Exploring the Mysteries of Long and Skewed Path DXing Panel Discussion By W6YA – K6NA – W6YI

Propagation programs for predicting long path openings are generally worthless

Long Path = opposite the shortest path Gray Line = propagation along the terminator Long path has traditionally referred to opposite ends of the terminator This is disputed by K9LA and others with regard to 80 and 160 meters. See his excellent 2014 webinar

K9LA webinar A Long Overdue Review of Gray Line Propagation on the Low Bands wwrof.org/webinar-archive (older posts) search for K9LA

In General Point your antenna southwest in AM Most common long path is on 20m after sunrise to Europe, Middle East Most long path is probably skewed For Africa & South Atlantic, point the antenna opposite the usual short path bearing LP to South Africa is active all year

CQ Magazine ran the first article about gray line DXing on 80 meters Published in September, 1975, it was the result of DX contacts by K6UA and W6NLZ

K9LA believes the green line is the true path on 80m

Let’s explore our experiences band by band Beginning with 20 meters Usual morning path after sunrise Often a very skewed path (VU, A5) VK6 afternoon path at his sunrise Evening south path around sunset Equinox variations 4S7RO

40 Meters Winter morning LP to Europe, Middle East, Indian Ocean, SEA, etc. LP often occurs before sunrise but peaks well afterward as on 20m. Fall equinox brings surprise paths Some Africa/Indian Ocean in summer Evening LP near sunset to Eastern Asia (VU, etc.) in fall and early winter HA8RM

75/80 Meters Apparently a skewed path Few have directional gain antennas Morning LP much like 40m but rarer Shorter time peaking before sunrise Skewed sunset path over the top of South America 9K2HN

160 Meters Very few Have directional antennas Several CA stations worked A61AJ years ago one morning on what was assumed to be long path No other known LP from CA N7UA worked A61AJ and 5B4AGN LP from his QTH near Seattle

30 Meters Propagation similar to 40m long path Directional antennas becoming more common with SteppIR popularity SP and LP often open simultaneously This creates a problem with multipath echo using omnidirectional antennas Evening LP similar to 40m in winter 9N7BCC

15 Meters Morning long path is similar to 20m Less common than on 20m Occurs most often during cycle peaks Rarer LP can occur in mid-late evening after mid winter Rarest LP can occur from Middle East to Eastern Asia in mornings after mid winter, well after sunrise time A45XR

17 Meters Similar to 20m and 15m morning long path but less common More experience is needed by most of us

12 and 10 Meters More experience is needed for 12m Evening LP is similar to 15 meters Morning LP is similar to 15 meters Incidence is greatest during highest cycle peaks Morning LP may be open at the same time as SP to Europe A45XR 10m

Please tell us about your unusual experiences with long path on all bands, other than what was described in this discussion. We all have much to learn about these unusual paths. Predictions with software, such as VOACAP, ICECAP, HAMCAP, W6EL PROP all are unreliable for predicting long path conditions, suggesting these paths may be more complex than was previously believed. This is one of the reasons that DXing is more fun than internet communication!