Radio Programming and Advertising

Caracas skyline (photo credit: Pablo Verdin)

Radio signals are electromagnetic waves that are sent from a transmitter to one or more receivers.  All electromagnetic waves travel at the speed of light, but they can different wavelengths and frequencies.  Radio signals occupy certain ranges of the electromagnetic spectrum.

First of all, there is the AM band of frequencies.  There are electromagnetic waves with frequencies between 535kHz and 1605kHz (where a "kHz" is a kilo Hertz, or 1000 oscillations or cycles per second).  The AM (Amplitude Modulation) method involves the encoding of the original sound through modulating or changing the amplitude of the radio signal, which is then decoded by the receiver to recover the original sound.

Each AM channel is assigned a range of frequencies, typically about 10kHz wide.  The common frequency identification (such as AM 1590 for Radio Deporte in Caracas) represents the midpoint of this operating channel range.  Actually uses only about 2.5kHz on either side of this midpoint because of interference problems outside.  Therefore, the total bandwidth of an AM channel is typically about 5kHz.  The musical range of the human ear is about 20kHz, and that is the reason why AM sound imperfect.

Theoretically, there can be at most (1605-535) / 10 = 107 AM stations in an area.  In practice, the number of AM stations in area is much lower for a number of other reasons.  Am signals can be reflected from the ionosphere layer back to earth, so that the signals can reach unintended places that are thousands of miles away.  Furthermore, the ionospheric reflection is increased during night time.  Therefore, the AM signal from a powerful station in one city can be received in another city, which may be in another country.  for example, when Cuba was attempting to interfere with the broadcasts of Radio Martí in Florida, their signals were interfere with a radio station in Iowa, which is deep in the heartland of USA.  Consequently, AM signals are often subject to regulations such as the use of directional antennae or reduced power at night time or even going off the air at night.

Then there is the FM band of frequencies.  These correspond to electromagnetic waves with frequencies between 88mHz and 108mHz (where a "mHz" represents a million Hertz, or 1,000,000 oscillations or cycles per second).  The FM (Frequency Modulation) method involves the encoding of the original sound through modulating or changing the frequency of the radio signal, which is then decoded by the receiver to recover the original sound.

Each FM channel is assigned a bandwidth of 200mHz, and the midpoint of this operating channel range is used for identification purposes (such as FM 92.3 for Capital FM in Caracas).  This means that there can be at most a maximum of (108-88)/0.2 = 100 stations on the FM dial.  The FM bandwidth can easily cover the musical range of the human ear of about 20kHz, and that is why FM radio sounds so much better than AM radio.  The bandwidth allows FM to be broadcast in stereo.

At the higher frequencies, the FM signals pass unreflected through the ionosphere, during the day as well the night.  In other words, the FM signals operate by line of sight.  Of course, this limits the coverage area of a FM channel.  The size of the coverage area depends on the height of the transmission antenna, which is often located at the top of very tall buildings.

The above discourse on the physics of radio engineering serves to bring out the important point that the number of radio stations that can operate in an area is limited.  For this reason, the radio spectrum is regarded as public property which is licensed to designated operators under some conditions, such as the payment of licensing fees and restriction on programming content.  Given the fact that radio station operators must pay licensing fees as well as incur expenses for capital equipment, staff and operations, they are mostly funded by revenues from advertisers and sponsors.  

Given this operating environment, as much as some people would like to advocate unconditional free speech, this is not possible in practice.  At the bottom of this page, we have included the regulations (in the original Spanish) that pertain to FM radio broadcasting in Venezuela.  These regulations specify certain restrictions on programming and advertising, including the following:

These would appear to be requirements that meet commonsense.  But the interpretation of some of these rules (such as the prohibition of commercial messages that "have not been approved by the appropriate authority when such is required") may be problematic and can result in authoritarian excesses.

On the consumer side, as in the case of virtually all media, they have to accept a bargain in which they are obliged to accept the advertisements in return for the information and entertainment.  Some of these consumers may have decided to automatically tune out whenever commercials appear.  But some good commercials may be just as entertaining and/informative as the regular program content, and can attract the attention of even the most jaded audience. 

We will now cite some data from TGI Venezuela.  This is a survey of 3,218 persons between the ages of 12 and 64 years old conducted by CVI (Compañía Venezolana de Investigación de Mercado) in Caracas during 1999.  During the interview, the respondents were asked to rate their level of attention to radio advertisements on a five point scale, with 5 representing "Always" and 1 as "Never."  32% of the respondents choose the 5 option for "Always" and another 15% choose the 4 option, so that the top two options was chosen by 32% + 15% = 47% of the people.  The following table shows the results by age/sex, with a frequency distribution that exhibits some unusual age/sex interactions.  On the male side, this is a unimodal distribution peaking in the middle.  On the female side, this is a bimodal distribution, with peaks for young and old women.

Age/Sex Group % choosing 5 for "Always" % choosing 5 or 4
Male 12-19 years old
Male 20-24 years old
Male 25-34 years old
Male 35-44 years old
Male 45-54 years old
Male 55-64 years old

Female 12-19 years old
Female 20-24 years old
Female 25-34 years old
Female 35-44 years old
Female 45-54 years old
Female 55-64 years old


TOTAL 32% 47%

(source:  TGI Venezuela)

Traffic jam in Caracas (photo credit: Pablo Verdin)

It is common knowledge that much of radio listening takes place while the listeners are in cars, either as drivers or passengers.  In this environment, radio does not have any competition from television or print media.  For drivers, reading magazines or watching television would be dangerously distracting.  In more recent times, the use of cellular telephones while driving is becoming a controversial issue, since it has allegedly caused unsafe driving because of the mental and physical distractions.  Given the fact that radio listening in cars is an accepted behavior, one may come to the logical deduction that these radio listeners are in fact not paying full attention to the radio medium while driving.  This would detract from its value as an advertising vehicle.

