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FM Broadcasting Station Proposal (Name of the Station)
by
Randy J. Alarcon Keith Green F. Cabrera
Hanna Mae D. Cambronero Charlz F. Fontamillas Erickson D. Malate Jett-Rett S. Santos
Antipas T. Teologo Jr. Aaron M. Tiro
Kristine Jean Diane A. Virtudez Jay Lyn A. Yao
Electronics and Communications Engineering TIP, 2007
A Proposal Report Submitted to the Electronics and Communications Department in Partial Fulfillment of the Requirements for the Course Subject
Broadcasting Engineering and Acoustics
Technological Institute of the Philippines
September, 2007
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APPROVAL SHEET
This is to certify that we have read and examined the paper prepared by RANDY J. ALARCON, KEITH
GREEN F. CABRERA, HANNA MAE D. CAMBRONERO, CHARLZ F. FONTAMILLAS, ERICKSON
D. MALATE, JETT RETT S. SANTOS, ANTIPAS T. TEOLOGO Jr, AARON M. TIRO, KRISTINE JD
A. VIRTUDEZ, JAY LYN A. YAO entitled FM Broadcasting Station Proposal and hereby
recommend that it be accepted as fulfillment of the practicum requirement for the Course Subject
BROADCASTING ENGINEERING AND ACOUSTICS.
Panel Member 1 Panel Member 2
Committee Chair
This paper is hereby approved and accepted as a fulfillment of the requirement for the Course Subject
BROADCASTING ENGINEERING AND ACOUSTICS.
Engr. Antipas T. Teologo Jr.
Instructor, Broadcasting Engineering and
Acoustics
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TABLE OF CONTENTS
Approval sheet 22222222222222222.. 2
Table of contents 22222222222222222.. 3
Abstract ............................................................... 4
Chapter I: Introduction 22222222222222222.. 5
Chapter II: Review of Related Literature
A. Broadcast Bands 22222222222222222.. 6
B. Broadcast Bands around the World 22222222.. 7
C. Pre-emphasis and De-emphasis 22222222.. 7
D. FM Stereo 22222222222222222.. 8
E. Dolby FM 22222222222222222.. 9
F. Adoption of FM broadcasting worldwide 22222222.. 9
G. Microbroadcasting 22222222222222222..11
FM Broadcast Standards 22222222..12
Classes of Stations 22222222..12
FM Broadcast Frequency Allocation 22222222..13
Radio Frequency Protection Ratio (dB) ..14
FM Transmitter Considerations 22222222..14
FM Stereo Broadcasting 22222222..16
Broadcast Transmission Services 22222222..16
Chapter II: Methodology 22222222222222222..17
Chapter IV: Result and Discussion 22222222..19
Chapter V: Conclusion and Recommendation 22222222..22
Chapter VI: Appendices
a. FM KBP Manual 22222222222222222..23
b. FM Studio Layout 22222222222222222..77
c. Block Diagram for FM Radio 22222222..78
d. Glossary 22222222222222222..79
e. References 22222222222222222..82
f. Curriculum vitae 22222222222222222..85
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g. Pictures 22222222222222222..93
ABSTRACT
DZLA (DZ Logos Arithma) is an FM radio station operating at a frequency of
104.5 MHz. The location of its transmitter is at Tabuk, Kalinga with polar
coordinates of 1724 (Latitude) 12142 (Longitude).
Tabuk came from the word "Tobog", a living stream that runs from the upper
part of the municipality that flows down to the lower part of the town which waters
the wide fields of the residents of the place. Its land area accounts to 741.70
hectares with a total population of 76,788 as of 2005 NSO census.
It has 42 barangays with only 8 urban barangays. The main source of living is
farming due mainly to its wide tract of lands for agricultural production specially on
palay. In fact, Tabuk is dubbed as the rice granary or the bread basket of the
Cordillera.It has been also a consistent hybrid producer for the past two years.
Tabuk is a component city and capital of the province of Kalinga. According to
the 2000 census, it has a population of 78,633 people in 13,985 households.
Tabuk became the Cordilleras second city after Baguio and surpassed
Bangued, the capital of Abra province on June 23, 2007, when 17,060 voters ratified
Republic Act No. 9404, An Act Converting the Municipality of Tabuk into a
Component City of the Province of Kalinga to be Known as the City of Tabuk.
DZLA transmits a 5kW power with an ERP of 10kW. It has an Antenna Height
Above Average Terrain (HAAT) of 200 ft. with an antenna gain of 3.01dB.
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Chapter I: INTRODUCTION
In 1933, FM radio was patented by inventor Edwin H. Armstrong. FM uses
frequency modulation of the radio wave to minimize static and interference from
electrical equipment and the atmosphere, in the audio program. In 1937, W1XOJ,
the first experimental FM radio station, was granted a construction permit by the
FCC.
The first FM broadcasting stations were in the United States, but initially they
were primarily used to broadcast classical music to an upmarket listenership in
urban areas and for educational programming. By the late 1960s FM had been
adopted by fans of "alternative rock" music, but it wasn't until 1978 (the first year that
listenership to FM stations exceeded that of AM stations) that FM became
mainstream. During the 1980s and 1990s, Top 40 music stations and later even
country music stations largely abandoned AM for FM. Today AM is mainly the
preserve of talk radio, religious programming, ethnic (minority language)
broadcasting and some types of minority interest music. Ironically, this shift has
transformed AM into the "alternative band" that FM once was.
After World War II, the FM radio broadcast was introduced in Germany. In
1948, a new wavelength plan was set up for Europe at a meeting in Copenhagen.
Because of the recent war, Germany (which did not exist as a state and so was not
invited) was only given a small number of medium-wave frequencies, which are not
very good for broadcasting. For this reason Germany began broadcasting on UKW
("Ultrakurzwelle", i.e. ultra short wave, nowadays called VHF) which was not
covered by the Copenhagen plan. After some amplitude modulation experience with
VHF, it was realized that FM radio was a much better alternative for VHF radio than
AM. Because of this history FM Radio is still referred to as "UKW Radio" in
Germany. Other European nations followed a bit later, when the superior sound
quality of FM and the ability to run many more local stations because of the more
limited range of VHF broadcasts were realized.
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The radio frequency spectrum used for FM is from 88 MHz to 108 MHz and is
divided into 100 channels. Each channel has a band of frequency 200 kHz wide. The
channels for FM broadcast station starts at 88.1 MHz and ends at 107.9 MHz. The
FM broadcast station employs frequency modulation. Frequency modulation is a
system of modulation where the instantaneous frequency varies in proportion to the
instantaneous amplitude of the modulating signal, and the instantaneous radio
frequency is independent of the frequency of the modulating signal.
Broadcast stations in the Philippines are divided into classes. Class-A station
transmitter power must not exceed 25kW and an ERP not exceeding 125kW and
limited in HAAT of 2,000 ft. The minimum transmitter power shall be 10kW. Class-A
stations are only allowed in Metro-Manila and Metro-Cebu. Class-B station
transmitter power must not exceed 10kW and an ERP not exceeding 30kW with
HAAT of 500 ft. The minimum transmitter power shall be 1kW. A Class-C station is a
non-commercial, community station having an authorized ERP of 1,000 watts. A
Class-D station transmitter power must not exceed 10 watts. Educational stations
are under this class.
Chapter II. REVIEW OF RELATED LITERATURE
A. Broadcast Bands
The original FM broadcast band in the United States until 1946 was on 42 to
50 MHz with 0.2 MHz channel spacing. This band was abandoned after World War II
and is now allocated to fixed, mobile, and land mobile radio services.
The term "FM band" can upset purists, because it conflates a modulation
scheme with a range of frequencies. It is effectively shorthand for 'frequency band in
which FM is used for broadcasting'. The exact range of frequencies used varies
around the world, but always falls within the VHF part of the radio spectrum. The
term "VHF" was previously in common use for "FM" within the EU. ("UKW," which
stands for "Ultrakurzwellen" in German, meaning "ultra short wave", is still widely
used in Germany.).
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B. Broadcast Bands around the World
Throughout the world, the broadcast band is 87.5 to 108.0 MHz, or some
portion thereof. In the U.S. it is 87.8 to 108.0 MHz. Japan is the only exception,
using the 76 to 90 MHz band with 0.1 MHz channel spacing. In the former Soviet
republics, and some Eastern Bloc nations, an additional older band from 65.9 to 74
MHz is also used. Assigned frequencies are at intervals of 30 kHz. This band,
sometimes referred to as the OIRT band, is slowly being phased out in many
countries. The frequency of an FM broadcast station (more strictly its assigned
nominal centre frequency) is usually an exact multiple of 100 kHz. In most of the
Americas and the Caribbean, only odd multiples are used. In some parts of Europe,
Greenland and Africa, only even multiples are used. In Italy, "half-channel" multiples
of 50 kHz are used. There are other unusual and obsolete standards in some
countries, including 0.001, 0.01, 0.03, 0.074, and 0.3 MHz.
