The "San Diego Effect" (aka: The Sack-Donnelly Effect)

THE KF6XA TO W3NRG 10 METER PROPNET EXPERIMENT
COMPARISON OF SUMMER VERSUS WINTER PROFILES
SIX METER PATH ALSO CONFIRMED

Ed Sack, W3NRG

Abstract
As an active member of the PropNET system, W3NRG has recorded thousands of ten meter
transmissions from fellow PropNET participant, KF6XA over the past four years. What makes these measurements interesting is that the path between the stations would not usually be considered "consistently viable" for 10-meter communications. A model for the transmission path has been proposed and winter and summer reception profiles compared. Recently, KF6XA and W3NRG have been able to show that the path is also viable on 6 meters, in verification of World War II research in the same area.
Introduction An "unusual" 10 meter propagation condition has been documented in the collection of over four years of data using the PropNET system.1 Thousands of automated ID’s transmitted by KF6XA and received by W3NRG provide further evidence to support an explanation for this phenomenon as it was first observed during World War II.2,4