‰  NOW 40 WPM  ‰  
CANADIAN CLASS CODES ARE SHOWN IN TABLE 3.  SECOND, ASSIGNMENT OF CLASS
CODES IS PUZZLING.  FOR EXAMPLE, BKU 344 AND CO 407 BOTH RUN 80 W, BUT THEY
USE CLASS CODE HW AND MHW, RESPECTIVELY.  BEACON LI 353 WITH 400 W IS
ASSIGNED CLASS CODE LOM, WHICH IS TYPICALLY LIMITED TO 10 W.  EVEN WHEN
TECHNICALLY CORRECT, THE DISCREPANCY BETWEEN TWO BEACONS WITH THE SAME
CLASS CODE, BUT OF VERY DIFFERENT POWERS IS PERPLEXING.  FOR INSTANCE,
CLASS CODE H IS ASSIGNED TO BOTH AES 390

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

THE NEXT 4 HOURS FOR A TOTAL OF 337 BEACONS BY 1300 UTC.  THEN, THE
PRESENCE OF BEACONS, NEW OR NOT, SIMPLY STOPPED.  UNLIKE AFTER
SUNSET, THEY DIDNT FADE OUT SLOWLY AND STEADILY, THEY SIMPLY
DISAPPEARED.  IN LESS THAN HALF AN HOUR, THE NUMBER OF BEACONS FELL
FROM 146 AT 1300 UTC TO THREE THE NEXT HOUR AND THEN ONLY FIVE MORE
BEACONS FROM THEN UNTIL SUNSET.  ALSO, THE SEPARATION BETWEEN
SUNSET/ SUNRISE PHENOMENA AT LF IS VERY SHORT.  ONLY 3 HOURS ELAPSED
BETWEEN DOUBLE DIGIT RECEPTION OF BEACONS AT SUNSET 0100 0200 UTC
AND AT SUNRISE 0901 1000 UTC.  BETWEEN THOSE TIMES, FOUR BEACONS
WERE HEARD AT 0601 0700 UTC AND THREE AT 0801 0900 UTC, WITH THE
MIDDLE HOUR 0701 0800 UTC DEVOID OF BEACONS.

GIVEN THAT, THE BRIEF PERIOD OF 3 HOURS COULD BE VIEWED AS A LULL OR
PAUSE RATHER THAN A SEPARATION, SUGGESTING THAT SOME LEVEL OF
COMMUNICATIONS COULD BE MAINTAINED CONTINUOUSLY FROM SUNSET TO
SUNRISE.  PROPAGATION ALSO VARIED ACROSS A CUMULATIVE 12 MONTH YEAR.
THE BEACON SEASON, OF COURSE, DEPENDS ON YOUR LOCATIONS LATITUDE AND
LONGITUDE, WHICH DETERMINE HOW MUCH ATMOSPHERIC NOISE IS PRESENT
DURING THE YEAR AND WHEN SOLAR CONDITIONS BEGIN TO FAVOR
‰  END OF 40 WPM TEXT  ‰