KBP StandardsFM Broadcasting

Paul BuenvenidaJerome Cansado

Ian HatolSean Natividad

1. Introduction

• Cause:– Importance of FM broadcasting in the Philippines increased

• Derived from:– CCIR recommendations– Engineering data– Rules and regulations of Federal Communications Commission– Data supplied by manufacturers of radio equipment and

licensees of FM broadcast stations

• To be improvised to be effective and compatible with technical progress

2. Definition of Terms• 2.1 FM broadcast band

– Portion of the radio frequency spectrum from 88 MHz to 108 MHz. the band is divided into 100 channels.

• 2.2 FM broadcast channel– A band of frequencies 200 kHz wide and is designated by its center

frequency. Channels for FM broadcast stations begin at 88.1 MHz and continue in successive steps of 200 kHz to and including 107.9 MHz.

• 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– 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 modulation signal.

FM Broadcast Station

2. Definition of Terms• 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– The height of the radiation center of the antenna above the terrain

3 km to 16 km from the antenna.

• 2.8 Antenna field gain– The ratio of the effective free space field intensity produced at 1.6

km in the horizontal plane expressed in millivolts per meter for 1 kW antenna input power, to 137.6 millivolts per meter.

Antenna HAAT

2. Definition of Terms• 2.9 Antenna power gain

– Square of the ratio of the rms free space field strength produced at 1.6 km in the horizontal plane, in millivolts per meter for 1 kW antenna power, to 137.6 millivolts per meter. This ratio should be expressed in decibels (dB).

• 2.10 Effective radiated power (ERP)– Product of the transmitter power multiplied by

a. Antenna power gainb. Antenna field gain squared

• 2.11 Field Intensity– “Field intensity” as used in these standards shall mean the

electric field in the horizontal direction.

2. Definition of Terms• 2.12 Free space field intensity

– Field intensity that would exist at a point, in the absence of reflective waves.

• 2.13 Service area– Service resulting from an assigned ERP and antenna HAAT.

• 2.14 Radio-frequency (R.F.) Protection Ratio– Value of the radio-frequency wanted-to-interfering signal ration

that enables the radio-frequency protection ratio to be obtained at the output of a receiver.

• 2.15 Percentage modulation– Ratio of the actual frequency swing to the frequency swing defined

as 100 percent modulation (± 75 kHz), expressed in percentage.

2. Definition of Terms• 2.16 Multiplexing

– Two or more independent sources of information combined for carriage over a single medium (carrier frequency) and separated at the receiving ends.

• 2.17 FM Stereophonic Broadcast– 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.

• 2.19 Composite Baseband Signal– Signal which is the sum of all signals which frequency-modulates the main

carrier.– Signal components: main channel signal, modulated stereophonic subcarrier,

pilot subcarrier and SCA subcarrier(s).

2. Definition of Terms

• 2.20 FM Baseband– Frequency band from 0 Hz to a specified upper frequency

which contains the composite baseband signal.

• 2.21 Main Channel– Band of frequencies from 50 Hz (or less) to 15 kHz on the

FM baseband which contains the main channel signal

• 2.22 Main Channel Signal– Combination of the monophonic or left and right audio

signals which frequency-modulates the main carrier.

2. Definition of Terms• 2.23 Stereophonic Sound

– Audio information carried by plurality of channels arranged to afford the listener a sense of the spatial distribution of sound sources.

• 2.24 Stereophonic Sound Subcarrier– Subcarrier within the FM broadcast baseband used for stereophonic

sound reception of the main broadcast program service.

• 2.25 Stereophonic Sound Subchannel– The band of frequencies from 23 kHz to 99 kHz containing sound

subcarriers and their associated sidebands.

• 2.26 Subchannel– Transmission path specified by a subchannel signal occupying a specified

band of frequencies.

2. Definition of Terms• 2.28 Pilot sub-carrier

– Serves as a control signal for use in the reception of FM stereophonic broadcast.

• 2.29 Left (or Right) Signal– Electrical output of a mic or combination of mics placed to convey

intensity, time, and location of the source of sound.

• 2.30 Left (or Right) stereophonic channel– Left (or Right) signal as electrically reproduced in the reception of an FM

stereophonic broadcast.

• 2.31 Stereophonic Separation– Ratio of electrical signal caused in the right (or left) stereophonic channel

and left (or right) stereophonic channel by the transmission of only a right (or left) channel.

2. FM Baseband

2. Definition of Terms• 2.32 Frequency Deviation

– Peak difference between the instantaneous frequency of the modulated wave and the carrier frequency.

• 2.33 Injection Ratio– Ratio of the frequency swing of the carrier by a subchannel signal to

the frequency swing defined as 100 % modulation. The total injection is the arithmetic sum of each subchannel.

• 2.34 Cross-talk– Undesired signal occuring in one channel caused by and electrical

signal in another channel.

• 2.35 Linear Crosstalk (System Crosstalk)– Created by phase or gain inequalities in another channel(s).

2. Definition of Terms

• 2.36 Nonlinear Crosstalk (Transmitter Crosstalk)– Created by harmonic distortion or intermodulation of electrical

signal(s) in another channel(s).

