THE MARCH OF CHANGE (Audio)

THE MARCH OF CHANGE

March 29, 1941, has become a mere footnote to broadcasting history.

But it was a Saturday of mass confusion when 802 of the country’s 890 radio stations changed frequencies at 3:00 a.m. in accordance with the North American Regional Broadcasting Agreement signed by the United States, Canada, Mexico and Cuba.

It all began on November 1, 1937, when representatives of the four countries met in Havana to coordinate each country‘s AM radio wavelength assignments to prevent interference with the others’ stations.

After six weeks of negotiation, the agreement - also known as The Havana Act - was signed on December 13, 1937, subject to approval by all four countries’ legislatures. The Cuban government was the first to approve the pact nine days later, Canada and the United States followed suite in 1938 and Mexico finally agreed in late 1939. Stations in Haiti and the Dominican Republic were also included in the pact.

The NARBA expanded the AM dial, (from 550 to 1500 kilocycles), to 540 to 1600 kilocycles and divided the dial by ten kilocycle increments into 106 channels. The channels were then divided into three classes: Clear, Regional and Local.

Clear Channels were defined as those in which the dominant station(s) rendered service over wide areas and clear of objectionable interference. Fifty-nine frequencies were assigned as Clear Channels.

Regional Channels were defined as those in which several stations could operate with power limited to 5,000 watts. The power of stations operating on the 41 Regional Channels was limited to prevent interference with others.

Finally, the six Local Channels were defined as those in which stations limited to 250 watts could operate without interfering with others.

Adjustments were made in these provisions as time went on, particularly after World War II. But when the NARBA went into effect in 1941, 802 of the stations in the United States - almost 90% of them - were mandated to change frequencies to comply. (1)

Some of the country’s most famous call-signs were affected. Of the 37 major stations operating in 1941 with 50,000 watts, only eight avoided the change:

                    KDKA/Pittsburgh, 980 to 1020
                    KFI/Los Angeles, 640 Unchanged
                    KMOX/St Louis, 1090 to 1120
                    KNX/Los Angeles, 1050 to 1070
                    KOA/Denver, 830 to 850
                    KPO/San Francisco, 680 Unchanged
                    KRLD/Dallas-Ft Worth, 1040 to 1080
                    KSL/Salt Lake City, 1130 to 1160
                    KSTP/Minneapolis- St. Paul, 1460 to 1500
                    KYW/Philadelphia, 1020 to 1060
                    WABC/New York, 860 to 880
                    WBAP & WFAA/Dallas-Ft Worth, 800 to 820**
                    WBBM/Chicago, 770 to 780
                    WBT/Charlotte, 1080 to 1110
                    WBZ/Boston, 990 to 1030
                    WCAU/Philadelphia, 1170 to 1200
                    WCCO/Minneapolis-St Paul, 810 to 830
                    WCKY/Cincinnati, 1490 to 1580
                    WEAF/New York, 660 Unchanged
                    WENR & WLS/Chicago, 870 to 890**
                    WGN/Chicago, 620 Unchanged
                    WGY/Schenectady, 790 to 810
                    WHAM/Rochester, 1150 to 1180
                    WHAS/Louisville, 820 to 840
                    WHO/Des Moines, 1000 to 1040
                    WJR/Detroit, 750 to 760
                    WJSV/Washington, 1460 to 1500
                    WJZ/New York, 760 to 770
                    WLW/Cincinnati, 700 Unchanged
                    WMAQ/Chicago, 670 Unchanged
                    WOAI/San Antonio, 1190 to 1210
                    WOR/Newark, 710 Unchanged
                    WSB/Atlanta, 740 to 750
                    WSM/Nashville, 650 Unchanged
                    WTAM/Cleveland, 1070 to 1100
                    WTIC/Hartford, 1040 to 1080
                    WWL/New Orleans, 850 to 870
                    ** Stations sharing frequencies.

Listeners couldn’t say they weren’t forewarned. Radio stations peppered the air with announcements of the switch for months. They included a series of recorded announcements provided by RCA that urged set owners to visit radio repair shops to have the push buttons on their radios reset - not a job for amateurs in the those days.

As you can hear in the RCA radio spots A, B, C and D also posted below, listeners were also encouraged to replace weak radio tubes with “genuine RCA tubes.” The spots were conveniently open-ended for local dealer tags. Apparently the campaign worked because radio set tube sales in 1941 leaped nearly 25% to $143,000,000 from 1940’s $115,000,000.

Stations, meanwhile, had their own technical expenses. The National Association of Broadcasters estimated the aggregate cost to stations for the frequency switches was $1,500,000.

Broadcast engineering consultant Mark Durenberger informs that, “Frequency changes could wreck havoc. Stations might have to physically shorten or lengthen towers. Depending on frequency assignment they might need additional ground wires. Transmitters sometimes could be modified - tuning units needed extensive work in most cases. New crystals had to be ordered causing a big backlog for stations that waited until the last minute.”

Whether associated with the many frequency switches or not, ratings suffered. The average rating of the nation’s Top 50 programs in April, 1941, immediately following the alignment, fell over nine percent compared to April, 1940.

But, as pointed out in Network Radio Ratings, 1932-1953, radio was enjoying the best of times - annual industry revenues had totaled more than $200 Million in 1940, with no signs of slowing down.

To station owners the frequency alignment was simply a bothersome cost of doing business. Audience and income levels would continue to rise through most of the decade.

(1) The 91 stations between 550 to 720 kilocycles escaped wavelength change.
     The 21 stations between 740 and 780 kilocycles moved up the dial ten kilocycles.
     The 22 stations between 790 and 870 moved up 20 kc.
     The 633 stations between 880 and 1450 moved up 30 kc; eleven advanced 40 kc.
     The Eleven stations between 1460 and 1490 moved up 40 kc.
     The 63 stations at 1500 moved down ten kc.
     41 stations were assigned to new frequencies different than the above formulas.

                Copyright © 2015 Jim Ramsburg, Estero FL   Email: tojimramsburg@gmail.com