‰  NOW 30 WPM  ‰  TEXT IS FROM MAY 2015  QST  PAGE 41 ‰

CAUSING A 5 MS GAP IN RECEIVER NOISE FOLLOWED BY A NEGATIVE AMPLITUDE
EXCURSION OF THE BASELINE LASTING FROM 65R2 MS TO 126R1 MS.  THAT EVENT
MARKS THE TRANSMISSION OF THE 60R9 MS DIT DURATION.  THE TRANSCEIVER
RECOVERS FROM TRANSMIT TO RECEIVE MODE BETWEEN 126R1 AND 182R5 MS, AND THE
RECEIVER IS BACK ON AT 182R5 MS.  A RETURN PULSE SHORT DELAYED ECHO STARTS
AT APPROXIMATELY 217R4 MS AND ENDS AT 277R8 MS, FOLLOWED BY MORE RECEIVER
NOISE.  THE TRANSMITTED PULSE WIDTH WAS APPROXIMATELY 60R9 MS.  I ESTIMATED
THE ECHO PULSE DURATION AS 60R4 MS, WHICH IS VERY CLOSE TO THE TRANSMITTED
PULSE WIDTH.  PICKING START AND END TIMES OF THE ECHO IN THE PRESENCE OF
NOISE IS NOT EXACT.  THE DELAY BETWEEN TRANSMISSION AND ECHO RECEPTION WAS
APPROXIMATELY 152R2 MS.  BY COMPARISON, PROPAGATION DELAY TIME FOR A TRIP
AROUND EARTH OR HALFWAY AND BACK IS SLIGHTLY LONGER THAN 138 MS.  MY
EARLIER REPORT ON 80 METER BAND SHORT DELAYED ECHO OBSERVATIONS APPEARED IN
THE JUNE 2007 ISSUE OF QST.  SEVERAL AMATEURS RESPONDED IN QSTS MARCH 2009
TECHNICAL CORRESPONDENCE COLUMN, AND PROVIDED SEVERAL POSSIBLE EXPLANATIONS
FOR ECHOES WITH TIME DELAYS LONGER THAN A SIGNAL GOING AROUND EARTH.  A
‰  END OF 30 WPM TEXT  ‰  QST DE W1AW  ƒ