‰  NOW 35 WPM  ‰  TEXT IS FROM AUGUST 2019 QST  PAGE 40‰

ACTIVITY VERSUS TIME DATES AND TIMES OF RECEPTION WERE ANALYZED TO
DETERMINE OPTIMUM OPERATING TIMES AND IDENTIFY THE BEACON SEASON.
PROPAGATION VARIED ACROSS THE CUMULATIVE 24 HOUR UTC PERIOD OVER 3 YEARS,
AS SHOWN BY THE TOTAL NUMBER OF BEACONS LOGGED DURING 24 UTC HOURS IN
FIGURE 1.  ACTIVITY PEAKED AT 0201 0300 AND 1201 1300, WHICH COINCIDES WITH
SUNSET AND SUNRISE PERIODS.  NIGHTTIME PROPAGATION BRINGS THE BANDS ALIVE
WITH ACTIVITY.  PERIODS OF SUNSET AND SUNRISE ENHANCEMENT ACTIVITY AT NDB
FREQUENCIES NEAR 630 AND 2200 METERS ARE SHOWN IN TABLE 1.  THE GRAYLINE
NEAR LOCAL SUNSET AND SUNRISE AT NDB FREQUENCIES IS LIKE THE WELL KNOWN HF
GRAYLINE.  HOWEVER, ON NDB FREQUENCIES, THE INDIVIDUAL BEHAVIORS OF SUNSET
AND OF SUNRISE PROPAGATION ARE CLEARLY DIFFERENT FROM EACH OTHER.  FIRST,
AFTER APPROACHING AND PASSING THROUGH SUNSET, THE NUMBER OF BEACONS
INCREASED TENFOLD FROM SEVEN AT 0100 0200 UTC TO 75 BEACONS IN 4 HOURS.
THE NUMBER OF BEACONS HEARD INCREASED EACH HOUR, BUT THE INCREMENTAL AMOUNT
OF EACH INCREASE DECLINED SLOWLY AND STEADILY UNTIL NO FURTHER INCREASES
WERE NOTED AS NIGHT WENT ON.  SECOND, APPROACHING AND PASSING THROUGH
SUNRISE, THE NUMBER OF BEACONS HEARD ALSO INCREASED QUICKLY, IN FACT,
ALMOST EXPONENTIALLY, NOT IN SMALL INCREMENTS.  THE NUMBER OF BEACONS
JUMPED FROM THREE AT 0801 0900 UTC TO 18, 55, 118, AND THEN 146 BEACONS IN
‰  END OF 35 WPM TEXT  ‰  QST DE W1AW  ƒ