tuning across the bands most days is not as inspiring as it was years ago. Casual QSOs, DX or otherwise, seem to be on the wane. My guess is that the casual QSO appeals less as we grow older since we've done it so many times. This shows up in the aggregate since the ham population is getting older here and elsewhere.

It was a surprise to me when I returned to the hobby after being away for 20 years. The prevalence of the "599" QSO, without so much as an exchange of names, seemed to have become the norm. What we now find is the intense pursuit of awards such as DXCC and its endless sub-categories, and contesting. Every day the bands seem emptier yet the participation in CQ WW and many other contests grows. DX competitions such as DX Marathon appeal to the retirement crowd (soon a majority of hams) who have the time to invest in these activities.

I am as guilty as anyone. Sure, I try new things, but DXing and contesting are the majority of my activity. To counter this I regularly make a point of calling most anyone just for the sake of doing it. But that doesn't compensate. Calling CQ on a seemingly dead band is something else I will occasionally do.

A story from my youth

I had the misfortune to become a ham in 1972 during the waning years of solar cycle 20. Like cycle 24 (the current cycle) the peak was mediocre. The decline therefore offered poorer than normal conditions, and the storm activity was high. During the depths of a minimum during the mid-1970s the solar flux would stay below 70 for days at a time. It doesn't get any lower than 66, the value of a quiet sun. Openings on 10 meters were rare and 15 meters was hit or miss.

Being a VE4 tucked just beneath the auroral oval the waning years of a solar cycle were a poor time to pursue DX. I still did of course; I really didn't know better, except for the fantastic stories the old times told of cycle 19. The contesting activity by me and my friends centred on ARRL Sweepstakes. The few DX contests I entered were done multi-op if only to relieve the monotony of depressingly low rates with conversation, especially on the low bands during the long winter nights. Working DX, sometimes any DX, could be quite exciting.

One day while relaxing at the university club station VE4UM a friend (still a friend and a contester) and I had a good-natured argument over who was the better DXer. The argument went something along the lines that I had the smaller home station and so had to hone my skills more than he did with his better station. We decided to put it to the test.

We walked over to the club's operating desk. Each of us would in turn call CQ DX on 20 SSB (this was the middle of the day) and see who caught the better DX. Well, this is hardly much of a contest but it was simple to do and it appealed to our humour.

I went first. I turned the yagi north (to enthusiastic laughter from my friend and a few onlookers). The first CQ came up empty. The second drew a weak signal that required asking for a repeat. It was a VU station. We were all stunned. Who would have thought that there'd be a workable opening over the pole midday in mid-winter in the depths of a solar minimum? Yet there it was.

When my friend sat down for his turn the pressure was on. I would be hard to beat. To more laughter his CQ drew a response from a friend of ours from across town who called in to say hello. The accidental discovery of a hidden opening won the day.

The lesson

How many more hidden openings are there? I'm sure there are many. Unless it's a band with numerous watchers and beacons, such as on VHF, most likely go unnoticed. The reason is that we don't try. That's a shame. The magic of radio is in part about not knowing what might happen when you venture to transmit a CQ into the aether. Clicking on spots from the global spotting networks is convenient and a great time saver, but we should also occasionally venture beyond that.

Every now and then I put out a CQ into an apparently dead band. You just never know what hidden opening might be there for the taking. The anticipation of who might answer harkens back to decades ago when every QSO brought excitement. These foolish attempts to find an opening no one else suspects helps to keep me young. That the majority of these lonely CQs fails doesn't damp my enthusiasm.