BROADCASTING
Engr. Raymond J. Pidor, PECE
BROADCASTING
 It
refers to the airborne transmission
of electromagnetic audio signals
(radio) or audio-visual signals
(television) that are readily
accessible to a wide population via
standard receivers.
AM BROADCAST STANDARDS
Parameters
Philippine
Standards
International
Standards
Freq. Band
535-1605 kHz
535-1605 kHz
No. of Channels
118
107
BW per Channel
9kHz
10kHz
Permitted BW
30kHz
30kHz
Channel Spacing
36kHz (4 channels
apart)
30kHz (3 channels
apart)
Center Freq Stability
± 20Hz
± 20Hz
Baseband Freq
50-15000kHz
50-15000kHz
Type of Modulation
AM
AM
Type of Emission
A3E
A3E
Guardband
36kHz
30kHz
Antenna Polarization
Vertical
Vertical
Type of Receiver
Superheterodyne
Superheterodyne
Intermediate Freq
455kHz
455kHz
MAXIMUM POWER ALLOCATION IN KW
Area
Low Band
(529-918kHz)
Mid Band
(919-1312 kHz)
High Band
(1313-1705kHz)
Metro Manila
10
20
30
Metro Cebu
10
20
30
Other Areas
5
10
15
AM ANTENNA SYSTEM
 Antenna
Site Considerations
Location in relation to the population to
be served and to other installations and
airports.
 Conductivity of the soil at and
immediately adjacent to the site.
 Conductivity of the path between the
site and the target area.

AM ANTENNA SYSTEM
 Antenna
Design Considerations
The transmitting antenna system shall
be vertically polarized and shall radiate
an effective field of not less than that of
a 60-degree vertical radiator.
 The antenna, antenna lead-in, and
counterpoise shall be installed so as not
to present hazard.

AM TRANSMITTER
 Transmitter
Location and Layout
Considerations
Adequate space
 Adequate ventilation and
airconditioning
 Adequate lighting

AM TRANSMITTER

Transmitter Design
Parameters
Phil. Standards
Carrier Power Limits
10% of Full Power
Max. Modulation for Satisfactory
Operation
85%
Operating Frequency Limits
± 10Hz of Assigned Freq.
Carrier Shift
5%
Carrier Hum and Extraneous
Noise Level
45dB below 400Hz tone
Total Audio Frequency Distortion
<5% Harmonics @ 0-84% mod
<7.5% Harmonics @ 85-95% mod
AM TRANSMITTER
 Alternate
Main Transmitter
Consideration
The regular and alternate main
transmitter to be co-located in a single
place.
 Both transmitters shall maintain the
same parameters especially with
regards to authorized operating power,
frequency stability, and etc.

AM TRANSMITTER
 Auxiliary
Transmitter Consideration
May be installed either in the same
location as the regular main
transmitter or in another location.
 Its operating power may be less but
never greater than the authorized
power of the regular main transmitter.

AM BROADCAST OPERATING
REQUIREMENTS
 Operating
Schedule
2/3 of the total hours that it is
authorized to operate between 6AM to
6PM local standard time.
 2/3 of the total hours that it is
authorized to operate between 6PM to
midnight local standard time.

AM BROADCAST OPERATING
REQUIREMENTS
 Program
Log Entries
An entry of the time each station identification
announcement is made.
 An entry briefly describing each program
broadcast.
 An entry showing that each sponsored
program broadcast has been announced as
sponsored.
 An entry showing, for each program of
network origin, the name of the network
originating the program.

AM BROADCAST OPERATING
REQUIREMENTS
 Operating
Log Entries
An entry of the time the station begins t
supply power to the antenna an the
time it stops.
 An entry of the time the program begins
and ends.
 An entry of each interruptions.
 An entry of the following every 30
minutes: Operating constants and
antenna current.