During the TGI Venezuela survey, the respondents were shown this statement, "I always listen to radio while I am in a car."  24% of the respondents either "Completely agree" or "Somewhat agree" with this statement.  Among these people, we found that 29% of them chose 5 (="Always") for their attention level to radio advertising, and 43% of them chose 5 or 4.  These numbers are slightly lower than the general population.  So there are two pieces of good news --- one, radio advertisements can be effective; two, we are not in imminent danger from a population of distracted drivers out there.


De los programas


         Artículo 64.  Se entiende por programa cultural aquel que tienda a satisfacer las necesidades estéticas y formativas del público y elevar su condición espiritual. Estos programas estarán destinados a divulgar el arte en toda sus manifestaciones, la ciencia, la historia y en general toda clase de obras de creación. Podrán incluir el análisis, la crítica y la interpretación de estas obras.

         Artículo 65. En todo programa cultural deberán ser identificados claramente los nombres de las obras y de sus autores. Asimismo, deberá hacerse un bosquejo biográfico del autor y alguna mención crítica de la obra.

         Artículo 66. Se entiende por programa educativo aquel de carácter didáctico y con objetivos pedagógicos. Deberán ser diseñados en forma tal, que sean, fácilmente comprendidos por los oyentes y cumpla la finalidad que con ellos se persigue.

         Artículo 67. Se entiende por programa deportivo aquel que transmite o comenta eventos de esta naturaleza, estimula la afición por la cultura física y la práctica de los deportes. Igualmente los destinados a divulgar la historia de los deportes y de la cultura física y su conocimiento a favor de la salud y en general, todo lo concerniente a los deportes.

         Artículo 68. Se entiende por programa informativo aquel destinado a transmitir noticias y comentar sucesos o hechos nacionales o internacionales.

En dichos programas se deberá identificar el autor del texto de las noticias o comentarios. Cuando se lee una noticia aparecida en otro medio de comunicación, este deberá ser identificado.

         Artículo 69. Se entiende por programas infantiles los espacios estructurados exclusivamente con base en las vivencias de la niñez, y que contribuyan a su recreación favoreciendo el desarrollo de su propia experiencia sin detrimento de su condición de niño.

         Artículo 70. Las estaciones incluirán en su programación diaria un mínimo de:

1)   Dos horas de programas culturales.

2)   Noventa minutos de programas educativos.

3)   Una hora de programas informativos.

4)   Treinta minutos de programas deportivos.

Los programas que se refieren los numerales 1 y 2 serán transmitidos en el horario comprendido entre las ocho de la mañana y las ocho de la noche.

         Artículo 71. Los días sábado y domingo las estaciones transmitirán en el horario comprendido entre las ocho de la mañana y las seis de la tarde por lo menos una hora de programas dedicados exclusivamente  a la atención de los niños.

         Artículo 72. En las emisiones diarias comprendidas entre las siete de la mañana y diez de la noche, cada estación incluirá dentro de su programación musical, por lo menos, un cincuenta por ciento de música venezolana en sus diferentes manifestaciones.

         Artículo 73. Las estaciones de radiodifusión sonora en frecuencia modulada transmitirán el Himno Nacional y los Himnos Estatales en los términos establecidos en las Resoluciones del Ministerio de Transporte y Comunicaciones No 621 del 8 de agosto de mil novecientos ochenta y No 407 del veintisiete de julio de mil novecientos ochenta y dos, respectivamente.

         Artículo 74. Cada estación establecerá su horario de transmisión diaria, el cual, para entrar en vigencia, o ser modificado, requerirá la aprobación del Ministerio.


De la publicidad


         Artículo 75. En las estaciones educativas o culturales e radiodifusión sonora en frecuencia modulada sólo podrán transmitirse mensajes de patrocinio, entendiendo por tales aquellas menciones sobre cualquier firma, producto o servicio a cuyo nombre se presente algún programa.

         Artículo 76. El total del tiempo dedicado a la publicidad comercial por las estaciones no excederá de ocho minutos distribuidos en dos cortes por cada hora de transmisión incluyendo promociones de la estación. La estación deberá identificarse cada treinta minutos con los indicativos de llamada y frecuencia en MHz.

         Artículo 77. Los mensajes comerciales que se transmitan deberán tener una duración no menor de diez segundos ni mayor de cuarenta y cinco segundos.

         Artículo 78. Se prohibe la transmisión de publicidad comercial que interrumpa la secuencia lógica de un programa.

         Artículo 79. No se podrán transmitir mensajes comerciales que:

1)   Inciten a la especulación o engañen al público.

2)   Promuevan actividades ilícitas.

3)   Asocien el producto con temas contrarios a las buenas costumbres o a la educación del público.

4)   Hagan propagandas a productos, sustentadas en investigaciones cuyas conclusiones no hayan sido verificadas previamente por el Ministerio competente.

5)   No tengan la aprobación del organismo respectivo, cuando sea necesario.

         Artículo 80. En ningún caso podrán transmitirse mensajes comerciales de cigarrillos ni de bebidas alcohólicas.

         Artículo 81. La publicidad se emitirá con intensidad de voz, de música o de cualquier otro efecto de sonido, no superior al nivel normal utilizado en los programas.

         Artículo 82. En la redacción de los textos de publicidad deberán observarse las normas impuestas por la cultura, las buenas costumbres y el uso correcto del idioma castellano.

(posted by Roland Soong on 10/26/2000)

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