Thoughts on Propagation & DXing


A reply to one of my posts by Scot KA3DRR got me to thinking about how I go about DXing and what is available to the DXer to enhance their chances of snagging a new country. I’ve never really thought about the mechanics of it before – I just did it on autopilot and was happy with the results.

But there are tools available that, while useful individually, are equal to more than the sum of their parts when put all together. There are also tools which should be discarded, as they will lead you down the Path of Disappointment and along the Road of Unrealized Expectations. You don’t want to go there – it stunts the growth of would-be DXers just as surely as 2m FM.

First, the positive, useful stuff.

I’m not going to say, “Turn on the radio and do time in front of it, listening”. The internet is a great resource for DXers. Here are some relevant sites & the way to use them to your benefit:

DX Summit – most hams, including me, use this site to see what country is on the air that they may need. But it is more than that. It is a real-time propagation indicator, not a propagation predictor. It shows who is hearing what geographic area on any given band. In other words, what paths and bands are definitely open.

And it does have a very accurate role as a predictor as well. For example, it’s early morning where you are and you wonder how conditions will be after sunrise on 15 meters. Well, it is after sunrise/daylight 8-10 time zones east of you. Are those countries making spots on 15 meters? If so, the chances are better than excellent that 15m will be open for you as you approach the same local time as those making the spots.

Same for the other bands – if it’s noon local for you and stations on the other side of the world are making spots on 80 meters of all the DX they’re working during their night hours, you can be fairly sure that 80m will be good for your location during and after sunset as well.

WSPRnet – another real-time indicator of propagation. Again, these aren’t mere predictions –

Grayline path W5-Scandenavia

Morning (US) grayline path W5-Scandinavia. Opposite direction of normal 40m propagation.

this is a graphic representation of what paths are definitely open. There are certain paths that we already know about – we know that 10-15m, if open, goes east in your local morning and westerly in late afternoon/evening. Most of the time. We also know that 40-160m propagates east in the evening, west in the morning. There are exceptions though, like the morning grayline path from W5 to Scandinavia in the fall & winter months.

North-south and polar paths on any band are less predictable but their presence or absence on WSPRnet will give you an idea of band conditions and who you may expect to work. Put another way, WSPRnet is also a good indicator of which paths are not open, which is just as important to know. It also illustrates the oddities that sometimes exist in the pseudoscience of ionospheric magic – check out this occurrence I experienced on 30 meters.

The map on WSPRnet can be filtered by band and over a given length of time. Sometimes while I’m at work in the morning, I check the WSPRnet map for 80 meters over the previous 12 hours to see whether or not I missed a good DX evening by choosing to sleep rather than DX!

In summary, WSPR is a mode that may well benefit the non- WSPR station as much (or more!) than the stations actually on the air in that mode, simply by having its results available online for all to see.

Besides the online sources, there are a couple shareware programs that are useful.

DX Monitor is similar to the DX Cluster website but with added features that are helpful. For example, you can have spotters within a given range of your QTH show up as highlighted from other spotters. I live near Houston and have stations within 500 miles set to show up highlighted with the reason being that if they can hear a given DX station, I probably can too. If a JA spots a VS6, that doesn’t really do me any good but if a station in Dallas spots the VS6, that’s a different story.

Another program and learning tool is DX Atlas. It’s interesting, after working a country on an unusual path, time or band, to see the relationship between your QTH, his QTH and the zone of day/night. Several websites can display this information as well but DX Monitor lets you display the map in a variety of coordinates. It also allows you to mark your QTH and put colored pins to mark the countries you’ve worked.

Another useful tool is your own logbook. How much DX did you work during this week a year ago? Two, three years ago? Not a propagation predictor so much as a trend indicator in the solar cycle, but interesting nonetheless.

And now, what to avoid?


Conditions on 10m (22Jan 2010 @ 1500Z) vs *prediction*

Those propagation predictor icons! My logbook is a testimony to their uselessness, as is the DX Cluster and the WSPRnet map. I hate to think that a new potential DXer is giving them credibility and making decisions on whether or not to operate based on a Poor indication on HF. True, 10m is rarely open as those icons will accurately indicate. But with the same Poor indication on 17m, I’m working a UA0. Or a ZL on 12m. Next time you see a HF-Poor indication, check the WSPRnet map or the DX Cluster and see all the DXing going on!

Another thing to avoid as if they carried Yersinia pestis are the naysayers. Ham radio is full of them. They are full of insightful tidbits like “You can’t work DX on 80m with a dipole that low!” or “You need a kilowatt and a Yagi to get 5B-DXCC!” I spent the first 15 years in the hobby believing such bovine scatologists before seeing it for what it was.

Ringing in the New Year under poor condx at AE5X:

100 watts, an 80m dipole and "Poor" conditions!

100 watts, an 80m dipole and "Poor"!