• 2.37 SCA– Subsidiary Communications Authorization.

• 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.

• 2.39 Line-use ratio– As applied to facsimile broadcasting, is the ratio of the available line to

the total length of scanning line.

Radiofax

2. Definition of Terms

• 2.40 Available Line– Portion of the total length of scanning line that can

be used specifically for picture signals.

• 2.41 Rectilinear scanning– 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 transmitted or reflected light.

2. Definition of Terms• 2.43 Experimental Period

– Period between 12 midnight to 5:00 a.m. local standard time (1600-2100 GMT).

– 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, provided no interference is caused to other stations maintaining a regular operation schedule within such period.

• 2.44 Operating Power– Product of the plate voltage (Ep) and the plate current (Ip) of the last

radio stage and efficiency factor, F, expressed: .– Indirect method of determining operating power of each FM station for

the purpose of specifying the operating power range of FM transmitters.– Efficiency factor (F) shall be established by the transmitter manufacturer.

2. Definition of Terms

• 2.45 Last radio stage– Oscillator or radio-frequency- power amplifier

stage which supplies 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 Operator’s License of its equivalent except those mentioned in Section 7.4 as issued by the existing regulatory body.

3. Allocation of Frequencies for FM Broadcast StationsChannel No.

Frequency (MHZ)

Channel No.Frequency

(MHZ)201 88.1 226 93.1202 88.3 227 93.3203 88.5 228 93.5204 88.7 229 93.7205 88.9 230 93.9206 89.1 231 94.1207 89.3 232 94.3208 89.5 233 94.5209 89.7 234 94.7210 89.9 235 94.9211 90.1 236 95.1212 90.3 237 95.3213 90.5 238 95.5214 90.7 239 95.7215 90.9 240 95.9216 91.1 241 96.1217 91.3 242 96.3218 91.5 243 96.5219 91.7 244 96.7220 91.9 245 96.9221 92.1 246 97.1222 92.3 247 97.3223 92.5 248 97.5224 92.7 249 97.7225 92.9 250 97.9

3. Allocation of Frequencies for FM Broadcast StationsChannel No.

Frequency (MHZ)

Channel No.Frequency

(MHZ)251 98.1 276 103.1252 98.3 277 103.3253 98.5 278 103.5254 98.7 279 103.7255 98.9 280 103.9256 99.1 281 104.1257 99.3 282 104.3258 99.5 283 104.5259 99.7 284 104.7260 99.9 285 104.9261 100.1 286 105.1262 100.3 287 105.3263 100.5 288 105.5264 100.7 289 105.7265 100.9 290 105.9266 101.1 291 106.1267 101.3 292 106.3268 101.5 293 106.5269 101.7 294 106.7270 101.9 295 106.9271 102.1 296 107.1272 102.3 297 107.3273 102.5 298 107.5274 102.7 299 107.7275 102.9 300 107.9

4. Classes of FM Broadcast Stations

• 4.1 Class-A Stations– Transmitter power in between 10 kW to 25 kW– Maximum of 125 kW ERP– Maximum of 2,000 ft. above ave. terrain– Only allowed in Metro – Manila and Metro – Cebu

Examples of Class-A Stations

4. Classes of FM Broadcast Stations

• 4.2 Class-B Stations– Transmitter power in between 1 kW to 10 kW– Maximum of 30 kW ERP– Maximum of 500 ft. above ave. terrain

Example of Class-B Station

4. Classes of FM Broadcast Stations

• 4.3 Class-C Stations– Non-commercial, community station– Maximum of 1 kW ERP

4. Classes of FM Broadcast Stations

• 4.4 Class-D Stations– Educational stations– Maximum of 10 W transmitter power

• 4.5 All classes of FM stations shall be protected to the 1 mV/m contour or 60 dBu contour.

4. Classes of FM Broadcast Stations• 4.6 Table of Assignments– The frequency assignments for the cities of

Manila, Laoag, Legaspi, Cebu, Davao, and Zamboanga.

Channel Frequency (MHz) Channel Frequency (MHz)202 88.3 254 98.7206 89.1 258 99.5210 89.9 262 100.3214 90.7 266 101.1218 91.5 270 101.9222 92.3 274 102.7226 93.1 278 103.5230 93.9 282 104.3234 94.7 286 105.1238 95.5 290 105.9242 96.3 294 106.7246 97.1 298 107.5250 97.9

4. Classes of FM Broadcast Stations

• 4.7 Radio Frequency Protection Ratios– 4.7.1 The ff. RF protection ratios provide 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 (KHz) R.F. Signal Ratio

0 60dBu : 15dBu

200 60dBu : 53dBu

400 60dBu : 80dBu

4. Classes of FM Broadcast Stations

– 4.7.2 Intermediate frequency amplifiers of most FM broadcast receivers are designed to operate on 10.7 MHz. For this reason the assignment of two stations in the same area, one with a frequency 10.6 or 10.8 MHz 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. Classes of FM Broadcast Stations

– 4.7.4 The nature and extent of the protection from interference accorded the FM broadcast 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.