We get new visitors here all the time. I haven’t mentioned the Hepburn Tropo Forecast maps in some time, so here’s a link. It’s worth getting acquainted with this site: http://www.dxinfocentre.com/tropo.html
The thing to realize with the Hepburn maps is that they are forecasts. So like the weather, it doesn’t always pan out. It’s a good idea to call CQ any old time, and not fall into the trap of “just listening”. If everybody listens, and nobody calls, then the band is always closed, right?
But in the wintertime, we can go weeks at a time with those flat, black map conditions. So even a bit of blue or green/blue can mean some enhancement. Come warmer weather, we can get into green or yellow openings, and when those actually end up being true, that’s when guys can get out 300, 500, 700 miles. Best thing to do is follow those maps (they update each day about 1pm) and just learn the general tendencies.
144.200 is the call freq. on 2m SSB, and activity can occur from about 144.150 up to 144.250. Typically the action is closer to the call freq. and as things get busier, guys spread out. Don’t make the mistake of having long ragchews on 144.200, esp. if the band is up. Guys have different opinions about the call freq. but mine is to use it lightly. You certainly want to start things there, that’s the whole point. But don’t get in the habit of having long ragchews on 144.200, especially with locals, and especially without giving frequent pauses for others to jump in. Guys in cities are prone to having ragchews on the call freq. like it’s a dang repeater. Don’t do that. The problem with that is if anyone who is DX is trying to call from far away, they’ll never be heard over your local ragchew. If I get in longer Q’s with someone, I like to slide them up or down at least 5 or 10kc, to leave the call freq. open for others. You get the hang of it after a while.
There’s another map that you want to monitor — a real-time propagation logger based on 2m APRS spots.
http://www.mountainlake.k12.mn.us/ham/aprs/path.cgi?map=na This map can be glitchy at times, but it’s a great tool. It updates often, so hit refresh. It can be interesting to see colors darken as we head into evening, when conditions often improve — especially in summer and fall.
Again, don’t let these maps tell you when to play radio. One benefit of doing these nets weekly is that you learn a lot about propagation over time. There are nights where the maps don’t show any potential, and you still hear that guy in Detroit (who’s usually S1 or S2) come booming in S7, S9. There are also times where the maps seem like you should have great conditions, and they’re nothing special.
But you’ll rarely miss a big opening if you check these maps like you would the weather forecast on the news.
Without getting too technical, I need to add that these links are basically showing when we expect, or are having temperature inversions. An inversion is when the temperature is warmer aloft than it is at the surface. That is a good setup for enhanced band conditions on VHF/UHF. There’s more to it, but that’s a good start.
The skip that is so common on 6m, called sporadic E skip, is a whole different deal — not dependent on weather. Es is typically seasonal, with the clear peak in May thru July. It can also pop up again a bit during Dec./Jan. Actually, E skip can pop up at any time of the year, but summer’s the high season, no doubt. A lot of guys keep a rig tuned to 50.125 in the background, because 6m SSB (and FM, up near 52.525) can open up just like that. That’s why they call 6 meters The Magic Band.
Somebody remind me to make a separate post about 6m sometime. There’s a few simple things to learn, that make you a smarter op, and make life smoother for everyone who enjoys 6. Or if someone has a nice link that explains the band plan on 6, and some basic gentleman’s agreements, share it here. With summer not so far away, it’s a good time to learn how to work 6m like a veteran.