C. Pre-emphasis and De-emphasis
Random noise has a 'triangular' spectral distribution in an FM system, with
the effect that noise occurs predominantly at the highest frequencies within the
baseband. This can be offset, to a limited extent, by boosting the high frequencies
before transmission and reducing them by a corresponding amount in the receiver.
Reducing the high frequencies in the receiver also reduces the high-frequency
noise. These processes of boosting and then reducing certain frequencies are
known as pre-emphasis and de-emphasis, respectively. The amount of pre-
emphasis and de-emphasis used is defined by the time constant of a simple RC filter
circuit. In most of the world a 50 s time constant is used. In North America, 75 s is
used. This applies to both mono and stereo transmissions and to baseband audio
(not the subcarriers).
The amount of pre-emphasis that can be applied is limited by the fact that
many forms of contemporary music contain more high-frequency energy than the
musical styles which prevailed at the birth of FM broadcasting. They cannot be pre-
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emphasized as much because it would cause excessive deviation of the FM carrier.
(Systems more modern than FM broadcasting tend to use either programme-
dependent variable pre-emphasis, e.g., dbx in the BTSC TV sound system, or none
at all.). The problems with pre-emphasis due to the high frequency energy in modern
music can be greatly attenuated using psychoacoustics principles, as Oscar Bonello
demonstrates in his March 2007 AES paper. A new device, the IM cancelled high
frequency clipper, is able to produce heavy audio clipping at high audio frequencies,
with low listener fatigue.
D. FM Stereo
In the early 1960s, several systems to add stereo to FM radio were
considered by the FCC, including one submitted by E. H. Armstrong, the inventor of
FM, which avoided many of the problems with the Zenith-GE pilot tone multiplex
system. The Armstrong system was rejected by the FCC because it did not allow
sub-carrier services, and the Zenith system has become the standard method in
most countries.
It is important that stereo broadcasts should be compatible with mono
receivers. For this reason, the left (L) and right (R) channels are matrixed into sum
(M) and difference (S) signals, i.e. M = (L+R)/2 and S = (LR)/2. A mono receiver
will use just the M signal. A stereo receiver will matrix the M and S signals to recover
L and R: L = M+S and R = MS.
The M signal is transmitted as baseband audio in the range 30 Hz to 15 kHz.
The S signal is amplitude-modulated onto a 38 kHz suppressed carrier to produce a
double-sideband suppressed carrier (DSBSC) signal in the range 23 to 53 kHz.
A 19 kHz pilot tone, at exactly half the 38 kHz subcarrier frequency and with a
precisely defined phase relationship to it, is also generated. This is transmitted at 8-
10% of overall modulation level and used by the receiver to regenerate the 38 kHz
subcarrier with the correct phase.
The final multiplex signal from the stereo generator is the sum of the
baseband mono audio (M), the pilot tone, and the DSBSC subcarrier. This multiplex,
along with any other subcarriers, modulates the FM transmitter.
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Converting the multiplex signal back to left and right is performed by a stereo
decoder, which is built into stereo receivers.
In order to preserve stereo separation, it is normal practice to apply pre-
emphasis to the left and right channels before matrixing, and to apply de-emphasis
at the receiver after matrixing.
Stereo FM signals are far more susceptible to noise and multipath distortion
than mono FM signals. This is due to several factors, including the following:
the addition of the two sidebands of the difference subcarrier to the
baseband signal increases the noise bandwidth of the signal by a
factor of three (9.5 dB) as compared with a mono signal.
as mentioned above, the pre-emphasis is applied to the audio signals
before encoding. This results in the pre-emphasis acting in the wrong
direction on the lower sideband of the difference subcarrier, i.e.
decreasing the level as the frequency rises, which will have a further
deleterious effect on the S/N of the difference signal.
For this reason many FM stereo receivers include a stereo/mono switch to
allow listening in mono when reception conditions are less than ideal, and most car
radios are arranged to reduce the separation as the S/N ratio worsens, eventually
going to mono while still indicating a stereo signal is being received.
In addition, the reception of vertically and horizontally polarised signals at
different phase relationships from the same transmitter site will further corrupt stereo
reception and invoke an earlier resolution within the receiver to mono presentation.
A short lived quadraphonic version of the Zenith-GE system used an
additional subcarrier at 76 kHz.
E. Dolby FM
A commercially unsuccessful noise reduction system used with FM radio in
some countries during the late 1970s, Dolby FM used a modified 25 s pre-
emphasis time constant and a frequency selective companding arrangement to
reduce noise. See: Dolby noise reduction system.
F. Adoption of FM broadcasting worldwide
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Despite having been developed in the 1940s, FM broadcasting took a long
time to be adopted by the majority of radio listeners.
The first FM broadcasting stations were in the United States, but initially they
were primarily used to broadcast classical music to an upmarket listenership in
urban areas and for educational programming. By the late 1960s FM had been
adopted by fans of "alternative rock" music, but it wasn't until 1978 (the first year that
listenership to FM stations exceeded that of AM stations) that FM became
mainstream. During the 1980s and 1990s, Top 40 music stations and later even
country music stations largely abandoned AM for FM. Today AM is mainly the
preserve of talk radio, religious programming, ethnic (minority language)
broadcasting and some types of minority interest music. Ironically, this shift has
transformed AM into the "alternative band" that FM once was.
Belgium, the Netherlands, Denmark and particularly West Germany were
among the first countries to adopt FM on a widespread scale. Among the reasons for
this were:
1. The medium wave band in Western Europe is heavily overcrowded,
leading to severe interference problems and, as a result, most MW frequencies are
suitable only for speech broadcasting.
2. Particularly in Germany after World War II, the best available medium wave
frequencies were used by the Allied occupation forces both for broadcasting
entertainment to their troops and for broadcasting cold war propaganda across the
Iron curtain
The regional structure of German broadcasting meant that the few remaining
AM frequencies available for civilian domestic broadcasting fell far short of the
number required and the broadcasters looked to FM as an alternative
Public service broadcasters in Ireland and Australia were far slower at
adopting FM radio than those in either North America or continental Europe.
However, in Ireland several unlicenced commercial FM stations were on air by the
mid-1980s. These generally simulcast on AM and FM.
In the United Kingdom, the BBC began FM broadcasting in 1955, with three
national networks carrying the Light Programme, Third Programme and Home
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Service (renamed Radio 2, Radio 3 and Radio 4 respectively in 1967). These three
networks used the sub-band 88.0 - 94.6 MHz. The sub-band 94.6 to 97.6 MHz was
later used for BBC and local commercial services. Only when commercial
broadcasting was introduced to the UK in 1973 did the use of FM pick up in Britain.
With the gradual clearance of other users (notably Public Services such as police,
fire and ambulance) and the extension of the FM band to 108.0 MHz between 1980
and 1995, FM expanded rapidly throughout the British Isles and effectively took over
from LW and MW as the delivery platform of choice for fixed and portable domestic
and vehicle-based receivers.
In addition, Ofcom (previously the Radio Authority) in the UK issues on
demand Restrictive Service Licences on FM and also on AM (MW) for short-term
local-coverage broadcasting which is open to anyone who does not carry a
prohibition and can put up the appropriate licensing and royalty fees. In 2006 almost
500 such licenses were issued.
FM started in Australia in 1947 but did not catch on and was shut down in
1961 to expand the television band. It was not reopened until 1975. Subsequently, it
developed steadily until in the 1980s many AM stations transferred to FM because of
its superior sound quality. Today, as elsewhere in the developed world, most
Australian broadcasting is on FM - although AM talk stations are still very popular.
Most other countries expanded their use of FM through the 1990s. Because it
takes a large number of FM transmitting stations to cover a geographically large
country, particularly where there are terrain difficulties, FM is more suited to local
broadcasting than national networks. In such countries, particularly where there are
economic or infrastructural problems, "rolling out" a national FM broadcast network
to reach the majority of the population can be a slow and expensive process.