AM BROADCAST TERMINOLOGIES
 Authorized

The carrier frequency authorized by the
National Telecommunications Commission
(NTC).
 Carrier

wave
A sinusoidal voltage or current generated in a
transmitter and subsequently modulated by a
modulating wave.
 Carrier

frequency
frequency
The frequency of the carrier wave.
AM BROADCAST TERMINOLOGIES
 Daytime

Refers to that period of time between 2100
GMT – 1000 GMT (5:00AM – 6:00PM local
standard time).
 Experimental

Refers to that period of time between 1600
GMT -2100 GMT (12 midnight -5:00 AM local
standard time).
 Intermittent

period
service area
The area receiving service from the ground
wave but beyond the primary service area and
subject to some interference and fading.
AM BROADCAST TERMINOLOGIES
 Maximum

The greatest percentage of modulation that may
be obtained by a transmitter without producing
in its output harmonics of the modulating
frequency in excess of those permitted by these
regulations.
 Maximum

percentage of modulation
rated carrier power
The maximum power at which the transmitter
can be operated satisfactorily and is determined
by the design of the transmitter.
 Nighttime

Refers to that period of time between 1000-2100
GMT (6:00PM – 5:00AM local standard time).
AM BROADCAST TERMINOLOGIES
 Operating

power
The power that is actually supplied to the radio
station.
 Percentage

The ratio of half the difference between the
maximum and minimum amplitudes of the
amplitude wave to the average amplitude
expressed in percentage.
 Primary

modulation (AM)
service area
The area in which the ground wave field of
3.16mV/m (70dBu) is not subject to objectionable
interference or objectionable fading.
AM BROADCAST TERMINOLOGIES
 Secondary

The area served by the skywave and not
subject to objectionable interference. The
signal is subject to intermittent variations in
intensity.
 Secondary

service area
station
A station operating on any one channel and is
designed to render service over a primary
service area which is limited by the subject to
such interference as may be received from a
clear-channel station.
AM BROADCAST TERMINOLOGIES
 Spurious

The emission of any frequency outside of the
assigned channel or authorized band of
frequency and tolerances allowed by these
regulations.
 Total

emission
harmonic distortion (THD)
The effective value of the harmonic voltages
present in the audio frequency output of the
equipment under test.
FM BROADCASTING STANDARDS
Parameters
Philippine Standards
Freq. Band
88-108 MHz
No. of Channels
25
BW per Channel
200 kHz
Permitted BW
240 kHz (monophone)
Channel Spacing
800 kHz
Center Freq Stability
± 2 kHz
Baseband Freq
50-15000 Hz
Type of Modulation
FM
Type of Emission
F3E
Guardband
25 kHz above USB and
below LSB
Antenna Polarization
Horizontal or circular
Type of Receiver
Superheterodyne
Intermediate Freq
10.7 MHz
Freq Deviation
± 75 kHz (for 100% mod)
Pre-Emphasis
75µs time constant
Pilot Subcarrier
19 kHz
CLASSES OF STATIONS
Station
Authorized Power
Class A
Not xceeding 15 kW
Class B
Not xceeding 10 kW
Class C
Not xceeding 1 kW
Class D
Not xceeding 10 W
FM FREQUENCY ALLOCATION
𝐹𝑀𝑛 = 𝐹𝑀1 + 𝑛 − 1 𝐵𝑊
(𝑀𝐻𝑧)
Where:
FM = Channel Freq in MHz
FM1 = Freq of the 1st FM Channel (88.1 MHz)
n = Channel Number
BW = Channel Bandwidth (200 kHz)
Channel No.
FREQ ASSIGNMENTS
Freq. (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
FM70
101.9
FM74
102.7
FM78
103.5
FM82
104.3
FM86
105.1
FM90
105.9
FM94
106.7
FM98
107.5
RADIO-FREQ PROTECTION RATIO (IN DECIBEL)
Freq
Spacing
(kHz)
Monophonic
Stereophonic
Steady
Interference
Tropospheric
Interference
Steady
Interference
Tropospheric
Interference
0
36
28
45
37
25
31
27
51
43
50
24
22
51
43
75
16
16
45
37
100
12
12
33
25
150
8
8
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
FM TRANSMITTER CONSIDERATIONS
 Construction

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 Philippine Electrical Code.
FM TRANSMITTER CONSIDERATIONS
 Enclosure

The transmitter shall be enclosed in a
metal frame or grille separated from the
operating space by a barrier or other
equivalent means.
FM TRANSMITTER CONSIDERATIONS
 Grounding
of Controls
All external metallic handles and
controls accessible to the operating
personnel shall be effectively grounded.
 No circuit in excess of 150V shall have
any part exposed to direct contact.

