Every year throughout the month of June, I’m impressed by the fact that it doesn’t get dark until approximately 8:30 p.m.
It reminds me of the day when some radio stations, whose frequencies were on the AM broadcast band, signed off at sundown. In the 1940s through the 1970s, the Federal Communications Commission granted licenses to thousands of radio stations to broadcast during daylight hours only so that they would not interfere with others who shared those frequencies. At nighttime the ionosphere cools making it conducive for AM stations’ signals to travel hundreds of miles. During the daytime an AM radio station with maximum power typically wouldn’t reach more than 150 miles.
I remember that during June and July, WKOR-AM (Starkville) and WVOK (Birmingham) signed off the air at 8. WCPC-AM (Houston, Miss.) stretched out its broadcasting schedule to 8:15. My friend Chuck Buell, who was the nighttime personality on WLS-AM in Chicago, was commissioned by several daytime-only stations to record their signoff announcements.
Listeners were informed that the station was leaving the air for the night and encouraged to turn their dials to 890 to listen to WLS, the only station in the country broadcasting at 890 kilohertz.
[1.] ionosphere (i-OHN-us-fear)
A. the western horizon
B. the eastern horizon
C. the region of the atmosphere consisting of several ionized layers
D. “out there in radio land”
[2.] kilohertz (KILL-uh-hurts)
B. a measure of frequency equal to one thousand cycles per second
C. a measure of frequency equal to one cycle per second
D. electromagnetic static typically heard on AM radio during thunderstorms
[3.] The first day of summer
A. is the worst time for AM broadcasting.
B. has the most daylight than any other day.
C. is in June.
D. is in July.
[4.] Which one is correct?
A. It’s Central Standard Time during the summer in Mississippi.
B. It’s Central Daylight Time during the summer in Mississippi.
C. It’s Central Daylight Time during the winter in Mississippi.
D. There are more AM daytime-only stations than FM stations.
No. 1 is C. Dictionary.com points out that the ionosphere extends from about 50 to 250 miles above the earth’s surface.
No. 2 is B. WLS-AM operates on 890 kilohertz; its waves are propagated at a rate of 890,000 cycles per second.
No. 3 is C.
No. 4 is B.
Editor’s Note: Don R. Vaughan, Ph.D., is the pastor of Mt. Vernon Baptist Church near Eupora and is on the faculty of East Mississippi Community College, Golden Triangle Campus. Contact him at firstname.lastname@example.org.