G. Microbroadcasting
Low-power transmitters such as those mentioned above are also sometimes
used for neighborhood or campus radio stations, though campus radio stations are
often run over carrier current. This is generally considered a form of
microbroadcasting. As a general rule, enforcement towards low-power FM stations is
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stricter than AM stations due to issues such as the capture effect, and as a result,
FM microbroadcasters generally do not reach as far as their AM competitors
A. FM Broadcast Standards
Parameters Philippine Standards
Frequency Band 88 -108 MHz
No. of Channels 25
Bandwidth per Channel 200 kHz
Permitted Bandwidth 240 kHz (monophone)
Channel Spacing 800 kHz
Center Frequency Stability 2 kHz
Baseband Frequency 50 - 15000 Hz
Type of Modulation FM
Type of Emission F3E
Guardband 25 kHz above Upper Side Band
25 kHz below Lower Side Band
Frequency Deviation 75 kHz (for 100% modulation)
Pre-Emphasis 75us time constant
Pilot Subcarrier 19 kHz
Antenna Polarization Horizontal or circularly-polarized
Type of Receiver Superheterodyne
Intermediate Frequency 10.7 MHz
B. Classes of Stations
Stations Authorized Power
Class A Not exceeding 15 kW
Class B Not exceeding 10 kW
Class C Not exceeding 1 kW
Class D Not exceeding 10 W
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C. FM Broadcast Frequency Allocation
FMn = FM1 + (n 1)BW (MHZ)
Where: FM = Chanel Frequency in MHz FM1= Frequency in the 1
st FM Channel (88.1MHz) n =Channel number BW = Channel Bandwidth (200kHz) Philippine Major Cities Frequency Assignments
Channel No. Frequency (MHz)
FM2 88.3
FM6 89.1
FM10 89.9
FM14 90.7
FM18 91.5
FM22 92.3
FM26 93.1
FM30 93.9
FM34 94.7
FM38 95.5
FM42 96.3
FM46 97.1
FM50 97.9
FM54 98.7
FM58 99.5
FM62 100.3
FM66 101.1
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FM70 101.9
FM74 102.7
FM78 103.5
FM82 104.3
FM86 105.1
FM90 105.9
FM94 106.7
FM98 107.5
D. Radio Frequency Protection Ratio (dB)
Freq Monophonic Stereophonic
Spacing Steady Tropospheric Steady Tropospheric
(kHz) Interference Interference Interference Interference
0 36 8 45 37
25 31 12 51 43
50 24 16 51 43
75 16 22 45 37
100 12 27 33 25
150 8 28 18 14
200 6 6 7 7
250 2 2 2 2
300 -7 -7 -7 -7
350 -15 -15 -15 -15
400 -12 -20 -20 -20
E. FM Transmitter Considerations
1. Construction
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The transmitter shall be constructed either on racks and panels or
in totally enclosed frames protected as required by the Philippine
Electronics Code and the Philippines Electrical Code.
2. Enclosure
The transmitter shall be enclosed in the metal frame or grille
separated from the operating space by a barrier or other equivalent
means.
3. Grounding of Controls
All external metallic handles and controls accessible to the
operating personnel shall be effectively grounded.
No circuit in excess of 150 V shall have any part exposed to direct
contact.
4. Interlocks
All access doors shall be provided with interlocks which will
disconnect all voltage sin excess of 350 V when any access door is
opened.
5. Bleeder Resistor
Proper bleeder resistor or other automatic means shall be installed
across all capacitor banks to lower any voltage which may remain
accessible with access door open, to less than 350 V within 2
seconds after the access door is opened.
6. Wiring and Shielding
Wiring between units of the transmitter, with the exception of
circuits carrying radio frequency energy, shall be installed in
conduits of fiber or metal raceways for protection from mechanical
injury.
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All instruments having one more than 1,000 v potential to ground
shall be protected by a cage or cover.
F. FM Stereo Broadcasting
Two audio channels (L and R) are mixed to provide two new signals. The
first is the sum of the two input channels (L+R), and the second is the
difference of the two (L-R).
The sum channel (L+R) is modulated directly n the baseband assignment
between 50 and 15 kHz.
The difference signal (L-R) is DSBSC modulated in the 23 to 53 kHz slot
about a stereophonic Subarrier of 38 kHz.
Some FM stations are frequency division multiplexing an additional
channel on their carrier for the purpose of providing background music for
public buildings, a system licensed as
Subsidiary Communications Authorization (SCA)
Parameters Philippine Standards
Pilot Subcarrier 19 kHz 2Hz
Stereophonic Subcarrier 38 kHz (2nd harmonic of Pilot Subcarrier)
Stereophonic Subcarrier suppression
level
< 1% modulation of the main carrier
G. Broadcast Transmission Services 1. Studio-to-transmitter Link (STL) stations in this service are to be used for relay of aural programming materials from studio to transmitter and between fixed facilities in other locations.
STL Frequency Band Allocation
Band Frequency (MHz)
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Band A 310 315
Band B 734 752
860 880
942 - 953
2. Remote Pickup Broadcast Stations stations in this service are to be used for
the transmission of aural programming materials and associated cues and data.
Remote Pickup Band Allocation
Band Frequency (MHz)
Band A 305 310
Band B 450 451
Band C 455 - 456
3. Communications, Coordination, and Control Links
Band Allocation
Band Frequency (MHz)
Band A 4 -12
Band B
Band C
26.10 26.48
162.235 162.615
166.250
170.150
Band D 880 - 890
Chapter III. METHODOLOGY
In designing a broadcasting station, these procedures must be followed:
1. Assign a frequency ranging from 88.3 MHz to 107.9 MHz to be used by
your broadcasting station.
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2. Specify the antenna height above average terrain (HAAT), the effective
radiated power (ERP), the transmitted power and the location of the station (choose
a province with no station above or below 800kHz of your channel frequency).
3. List all the Co-channels, 1st Adjacency channels and 2nd Adjacency
channels with their corresponding ERP and locations.
4. Using the FM Contour Chart and a slider (used when the ERP is more than
1kW), locate the ERP of the each channels in the slider and place it on the center
line (or on the 40dB field strength line) parallel to the HAAT of your station.
5. Draw a horizontal line corresponding to this dBu field strength (for co-
channels use 60 dBu and 15 dBu, for 1st adjacency channels use 60 dBu and 53
dBu and for 2nd adjacency use 60 dBu and 80 dBu).
6. From the intersection of the two straight lines, determine which distance
curve the intersection coincides with. Since the distance is in miles, convert it to
kilometers.
7. Get the scale of your map (in this project, the scale is 0.058 cm for every
kilometer) and convert your distances to cm. The distance of the stations is their
corresponding radius in the map.
8. Locate each station in the map and plot their corresponding field strength in
dBu (15, 53, 60 and 80) according to the computed radius.
9. Compute for the Aggregate and distance of the stations to your station
location.
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Chapter IV. RESULTS AND DISCUSSION
PREDICTION OF SERVICE AREA AND OF INTERFERENCE
FM RADIO BROADCAST STATION (CALL SIGN): DZLA FREQUENCY: 104.5 MHz
LOCATION OF TRANSMITTER: TABUK, KALINGA POLAR COORDINATES: 1724 (Latitude) 12142 (Longitude)
TRANSMITTER POWER: 5kW ERP: 10kW ANTENNA HEIGHT: 200 ft. ANTENNA GAIN: 3.01 dB
EXTENT OF FIELDS IN KILOMETERS
80 dBu 60 dBu 53 dBu 15 dBu
10 mV/m 1 mV/m 446 uV/m 5.62 uV/m
8.53 25.75 37.01 214.04
BASIC CONSIDERATIONS:
1. Application for FM BROADCAST AUTHORIZATION must show two field strength contours, these are the 48 dBu
(251 uV/m) and the 60 dBu (1 mV/m) contours.
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2. THE ALLOCATION PROTECTION RATIOS FOR FM BROADCAST ARE AS FOLLOWS:
FREQUENCY FREQUENCY RF SIGNAL RATIO
RF PROTECTION
ADJUSTMENT SEPARATION RATIO (dB)
CO CHANNEL 0 6O dBu : 53 dbu 45 1mV / m : 0.45.62 uV / m
FIRST ADJACENCY 200kHz 6O dBu : 15 dbu 7 (LOWER OR UPPER) 1mV / m : 0.466 mV / m
SECOND ADJACENCY
400kHz 6O dBu : 80 dbu -20
(LOWER OR UPPER) 1mV / m : 10 mV / m
3. In predicting the distance to the field strength contours (EXTENT OF FIELDS) F (50,50) FM CHANNELS FIELD
INTENSITY CHART (FCC) maybe used. The chart is based on an ERP of 1 kW. For other values of ERP, the
accompanying sliders shall be used. The distance in miles obtained from use of the chart is converted to kilometers.
