Issue 46 Six News, August 1995
by Emil Pocock, W3EP
The US stations on 288-degree Line to
IO91
The six-meter openings to North America during June and early July were unprecedented in number, duration, and geographical extent. The band was open on 15 days from North America to somewhere in Europe during June alone for more than 60 hours! Nevertheless, signals were generally marginal to mediocre, with most of the activity on CW. Europeans were typically 529 - and often that was a generous report. During most of the openings, only the better equipped stations got consistent results. Thus the 'l0-watters' on both sides had a frustrating time trying to make it across. This has not always been the case. In previous years, transatlantic sporadic-E signals were sometimes very loud and much of the activity was on SSB. Even the smaller stations were able to participate. Why the big difference this year is unknown.
We typically listened for the Spanish and Portuguese television video around 48.250 MHz to give us hint of an opening. When the video built up to moderate levels, several of the more active and better equipped stations begin calling CQ on CW somewhere between 50.100 and
50.125 MHz, but rarely right on 50.110! We tried to leave that frequency open to listen for DX calling our way - although not everyone co-operated. As the band opened, we began to get answers from our CQs by one or more weak stations, often competing with each other and the noise for attention. Picking out stations was sometimes a great struggle! Some of the openings sometimes went on for hours without signals increasing substantially.
So what sort of stations were you hearing? Contrary to rumors, we do not run excessive power. Even though the maximum legal output is 1500 Watts PEP, few Americans even run that much. The table (see page 56) shows some of the stations that have appeared most frequently on the UK packet cluster. (Thanks to G3SWX for sending me a selection of packet listings.) The list is arbitrary and selective, but it represents a typical cross-section of the active 6-meter stations over here. These stations do have some common characteristics that make them successful. Much effort goes into putting up a good antenna. The typical DXer's antenna is at least 6 elements on a 6-meter (20-foot) boom, but usually somewhat larger than that. It is on top of a tower at least 18 meters (60 Feet) high, located in the clear on top of a prominent hill.
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If the typical American station has a weakness, it is in the receiver. Many of us have moderate to severe local noise problems, generated by faulty power lines, computers, television sets, leaky cable TV lines, and who knows what else. Commercial receivers just cannot deal with noise, weak signals, and strong adjacent stations simultaneously. We often have the impression that you are hearing us better than we are hearing you (with some notable exceptions). Power and antenna differentials can account for this, and even though many of us have great sites, noise is often the limiting factor.
So why, do you ask, did we hear the same VEl, VE9 and W1 stations day after day? Part of the answer is that you were hearing the better stations in an area of North America that seems favoured for transatlantic sporadic E. You were also hearing stations whose operators happened to be home during the weekdays. Some are retired, others teach in the schools and universities and have the summers off, some are employed at home, and more than one six-meter fanatic plans his holidays for the sporadic-E season! Some even monitor the band 24 hours a day, as long as they are home.
The map shows the location of the stations listed in the table. Superimposed is a line representing a 288-degree bearing from London with an approximate distance scale in kilometers. Sporadic E to the American North-east is undoubtedly via three hops up to a maximum distance of about 6600 to 6900 km. Longer distances probably require at least four hops. When Florida stations are working the UK, those in the Northeast can usually
hear them quite well, suggesting that an extra forth hop is involved. Sometimes the Northeast has heard Florida running Europeans and could not hear a single DX station! We supposed the propagation was just a bit too seaward and would wait for the sporadic-E clouds to drift our way.
73 Emil
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