Wednesday, April 22, 2015

Good Conditions

The past week has been cycling between very good and very poor propagation conditions on the HF bands. The high solar flux (~150) is a plus as is the season (just past the equinox). Except when we also get a mix of X-ray flares and geomagnetic disturbances. Here in the mid-northern latitudes we often lose good DX propagation since even minor geomagnetic disturbances cause high attenuation on paths in the quadrant between the northeast and northwest, which covers pretty much all of Asia.

Although propagation and solar prediction are inexact sciences we at least have a surfeit of data in comparison to past decades. That is, we may not know tomorrow's (or this evening's) conditions but we can explain current conditions in exquisite detail. This is the equivalent of discounting weather forecasts to having a look out the window.

Like looking out the window to determine the weather the best way to determine conditions is to turn on the radio and listen. I try to do this often even when I have no intention of making any contacts. It only takes a few minutes. Not only do I get a better feeling of what's going on I sometimes discover unexpectedly good conditions. This occurred on Monday evening this week. The temptation to get active was irresistible.

With the yagi pointing northeast I was looking for early morning activity from stations in Russia, the middle east and east Asia, with one ear out for a rarer south Asian midday opening. Good conditions may not be enough since few stations are likely to be active on a weekday morning where most hams are instead heading off to work.

Perfect for QRP

Although I now typically transmit with 100 watts I can recognize conditions that are ideal for QRP. After all, with only 5 watts the difference has to be made up with exceptional propagation, up to 10 or 20 db enhancement, or more. That evening on 20 meters I was surprised by strong signals from the other side of the world.

There were S9+ signals from a host of juicy DX tidbits: 4X, 9K, EK, A6, HZ, SV5, 3B9, among many others. These are always good catches though none are especially rare. The thing is this was the kind of night when, with QRP, I would have been in heaven. With 100 watts I easily worked every station I called.

While this one path on 20 meters was excellent the same was not true elsewhere. Signals on 30 and 40 were unexceptional and almost no DX was heard on 17 meters other than TX5P on Clipperton Island. Higher bands were closed. The polar path on 20 was heavily attenuated allowing only the strongest signals through. These included JT and a variety of Siberians. All this data told me that the auroral zone was active and that the MUF to the northeast was most likely only slightly above 14 MHz. European signals were also quite good, though there were few to be heard since for them it was the middle of the night.

You can never have it all. Appreciate what you get and work it when the propagation gods smile upon you. Great conditions rarely last. This is particularly worth noting if you run QRP or have poor antennas.

Making propagation

The next evening (Tuesday) the conditions were worse. A series of X-ray flares had ruined most paths on the higher bands. I went lower and found mediocre propagation on 30 on 40 and little in the way of exciting DX. On a whim I went down to 80 and tuned the CW segment. With my noise and poor antenna I didn't expect much, and that's just what I got: nothing.

On my final spin of the dial a strong and steady S9 signal calling CQ caught my attention. I expected it to from the US. Instead it was HA8RM, a call often heard during contests. I listened to his unanswered CQs for a few minutes while I scanned my email on the shack computer. It was more interesting to me to see who would go back to him than to call him myself; I've worked him many times, including with QRP on 80.

In the end I decided to answer his CQ just so he wouldn't think propagation was dead. I mentioned to him (Peter) that conditions seemed to be good. He told me he was running a kilowatt and a 2-element yagi. Yes, those are good conditions! When the ionosphere is less than cooperative an exceptional station often can make up the difference. If I was running QRP I am sure I would have worked him just as easily. His station is that good.

Which goes to show that with a sufficiency of time and money you can go a long way towards making your own good conditions. The rest of us have to make do with what bones nature tosses our way.

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