4. INTERFERENCE IS IMMINENT, when the aggregates sum of the EXTENT OF FIELDS of two stations (based on
their frequency separation and RF protection ratio is greater than the physical distance between these two stations.
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Chapter V. Conclusion and Recommendation
As a class B station operating at 10 kW ERP, DZLA has a high potential of
becoming a prominent FM station at Tabuk Kalinga.
Aside the from the proper selection of its frequency that enables the station to
avoid interference with other stations it is located in a place wherein it can have a full
capacity of transmitting the signal to various places since the place is actually feasible.
Only few will be wasted since the location of the stations transmitter is located in the
middle of Luzon and compared with other nearby stations, it has higher ERP which
gives an advantage over its competitors.
The station, following all the standards set by the National Telecommunications
Commission (NTC) and KBP, could be somehow seen as a giant FM station after five
years and we, the Logos Arithma Inc., as the proponent of this design, strongly
recommend our proposed FM radio station.
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Chapter VI. Appendices
a. FM KBP Manual
FM BROADCASTING STANDARDS
1. INTRODUCTION
The increasing importance of the role of FM broadcasting in the Philippines has
encouraged broadcast engineers and the National Telecommunications Commission to
pool their resources together and come up with technical standards and rules and
regulations relating to FM broadcast.
These technical standards and regulations were derived from CCIR
recommendations, relevant engineering data and rules and regulations of the Federal
Communication Commission, and other data supplied by manufacturers of radio
equipment and by licensees of FM broadcast stations. These standards and regulations
shall be revised from time to time to be effective and compatible with technical progress.
2. DEFINITION OF TERMS
2.1 FM broadcast band
That portion of radio frequency spectrum from 88MHz to 108 MHz. The band
is divided into 100 channels.
2.2 FM broadcast channel
A band of frequencies 200 kilohertz wide and I designated by its center
frequency. Channels of FM broadcast stations begin at 88.1 megahertz and
continue in successive steps of 200 kilohertz to and including 107.9 megahertz.
2.3 FM broadcast station
A station employing frequency modulation in the FM broadcast band and
intended to be received by the general public.
2.4 Frequency modulation
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A system of modulation where the instantaneous frequency varies in proportion
to the instantaneous amplitude of the modulating signal, and the instantaneous
radio frequency is independent of the frequency of the modulating signal.
2.5 Center frequency
The carrier frequency allocated by the Authority.
2.6 Frequency Swing
The instantaneous departure of the frequency of the emitted wave from the
center frequency resulting from modulation.
2.7 Antenna height above average terrain (HAAT) means
a. The height of the radiation center of the antenna above the terrain 3 to
16 kilometers from the antenna. (Generally, a different antenna height will
be determined for each radial direction from the antenna. The average of these
various heights is considered as the antenna height above average terrain).
b. Where circular or elliptical polarization is employed the antenna height
above the average terrain shall be based upon the height of the radiation center
of the antenna which transmits the horizontal components of radiation.
2.8 Antenna field gain
The ratio of the effective free space field intensity produced at 1.6 kilometers
in the horizontal plane expressed in millivolts per meter for one (1) kilowatt
antenna input power, to 137.6 millivolts per meter.
2.9 Antenna power gain
The square of the ratio of the root mean-square free space field strength
produced at 1.6 kilometers in the horizontal plane, in milivolts per meter for one
(1) kilowatt antenna power, to 137.6 milivolts per meter. This ratioshould be
expressed in decibels (dB). (If specified for a particular direction, antenna power
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gain is based on the field strength in that direction only).
2.10 Effective radiated power (ERP)
The product of the transmitted power ( transmitter output power les
transmission line loss) multiplied by (a) the antenna power gain or (b) the
antenna field gain squared. Where circular or elliptical polarization is employed ,
the term effective radiated power is applied separately to the horizontal and
vertical components of radiation.
2.11 Field intensity
Field intensity as used in these standards shall mean the electric field
intensity in the horizontal direction.
2.12 Free space field intensity
The field intensity that would exist at a point in the absence of waves reflected
from the earth or other reflecting objects.
2.13 Service area
As applied to FM broadcasting, means the service resulting from an assigned
effective radiated power and antenna height above average terrain.
2.14 Radio-frequency (RF) Protection Ratio
The value of the radio-frequency wanted-to-interfering signal ratio that
enables, under specified conditions, the radio-frequency protection ratio to be
obtained at the output of a receiver.
2.15 Percentage modulation
The ratio of the actual frequency swing to the frequency swing defined as
100 percent modulation, expressed in percentage. For FM broadcasting stations,
a frequency swing +75 kilohertz is defined as 100 percent modulation.
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2.16 Multiplexing
In its simplest sense, multiplexing implies that two or more independent
sources of information are combined for carriage over a single medium, namely,
the radio frequency carrier, and then are separated at the receiving end. In
stereophonic broadcasting , for example, program information consisting of left
and right audio signal are multiplexed onto an FM carrier for transmission to
receivers which subsequently recover the original audio signals.
2.17 FM Stereophonic Broadcast
The transmission of a stereophonic program by a single FM broadcast
station utilizing the main channel and a stereophonic sub-channel.
2.18 Channel
A transmission path. The distinction between the concept of a Channel and
a signal are not always clear. The usage herein distinguishes between
transmission channels; e.g., main channel, stereophonic subchannel, etc., and
left and right audio signal.
2.19 Composite Baseband signal
A signal which is the sum of all signals which frequency-modulates the main
carrier. The signal can be represented by a formula which includes all signal
components: the main channel signal, the modulated stereophonic subchannel,
the pilot subcarrier and the SCA subcarrier(s).
2.20 FM Baseband
The frequency band from 0 Hertz (Hz) to a specified upper frequency which
contains the composite baseband signal.
2.21 Main Channel
The band frequencies from 50 (or less) Hz to 15,000 Hz on the FM baseband
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which contains the main channel signal.
2.22 Main Channel Signal
A specified combination of the monophonic or left and right audio signals
which frequency-modulates the main carrier.
2.23 Stereophonic Sound
The audio information carried by plurality of channel arranged to afford the
listener a sense of spatial distribution of sound sources. Stereophonic sound
includes, but is not limited to, biphonic (two channel), triphonic (three channel)
and quadraphonic (four channel) services.
2.24 Stereophonic Sound Subcarrier
A subcarrier within the FM broadcast baseband used for transmitting signals
for stereophonic sound reception of the main broadcast program service.
2.25 Stereophonic sound Subcarrier
The band of frequencies from 23 KHz to 99 KHz containing sound
subcarriers and their associated sidebands.
2.26 Subchannel
A transmission path specified by a subchannel signal occupying a specified
band of frequencies.
2.27 Subchannel Signal
Subcarrier(s) and associated sideband(s) which frequency-modulate the
main carrier. It is synonymous with subcarrier, as in the stereophonic subcarrier
or SCA subcarrier.
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2.28 Pilot Sub-carrier
A pilot sub-carrier serving as a control signal for use in the reception of FM
stereophonic broadcast.
2.29 Left (or Right) signal
The electrical output of a microphone or a combination of microphones
placed so as to convey the intensity, time, and location of sounds originating
predominantly to the listeners left (or right) of the center of the performing area.
2.30 Left (or Right) stereophonic channel
The left (or right) signal as electrically reproduced in the reception of an
stereophonic broadcast.
2.31 Stereophonic separation
The ratio of the electrical signal caused in the right (or left) stereophonic
channel, to the electrical signal caused in the left (or right) stereophonic channel,
by the transmission of only a right (or left) signal.
2.32 Frequency Deviation
The peak difference between the instantaneous frequency of the
modulated wave and the carrier frequency.
2.33 Injection Ratio
The ratio of the frequency swing of the FM carrier by a subchannel signal
to the frequency swing defined as 100 percent modulation, expressed in
percentage. The total injection of more than one subchannel signal is the
arithmetic sum of each subchannel.
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2.34 Cross-talk
An undesired signal occurring in one channel caused by an electrical
signal in another signal.
2.35 Linear Crosstalk
A form of crosstalk in which the undesired signal(s) is created by phase
or gain inequalities in another channel or channels. Such crosstalk may be due to
causes external to the stereophonic generator; consequently it is sometimes
referred to as system crosstalk.
2.36 Nonlinear Crosstalk
A form of crosstalk in which the undesired signal(s) is created by harmonic
distortion or intermodulation of electrical signal(s) in another channel or channels.
Such crosstalk may be due to distribution within the stereophonic generator or
FM transmitter; consequently it is sometimes referred to as transmitter
crosstalk.
2.37 SCA
The term SCA is an acronym for a subsidiary Communication Authority.