FM TRANSMITTER CONSIDERATIONS
 Interlocks

All access doors shall be provided with
interlocks which will disconnect all
voltages in excess of 350V when any
access door is opened.
FM TRANSMITTER CONSIDERATIONS
 Bleeder

Resistors
Proper bleeder resistors 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 350V
within 2 seconds after the access door is
opened.
FM TRANSMITTER CONSIDERATIONS
 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.
 All instruments having more than
1000V potential to ground shall be
protected by a cage or cover.

FM STEREO BROADCASTING
Two audio channels (L & 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 is modulated directly in the
Baseband assignment between 50 and 15kHz.
 The difference signal is DSBSC modulated in the
23 to 53kHz slot about a stereophonic Subcarrier
of 38kHz.

FM STEREO BROADCASTING
FM STEREO BROADCASTING
Parameters
Philippine Standards
Pilot Subcarrier
19 kHz ± 2 Hz
Stereophonic Subcarrier
38 kHz (2nd harmonic of Pilot
Subcarrier)
Stereophonic Subcarrier
suppression level
<1% modulation of the main
carrier
BROADCAST TRANSMISSION SERVICES

Studio-to-Transmitter Link (STL)


Remote Pickup Broadcast Stations


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.
Stations in this service are to be used for the
transmission of aural programming materials and
associated cues and data.
Communications, coordination, and control links
FM BROADCAST TERMINOLOGY
 Antenna

It is the height of the radiation center of the
antenna above the terrain 3 to 16 km from the
antenna.
 Antenna

Height Above Terrain (HAAT)
field gain
It is the ratio of the effective free space field
intensity produced at 1.6 km in the horizontal
plane expressed in mV/m for 1 kW antenna
input power to 137.6 mV/m.
FM BROADCAST TERMINOLOGY
 Antenna

It means the square of the ratio of the rms free
space field strength produced at 1.6 km in the
horizontal plane, in mV/m.
 Center

power gain
frequency
It is the average frequency of the emitted wave
when modulated by a sinusoidal signal.
FM BROADCAST TERMINOLOGY
 Crosstalk

An undesired signal occurring in one channel
caused by an electrical signal in another
channel.
 Effective

Radiated Power
It is the product of the transmitter power and
the antenna power gain of the antenna field
gain squared.
FM BROADCAST TERMINOLOGY
 Field

It is the electric field intensity in the
horizontal direction.
 FM

Intensity
stereophonic broadcast
The transmission of a stereophonic program by
a single FM broadcast station utilizing the
main channel and stereophonic subchannel.
FM BROADCAST TERMINOLOGY
 Free

space field intensity
It is the field intensity that would exist a
point, in the absence of waves reflected from
the earth or other reflecting objects.
 Frequency

swing
It means the instantaneous departure of the
frequency of the emitted wave from the center
frequency resulting from modulation.
FM BROADCAST TERMINOLOGY
 Main

channel
The band of frequencies from 50-15kHz which
frequency modulate the main carrier.
 Multiplex

transmission
It means the simultaneous transmission of two
or more signals within a single channel.
FM BROADCAST TERMINOLOGY
 Pilot

subcarrier
It serves as a control signal for use in
reception of FM stereophonic broadcast.
 Service

area
It refers to the area bounded by a field
intensity that is equal or greater than the
minimum value necessary to permit a desired
reception quality in the presence of noise and
interference, and from which the RF
Protection Ratio is extended
FM BROADCAST TERMINOLOGY

Stereophonic separation


It is 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.
Stereophonic subcarrier