2.38 Index of Cooperation
As applied to facsimile broadcasting, is the product of the number of lines
per inch, the available length in inches, and the reciprocal of the line use ratio
(e.g. 105 x 8.2 x 8/7 = 984).
2.39 Line-use ratio
As applied to facsimile broadcasting is the ratio of available line to the total
length of scanning line.
2.40 Available line
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Means the portion of the total length of scanning line that can be used
specially for picture signals.
2.41 Rectilinear scanning
The process of scanning an area in a predetermined sequence of narrow
straight parallel strips.
2.42 Optical density
The logarithm (to the base 10) of the ratio of incident to transmitter or
reflected light.
2.43 Experimental period
The period between 12 midnight to 5:00 a.m. local standard time (1600-
2100 GMT). This period may be used for experimental purposes in testing and
maintaining apparatus by the licensee of any FM broadcast station on its
assigned frequency and not in excess of its authorized power, provide no
interference is caused to other station maintaining a regular operating schedule
within such period.
2.44 Operating Power
This is the product of the plate voltage (Ep) and the plate current ( Ip) of
the last ratio stage and efficiency factor, F, expressed: Operating power =Ep x
Ipx F. This is the indirect method of determining the operating power of each
FM station for the purpose of specifying the operating power range of FM
transmitters. The factor F shall be established by the transmitted manufacturer
for each type of transmitter and shall be specified in the instruction book (s)
supplied to each customer with each transmitter.
2.45 Last radio stage
The oscillator of radio-frequency-power amplifier stage which supplies
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power to the antenna.
2.46 Qualified technician
As applied to FM broadcasting means a person who is a holder of any
class of radio Telephone Operators License or its equivalent except those
mention in Section 7.4 as issued by the existing regulatory body.
3. ALLOCATION OF FREQUENCY FOR FM BROADCAST STATION (See Table 1.)
4. CLASSES OF FM BROADCAST STATIONS.
4.1 Class-A Stations
A class-A station shall have an authorized transmitter power not
exceeding 25 kilowatts and an Effective Radiated Power (ERP) not exceeding
125 kilowatts and limited in antenna height of 2,000 feet above average terrain.
The minimum transmitter Power shall be 10 KW.
Class-A station shall only be allowed in Metro-Manila and Metro-Cebu.
4.2 Class-B station
A Class-B station shall have an authorized transmitter power not
exceeding 10 kilowatts and an Effective Radiated Power not exceeding 30
kilowatts, and limited in antenna height of 500 feet above average terrain. The
minimum transmitter power shall be 1 KW.
4.3 Class-C station
A Class-C station is a non-commercial, community station having an
authorized radiated power not exceeding 1,000 watts (ERP).
4.4 Class-D station
A class-D station shall an authorized transmitter power not exceeding 10
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watts.
Educational station shall be allowed to operate with Class-D transmitter power.
4.5 All classes of FM station shall be protected to the 1 mV/m cotour or 60 dBU
contour.
4.6 Table of Assignments
The frequency assignment for the cities of Manila, Laoag, Legaspi, Cebu,
Davao and Zamboanga shall be selected from table 2.
Table 2
Channel No. Frequency (mHz)
202 88.3
206 89.1
210 89.9
214 90.7
218 91.5
222 92.3
226 93.1
230 93.9
234 94.7
238 95.5
242 96.3
246 97.1
250 97.9
254 98.7
258 99.5
262 100.3
266 101.1
270 101.9
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274 102.7
278 103.5
282 104.3
286 105.1
290 105.9
294 106.7
298 107.5
4.7 Radio frequency Protection Ratios
4.7.1 The following radio frequency protection ratios (Table 3) provide for
the minimum physical separation between stations and protection of stations
from Interference.
RADIO-FREQUENCY PROTECTION RATIOS (dB)
(based on the horizontal component of radiation)
____________________________________________
Frequency
Spacing R.F. Signal Ratio
(kHz)
____________________________________________
0 60 dBu : 15 dBu
200 60 dBu : 53 dBu
400 60 dBu : 80 dBu
4.7.2 Intermediate frequency amplifiers of most FM broadcast receivers
are design to operate on 10.7 megaHertz. For this reason the assignment of two
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stations in the same area, one with a frequency 10.6 or 10.8 mega-
Hertz removed from that of the other, should be avoided if possible.
4.7.3 FM Broadcast Stations, shall not be authorized to operate in the same city
or in nearby cities with a frequency separation of less than 800 kHz.
4.7.4 The nature and extent of the protection from interference accorded the FM
stations is limited solely to that which results from the application of the radio
frequency protection ratio.
4.7.5 A commercial broadcast entity may establish only one primary FM radio
station within the geographical boundaries of any province.
5 TECHNICAL REQUIREMENTS
5.1 Safety Requirements
5.1.1 Conformity with Electrical Wiring Rules
All equipment using electrical power shall conform with the
provisions of the Philippine Electrical Code and the Philippines Electronics
Code so as to ensure the safety of property, equipment, and personnel
and the public in general.
5.1.2 All component parts shall be in accordance with generally accepted
standards or those of the International Standards.
5.2 Transmitting Facilities
5.2.1 Location and Layout
a. Any site particularly suitable for FM broadcasting in an area, in
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the absence of other comparable sites, may be shared by and be
made available to as many applicants as possible.
b. The transmitting site should be selected consistent with
purpose of the station, i.e., whether it is intended to serve a small
city, a metropolitan area, or a large region. The location should be
so chosen that line-of-sight can be obtained from the antenna over
the principal city or cities to be served.
5.2.2 Antenna System
a. It shall be standard to employ horizontal polarization. However
circular or elliptical polarization of the clockwise or counter-
clockwise rotation may be employed, if so desired.
b. The antenna must be constructed such that it is clear of
surrounding buildings or objects that would cause shadow
problems.
c. In the event a common tower is issued by two or more
licensees for antenna and / or antenna supporting purposes, the
licensee who owns the tower shall assume full responsibility for the
maintenance of the tower structure, its painting and lighting
requirements. In case of shared ownership, only one licensee shall
assume such responsibility.
For the protection of air navigation, the antenna and
supporting structure shall be painted and illuminated in
accordance with ATO regulations.
5.2.3 Transmitter and Association Equipment
a. Electrical Performance Standards
The general design of the FM broadcast transmitting system
(from input terminal of the microphone preamplifier, through audio
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facilities at the studio through lines or other circuits between studio
and transmitter, through audio facilities at the transmitter, but
excluding equalizers for the correlation of deficiencies in
microphone response shall be in accordance with the following
principles and specifications:
1) The transmitter shall operate satisfactorily in the
operating power range with a frequency swing of + 75 kiloHertz,
which is defined as 100 percent modulation.
2) The transmitting system shall be capable of transmitting a
band of frequencies from 50 to 15,000 Hertz. Pre-emphasis shall
employed in accordance with the impedance-frequency
characteristics of a series inductance-resistance network havinga
time constant of 75 microseconds (See Annex Fig. 2). The
deviation of the system response from the standard pre-emphasis
curve shall lie between two limits. The upper of these limits shall be
uniform: (no deviation) from 50 to 15,000 Hertz. The lower the limit
shall be uniform from 100 to 7,500 Hertz and 3 db the upper limit;
from 50 to 100 Hertz and the lower limit shall fall from the 3 db limit
at a uniform rate of 1 db per octave (4 db at 50 Hertz); from 7,500
to 15,000 Hertz, the lower limit shall fall from the 3 dB limit at a
uniform rate of 2 dB per octave (5 dB at 15,000 Hertz).
3.) At any modulating frequency between 50 and 15,000
Hertz and at modulation percentages of 25, 50 and 100 percent
combined audio frequency harmonics measured in the output of the
system shall not exceed the root-mean-square values given in the
following table:
Modulating
Frequency Distortion
50 to 100 Hz2222..3.5%
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100 to 7,500Hz222...2.5%
7,500 to 15,000 Hz22.3.0%
4) Measurements shall be made employing a 75
microsecond de-emphasis in the measuring equipment and 75
microsecond pre-emphasis in the transmitting equipment, and
without compression, if a compression amplifier is employed.
Harmonics shall be included to 30,000 Hertz.
5) It is recommended that none of the three main divisions
of the system (transmitter, studio to transmitter circuit, and audio
facilities) contribute over one-half of these percentage since at
some frequencies the total distortion may be come the arithmetic
sum of the distortion of the divisions.
6) The transmitting system output noise level (frequency
modulation) in the band of 50 to 15,000 Hertz shall be at least
60decibels below 100 percent modulation (frequency swing + 75
kilohertz).
The measurement shall be made using 400 Hertz modulation
as a reference. The noise measuring equipment shall be provided
with standard 75 microsecond de-emphasis; the ballistic
characteristic of the instrument shall be similar to those of the
standard VU meter.
7) The transmitting system output noise level (amplitude
modulation) in the band of 50 to 15,000 Hertz shall be least 50
decibels below the level representing 100 percent modulation. The
noise-measuring equipment shall be provided with a standard 75
microsecond de-emphasis; and the ballistic characteristics of the
instrument shall be similar to those of the standard VU meter.
8) Automatic means shall be provided in the transmitter to
maintain the assigned center frequency within the allowable
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tolerance of (+ 2000 Hertz).
9) The transmitting shall be equipped with suitable
indicating instruments for the determination of operating power and
with other instruments as are necessary for proper adjustment,
operation, and maintenance of the equipment.
10) Adequate provision shall be made for varying the
transmitter output power to compensate for excessive variation in
the line voltage or for others factors affecting the output power.
11) Allowances shall be provided in all component part to
avoid overheating at the rated maximum output power.
12) If a limiting or compression amplifier is employed,
precaution should be maintained in its connection in the circuit due
to the use of pre-emphasis in the transmitting system.
13) Any emission appearing on a frequency removed from
the carrier by between 120 kHz, and 240 kHz, inclusive, shall be
attenuated at least 25 decibels below the level of the un-modulated
carrier.
14) Any emission appearing on a frequency removed from
the carrier by more than 240 kHz and up to and including 600 kHz
shall be attenuated at least 35 db below the level of the
unmodulated carrier.
15) Any emission appearing on a frequency removed from
the carrier by more than 600 kHz shall be attenuated at least 43
+10 Log10 ( Power, in watts ) decibels below the level of the
unmodulated carrier, or 80 decibels, whichever is the lesser
attenuation.
b. Construction
In general, the transmitter shall be constructed either on
rocks and panels or in totally en-closed frames protected as
required by the Philippine Electronics Code and the Philippine
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Electrical Code and those set forth below:
The transmitter shall comply with the following:
1) Enclosure. The transmitter shall be enclosed in a metal
frame or separated from the operating space by a barrier or other
equivalent means. All metallic parts shall be connected to ground.
2) Grounding of controls. All external metallic handles and
controls accessibility to the operating personnel shall be effectively
exposed to direct contact. A complete dead front type of switch-
board is preferred.
3) Interlocks on doors.
a) All access doors shall be provided with interlocks which
will disconnect all voltages in excess of 350 volts when any access
door is opened.
b) Means shall be provided for making all tuning
adjustment, requiring voltages in excess of 350 volts to be applied
to the circuit, from the front of the panels with all access doors
closed.
c) Proper bleeder resistor or other automatic means shall
be installed across all capacitor banks to lower any voltage which
may remain accessible with access door open to less than 350
volts within 2 seconds after the access door is opened.
d) All plate supply and other high voltage equipment,
including transformer, filters, rectifiers and motor generator, shall be
protected so as to prevent injury to operating personnel.
e) Power equipment and control panel of the transmitter
shall meet the above requirements exposed 220 volts AC switching
equipment on the front of the power control panel is not
recommended.
c. Wiring and Shielding
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1) The transmitter panels or units shall be wired in
accordance with standard switchboard practice, either with
insulated leads properly cabled and supported or with rigid bus bar
properly insulated and protected.
2) Wiring between units of the transmitter, with the exception
circuits carrying radio-frequency energy, shall be installed in
conducts or approved fiber or metal raceways for protection from
mechanical injury.
3) Circuits carrying radio-frequency energy between units
shall be coaxial, or two-wire balanced lines, or properly shielded.
4) All stages or units shall be adequately shielded and
filtered to prevent interaction and radiation.
d. Metering equipment
1) All instruments having more than 1,000 volts potential to
ground on the movements shall be protected by a cage or cover.
(some instruments are designed by the manufacturer to operate
safely with voltages in excess of 1,000 volts on the movement).
2) In case the plate voltmeter is located on the low potential
side of the multiplier resistor with the potential of the high potential
terminal to the instrument at or less than 1,000 volts above ground,
no protective case is required. However, it is good practice to
protect voltmeters subject to more than 5,000 volts with suitable
over-voltage protection device(s) across the instrument terminal in
case the winding opens.
3) Transmission line meters and any other radio-frequency
instrument which is necessary for the operator to read, shall be so
installed as to be easily and accurately read without the operator
risk contact with circuits carrying high potential radio-frequency
energy.
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e. Indicating Instruments
1) Each FM broadcast station should be equipped with
indicating instrument for measuring the plate voltage and current of
the last radio stage and the transmitting line radio frequency power.
2) In the event that the plate voltage or plate ampere in the
last radio stage is defective, the operating power shall be
maintained by means of the radio-frequency power meter.
f. Installation
1) The installation shall be made in suitable quarters.
2) Since an operator must be on duty at the transmitter
control during operation, suitable facilities for his welfare and
comfort shall be provided at the control point.
g. Other technical data. An accurate circuit diagram, as furnished
by the manufacturer of the equipment, shall be retained at the
transmitter location.
5.2.4 Monitoring Equipment
a. Frequency Monitor
1) The licenses of each station have in operation, either at the transmitter
or at the place where the transmitter is controlled, a frequency monitored of a
type approved by the Commission which shall be independent of the frequency
control of the transmitter.
2) In the event that the frequency monitor becomes defective, the station
may be operated without such equipment pendings its repair or replacement for a
period not in excess of 60 days without further authority of the Commission:
Provided, That:
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a) Appropriate entries shall be made in the operation log of the station
to show the date and the time the monitor was removed from and restored
to service.
b) The Engineer in Charge of the Region in which the station is located
shall be notified both immediately after the monitor is found to be defective
and immediately after the repaired or replacement monitor has been
installed and is functioning properly.
c) The frequency of the station shall be compared with an external
frequency source of known accuracy at sufficiently frequent interval to
insure that the frequency is maintained with the tolerance. An entry shall
be made in the station log as to the method used and the result thereof.
3) If conditions beyond the control of the licensee or permittee prevent the
restoration of the monitor to service within the above allowed period, informal
request may be filed with the Engineer in Charge of the Region in which the
station is located for such additional time as may be required to complete rep[airs
of the defective instrument or equipment.
Modulation Monitor
The modulation monitor (deviation monitor) is an optional requirement for an
FM station. The FM station may refer to the monitoring section of the Authority, to
the Standard Authority of the KBP of to other FM station for modulation
measurements.
5.3 Stereophonic Transmission Standards
a. The modulating signal for the main channel shall consist of the sum of the
left and right signals.
b. A pilot subcarrier at 19,000 Hertz plus or minus 2 Hz, shall be transmitted
that frequency-modulate the main carrier between the limits of 8 to 10 percent.
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c. The stereophonic subcarrier shall be the second harmonic of the pilot
subcarrier and shall cross the time axis with a positive slope simultaneously with
each crossing of time axis by the pilot subcarrier.
d. Amplitude modulation of the stereophonic subcarrier shall be used.
e. The stereophonic subcarrier shall be suppressed to a level less than one
percent modulation of the main carrier.
f. The stereophonic subcarrier shall be capable of accepting audio frequency
from 50 to 15,000 Hz.
g. The modulation signal for the stereophonic subcarrier shall be equal to the
difference of the left and right signals.
h. The pre-emphasis characteristics of the stereophonic subchannel shall be
identical with those of the main channel with respect to phase and amplitude at
all frequencies.
i. The sum of the side bands resulting from amplitude modulation of the
stereophonic subcarrier shall not cause a peak deviation of the main carrier in
excess of 45 percent of total modulation (excluding SCA subcarriers) when only
a left (or right) signal exists; simultaneously in the main channel, the deviation
when only a left (or right) signal exists shall not exceed 45 percent of total
modulation (excluding SCA subcarriers).
j. The maximum modulation of the main carrier by all SCA subcarrier be
limited to 10 percent.
k. At the instant when only a positive left signals applied, the main channel
modulation shall cause an upward deviation of the main carrier frequency; and
the stereophonic subcarrier and its sidebands signal shall cross the time axis
simultaneously and in the same direction.
l. The ratio of peak main channel deviation to peak stereophonic
subchannel deviation, when only a steady state left (or right) signal exists, shall
be within plus or minus 3.5 percent of unity for all levels of this signal and all
frequency from 50 to 15,000 Hertz.
m. The phase difference between the zero points of the main channel signal
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and the stereophonic subcarrier sidebands envelope, when only steady state left
(or right) signal exists, shall exceed plus or minus 3 degrees for audio modulating
frequencies from 50 to 15,000 Hz.
Note: If the stereophonic separation between left and right stereophonic
channel is better than 29.7 decibels and audio modulating frequencies between
50 to 15,000 Hz it will be assumed that (l) and (m) of this section have been
complied with.
n. Cross-talk into the main channel caused by a signal in the main
stereophonic subchannel shall be attenuated at least 40 decibels below 90
percent modulation.
o. Cross-talk into the stereophonic subchannel caused by a signal in the
main channel shall be attenuated at least 40 decibels below 90 percent
modulation.
p. For required transmitter performance the maximum modulation to be
employed is 90 percent (excluding pilot subcarrier) rather than 100 percent.
q. For electrical performance standard of the transmitter and associated
equipment, 100 percent modulation is referred to include the pilot subcarrier.
5.4 Subsidiary Communications Authorization (SCA)
5.4.1 Permissible uses of the SCA must fall within one or both of the following
Categories
a. Transmission of programs which are of a broadcast nature, but which are of
interest primarily to limited segments of the public wishing to subscribe thereto.
Illustrative services include: background music stereocasting, detailed weather
forecasting, special time signal; and other material of broadcast nature expressly
designed and intended for business, professional, educational, religious, trade,
labor, agriculture, or other groups engaged in any lawful activity.
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b. Transmission of signals which are directly related to the operation of FM
broadcast station; for example: relaying of broadcast material to other FM and
standard AM broadcast stations; remote cueing and other circuits; remote control
telemetering functions associated with authorized STL operation, and similar
uses.
5.4.2 An application for SCA shall specify the particular nature and purpose of
the proposed use. If visual transmission of program material is contemplated, the
application shall include certain technical information concerning the visuals
system, on which the Authority shall rely in issuing an SCA. If any significant
change is subsequently made in the system, revised information shall be
submitted. The technical information to be submitted is as follows:
a. A full description of the visual transmission system.
b. A block diagram of the system, as installed in the station, with all
components including filters, identified as to make and type. Response curves of
all composite filters shall be furnished.
5.4.3 SCA operations may be conducted without restriction as to time, so long as
the main channel is programmed simultaneously.
5.4.4 Nature of the SCA
a. The SCA is of a subsidiary or secondary nature shall not exist apart from
FM license or permit. No transfer or assignment of it shall be made separate from
the FM broadcast license and failure to transfer the SCA with the FM license
renders the SCA void. Any assignment or transfer of an SCA shall, if desired,be
requested as part of the main stations transfer or assignment application.
The licensee or permit must seek renewal of FM license or permit; failure
to renew the latter automatically terminates the SCA.
b. The grant or renewal of an FM license or permit shall not be furthered or
promoted by the proposed or past operation under an SCA; the license must
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establish that this broadcast operation is in the public interest wholly apart from
the SCA activities.
5.4.5 Multiplex Operations Engineering Standards
a. Frequency modulation of SCA subcarriers shall be used.
b. The instantaneous frequency of SCA subcarriers shall at all times be within
the range 20 to 75 kHz; Provided, however, that when the station is engaged in
stereophonic broadcasting, the instantaneous frequency of SCA subcarrier shall
at all times be within the range 53 to75 kHz.
c. The arithmetic sum of the modulation of the main carrier by SCA
subcarriers shall not exceed 30 percent: Provided, however, that when the
station is engaged in stereophonic broadcasting, the arithmetic sum of the main
carrier by the SCA subcarrier shall not exceed 10 percent.
d. The total modulation of the main carrier, including SCA subcarriers, shall
meet the requirements of 6.2.2.
e. Frequency modulation of the main carrier caused by the SCA subcarrier
operation shall, in the frequency range 90 to 15,000 Hz, be at least 60 dB below
100 percent modulation: Provided, however, that when thestation is engaged in
stereophonic broadcasting, frequency modulation of the main carrier by the SCA
subcarrier operation shall, in the frequency range 50 to 53,000 Hz, be at least 60
dB below 100 percent modulation.
f. The center frequency of each SCA subcarrier shall be kept at all times
within 500 hertz of the authorized frequency.
5.4.6 Facsimile engineering standards
The following standards apply to facsimile broadcasting under SCA
operations.
a. Rectilinear scanning shall be employed, with scanning spot progressing
from left to right and scanned lines progressing from top to bottom of the subject
copy.
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b. The standard index of cooperation shall be 984.
c. The number of scanning lines per minute shall be 360.
d. The line-use ratio shall be 7/8, or 315 degrees of the full scanning cycle.
e. The 1/8 cycle or 45 degrees not included in the available scanning line shall
be divided into 3 equal parts, the first 15 degrees being used for transmission at
approximately white level, the second 15 degrees for transmission at
approximately black level, and the third 15 degrees for transmission at
approximately white level.
f. An interval of not more than12 seconds shall be available between two
pages of subject copy, for the transmission of a page-separation signal and/or
other services.
g. Amplitude or (frequency-shift) modulation of the subcarrier shall be used.
h. Subcarrier modulation shall normally vary approximately linearly with the
optical density of the subject copy.
i. Negative modulation shall be used, i.e., for amplitude modulation of
subcarrier, maximum subcarrier amplitude and maximum radio frequency swing
on black; for frequency modulation of subcarrier, highest instantaneous
frequency of subcarrier on black.
j. Subcarrier noise level shall be maintained at least 30 dB below maximum
(black) picture modulation level, at the radio transmitter input.
k. The facsimile subcarrier transmission shall be conducted in the frequency
range between 22 and 28 kHz. Should amplitude modulation of the carrier be
employed the subcarrrier frequency shall be 25 kHz with sidebands extending
not more than 3 kHz in either direction from the subcarrier frequency. Should
frequency modulation of the subcarrier be employed the total swing at the
subcarrier shall be within the range from 22 to 28 kHz, with 22 kHz
corresponding to white and 20 kHz corresponding to black on the transmitted
copy. In multiplex operation, the modulation of the FM carrier by the modulated
subcarrier shall not exceed 5 percent. In simplex operation , the modulation of
the FM carrier by the modulated subcarrier shall not exceed 30 percent.
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i. During periods of multiplex facsimile transmission, frequency modulation of
the FM carrier cause by the aural signals shall, in the frequency range from 20 to
30 kHz, be at least 60 db below 100 percent modulation. Frequency modulation
of the FM carrier caused by the facsimile shall, in the frequency range from 50 to
15,000 Hertz, be at least 60 dB below 100 percent modulation.
5.5 Studio, Equipment and Allied facilities
5.5.1 The studio being the recognized source of program materials and
other forms of intelligence of various kinds and content, must be properly
equipped to faithfully respond to these impressions and produce the same to the
highest degree possible, up to the turnover point which is the transmitter input.
5.5.2 Studio location and Layout
a. Each shall be associated with a control room for which the
operational area of the studio may viewed with. However, when the studio
and the control rooms are integrated into one, an announcer shall perform
simple panel type functions like level adjustments and switching during
his/her board hours.
b. Studios and control rooms shall be constructed that they are
adequately insulated from source of extraneous noise and vibration, and
the acoustic treatment of such studio and control rooms shall be in
accordance with good engineering practice.
5.6 Emergency Equipment & Facilities
5.6.1 Alternate Main Transmitter
a. The regular and the optional main transmitter shall be located in
a single place.
b. The external effects from both regular and main transmitters
shall substaintially be the same as to frequency and stability.
5.6.2 Auxiliary Transmitter
a. An auxiliary transmitter shall be provided and may be installed in
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the location as the regular main transmitter or in another location.
b. Its operation power shall not be less than 10 % or never greater
than the authorized operating power of the main transmitter.
c. A licensed operator shall be on control whenever an auxiliary
transmitter is placed in operation.
d. When installed in a location different from that of the regular
transmitter, a type-approved modulation monitor and frequency monitor
are required to be installed with it.
5.7 Spare Component Parts
In order to cut down-times during scheduled on-air operations, a
reasonable variety and number of spare components appropriate to the
equipment installed at the site, shall be kept on hand.
6. Broadcast Auxiliary Services
6.1 Broadcast auxiliary services fall under these three categories:
a. Studio-to-Transmitter Links (STL)
b. Remote Pick-up Broadcast Station
c. Communication, Coordination, and Control Link.
6.2 The frequency bands and the transmitter power output authorized for the
above services are as follows:
a. Studio-to-Transmitter Link
BAND A 300-315 MHz
BAND B 734-752 MHz
BAND C 942-952 MHz
The maximum power allowance for STL BANDS A, B, and C shall be
15 watts.
b. Remote Pick-up Broadcast Station
BAND A 315-325 MHz
BAND B 450-451 MHz
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BAND C 455-456 MHz
The maximum power allowable for remote Pick-up BANDS A, B, and C
shall be 35 watts.
c. Communication, Coordination, and Control Link
BAND A 4-12 MHz (non-exclusive)
BAND B 25.67-26.1 MHz
BAND C 162.235-162.615 MHz
166.250 and 170.150 MHz
BAND D 432.5-433 MHz
437.5-438 MHz
The maximum power allowable for Communication, Cooperation, and
Control Link shall be:
BAND A - 100 watts (SBS)
BAND B - 160 watts (ERP)
BAND C - 160 watts (ERP)
BAND D - 200 watts (for repeater)
6.3 The National Telecommunication Commission shall authorized the
employment of any one or all this broadcast transmission services to a station
depending on the necessity and availability of frequencies for the purpose. Any
AM or FM station authorized to operate is entitled to used any broadcast
transmission services relevant to the efficient operation of the station where the
use of physical lines or cables are not feasible.
7. OPERATING REQUIREMENTS
7.1 Hours of Operation
7.1.1 Minimum Operating Schedule - The license of each FM station shall
be maintain a minimum operating schedule of two-thirds of the total hours
that is authorized to operate, except in emergencies when, due to causes
beyond the control of the licensee, it becomes impossible to continue
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operating. The station may cease operation for a period not exceeding 10
days.
7.1.2 Broadcast outside the authorized regular operating schedule (as
before regular sign-on schedules and/or beyond the regular sign-off
schedules may be aired without prior authorization from the appropriate
regulatory body provided the program falls under emergency category or
of very important relevance to the station existence. The information shall
be entered in the program and operating logs at the time the broadcast
was aired.
7.1.3 If a permanent discontinuance of operation is being contemplated,
then the licensee shall not notify the appropriate regulatory body in writing,
at least two (2) days before the actual discontinuance is affected.
7.2 Other operating Requirements
7.2.1 The center frequency of each FM broadcast station shall be
maintained within 2000 Hertz of the assigned center frequency.
7.2.2 The percentage of modulation shall be maintained as high as
possible consistent with good quality transmission and good broadcast
practice and in no case less than 85 percent nor more than 100
percent on peaks of frequent recurrence during any selection which is
normally transmitted at the highest level of the program under
consideration.
7.2.3 The operating power of each station shall be maintained as near as
practicable to the authorized operating power, and shall not be exceed the
limits of 5 percent above and 10 percent below the authorized power,
except that in an emergency when it becomes impossible to operate within
the authorized power, the station may be operated with reduced power.
The operating power of each station shall be determined by indirect
method. This the product of the plate voltage (Ep) and the plate current
(Ip) of the last radio stage, and an efficiency factor, F; that is, Operating
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Power
= Ep x Ip x F.
The efficiency factor, F, shall be established by the transmitter
manufacturer for each type of transmitter.
7.2.4 The station equipment shall be so operated, tuned and adjusted
that emission outside of the authorized channel do not cause harmful
interference to the reception of the other stations. FM broadcast station
shall maintain the bandwidth occupied by their emissions in accordance
with the specification set forth in this section. Station shall achieve the
highest degree of compliance practicable with their existing equipment.
In either case, should harmful interference to the reception of other
radio stations occur, the licensee may be required to take such further
steps as may be necessary to eliminate the interference.
7.3.5 If a limiting or compensating amplifier is employed, care should be
maintained in its use due to pre-emphasis in the transmitting system.
7.3 Posting of Station and Operator Licenses
7.3.1 The station license and other instrument (s) of station authorization
shall be posted in a conspicuous place and in such a manner that all
terms are visible, at the place the licensee considers to be principal control
point of the transmitter. At all other control point listed on the station
authorization, a photocopy of the station license and other instrument(s) of
station authorization shall be posted.
7.4 Operators Requirements
7.4.1 Radio operators holding a valid radiotelephone first class operators
license, except as provided for in paragraph 7.4.2 of this section, shall be
in actual charge of the transmitting apparatus and shall be on duty either
at the transmitter location or remote control point.
7.4.2 A station which is authorized with a power of 10 kilowatts or less
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may be operated by person holding commercial radio operators
license of any class except those with an aircraft radiotelephone
operator authorization or a temporary limited radiotelephone operator
class license, when the equipment is so designed that the stability of the
frequency is maintain by the transmitter itself within the limits of tolerance
specified, and none of the operation, except those specified in sub-
paragraphs (a) through (d) of this paragraph, necessary to be performed
during the course of normal operation, may cause off-frequency operation
or result in any unauthorized radiation. Adjustments of the transmitting
equipment by such operators, except when under the immediate
supervision of a radio-telephone first class operator, shall be limited to the
following:
a. Those necessary to commerce or terminate transmitter emission
as a routine matter.
b. Those external adjustments that may be required as a result of
variations of primary power supply.
c. Those external adjustments which may be necessary to insure
modulation within the limit required.
d. Those adjustment necessary to effect any change in operating
power which may be required by the stations instrument(s) of
authorization. Should the transmitting apparatus be observed to the
operating in a manner inconsistent with the station instrument of
authorization and none of the above are effective in bringing it to the
proper operation, a person holding other than ratio telephone first class
operators license and not acting under the immediate supervision of a
radio-telephone first class operators, shall be required to terminate the
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stations emissions.
7.4.3 A station shall employ at least one full-time first class radio-
telephone operators whose primary duty shall be to effect and ensure the
proper functioning and transmitting equipment.
7.5 Log Requirement
The licensee or permittee of each FM broadcast station shall maintain
separate program and operating logs and shall require entriesto be made as
follows:
7.5.1 In the program log
a. An entry of the time each station identification announcement
(call letters, frequency and location) is made.
b. An entry briefly describing each program broadcast such as
music, drama, speech, etc. together with the name at the beginning
and opening of the complete program. If the mechanical record is used,
the entry shall show the exact nature thereof , such as record,
transcription etc. and the time is it announced as a mechanical record. If
a speech is made by the political candidate, the name and political
affiliation of such a speakers shall be entered.
c. An entry showing that each sponsored program broadcast has
been announced as sponsored, paid for, or furnished by the sponsored.
d. An entry showing, each program of network origin, the name of
the network originating the program.
7.5.2 In the operating log
a. An entry of the time the station begins to supply power to the
antenna and the time it stops.
b. An entry of the time the programs begins and ends.
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c. An entry of each interruption to the carrier wave, its cause, and
duration; or an interruption of program transmission.
d. An entry of the following every 30 minutes:
1) Operating constants of the last radio frequency stage ( total plate
current and plate voltage)
2) Any other entry required by the Instrument of Authorization.
7.5.3 If a maintenance log is keep aside from the operating log, the
following entries are recommended:
a. An entry of the time and result of the test of auxillary transmitter.
b. A notation of all frequency checks and measurements made
Independently of the frequency monitor and of the correlation of
these measurements with frequency monitor Indications.
c. A notation of the calibration check of automation recording
devices. An entry of the data and time of removal to the restoration
to service of any of the following equipment in the event it becomes
defective:
1) Final R.F. stage plate volt meter readings.
2) Final R.F. stage plate volt-meter readings.
3) Transmission line radio frequency voltage current, or
power meter readings.
4) The entries required concerning quarterly inspection of
the condition of the tower lights and associated control equipment
and an entry when towers are cleaned and/ or repainted.
5) Entries which described fully any experimental operation
of transmitter.
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6) Any other entries required by the current Instrument of
Authorization of the station and the provision of this subpart.
7.5.4 A log must kept of all operations during the experimental period. If t
he entries required above are not application thereto then the
entries shall be made so as to fully describe the operation.
7.5.5 Logs of FM broadcast stations shall be retained by the licensee or
permittee for a period of two (2) years: Provided, however, that logs
involving communications incident to a disaster or which include
communications incident to or involved in an Investigation by the
appropriate regulatory body and concerning which licensee or permittee
has been notified, shall be retained by the licensee or permittee until he is
specifically authorized in writing by the appropriate regulatory body to
destroy the: Provided further, that logs incident to or involved in any claim
or complaints of the licensee or permittee has notice, shall be retained by
the licensee or permittee until such claim and complaint has been fully
satisfied or until the same has been barred by the statue limiting the time
for the filling of suits upon such claims.
7.5.6 Each log shall be kept by the person or persons competent to do so,
having actual knowledge of the fact required, who shall sign to log when
starting duty and again when going off duty. The log shall be made
available upon request by an authorized representative(s) of the
appropriate regulatory body during the reasona
