Republic of the Philippines

University of Southeastern Philippines

COLLEGE OF ENGINEERING

Obrero Campus, Davao City

ECE523

Broadcast Engineering and Applied Accoustics

Commercial AM Station

Project Proposal

Submitted by:

Lorilla, Franch Maverick A.

Altivo, Jan Rey R.

Submitted to:

Engr. Joey dela Cruz

January 20

Objectives:

a. To propose an AM broadcasting station with the following specifications:

› Has an operating power of 10kW

› Performing a Class II-A operation

› With Service area requisites of 4.47 mV/m and 100uV/m for primary and

secondary respectively.

b. To recognize different factors to be considered in selecting a feasible location for

an AM Broadcasting Station.

c. To Distinguish and pursue the NTC’s rules, regulations and requirements in the

construction of an AM Broadcast Station.

d. To establish different parameters in the construction of AM Station acoustic rooms.

e. To choose and classify the different equipment to be used in the operation of an

AM Broadcasting Station.

f. To provide and establish a feasible AM broadcasting a feasible AM broadcasting

system in Davao city.

g. To provide Am in delivering the latest news and traffic to public

h. To design an AM broadcast system operating at 777 kHz with the call sign DXAL

i. To set up an efficient and cost effective broadcasting system with an overall

system reliability of 99.999%

Scope and Limitations

a. This proposal is only limited to the AM broadcast design located in Davao city.

Hence, the company will be responsible in propagating of signals for AM.

b. The cost analysis of the materials to be used in this study covers the only the main

equipment required in setting up the broadcast antenna such as the tower,

transmitter, receiver, transmission line and generators.

c. Hence, the budget considerations for miscellaneous equipment such as furniture,

office supplies and other devices are not part of this study.

d. The distribution of the services to the subscribers are outside the scope of this

study.

INTRODUCTION

Radio is one of the best means of communication today. Radio broadcasting has

enabled distant communication. Today, there are a vast number of radio stations around the

globe broadcasting by means of transmission. Today, the process of broadcasting is not

complicated at all since all the essential equipments are easily available. Radio broadcast or

broadcasting is just an audio form of communication. Broadcasting encompasses many

technologies which combine to create a method of transmitting content and/or data. One of the

traditional radio broadcasting still used today is AM.

Amplitude Modulation (AM) is a way of broadcasting radio signals. It transmits the

information in the form of electromagnetic waves. AM works by modulating (varying)

the amplitude of the signal or carrier transmitted according to the information being sent, while

the frequency remains constant. 

The Radio Broadcasting Industry in the Philippines has gone through numerous

deviations throughout its nearly eight decades of history. From its fetal stages of pure

entertainment, to its adoption of its role as a tool for information in the late 40s.

Today, Davao City has five AM Radio Stations: 576 AM- Bombo Radyo Davao, 621 AM-

RMN Davao, 1125 AM- Super Radyo Davao, 1296 AM- Radyo Patrol Davao, 1404 AM-

Kingdom Radio.

DESIGN BACKGROUND

The to be established AM station, DXJC 1287 kHz, is a Japanese alternative/variety

serving mainly in  Damosa Gateway, Lanang, Davao City, Davao del Sur with a power of 2500

watts. The station's studio, as well as the transmitter, will be assembled in the fifth floor of the

MKD- Mindanao Kokusai Daigaku-Mindanao International College building in the PNJK

Compound Mamay Road, Lanang, Davao City. DXJC will operate 16 hours a day, from 8

o’clock in the morning until midnight, 7 days a week.

Design Concept

Proposed AM Station:

Station Logo

Company

DXAL Japan Broadcasting Network

Owners

Engr. Franch Maverick A. Lorilla

Engr. Jan Rey Altivo

Call Sign

DXAL

Frequency Allocation

1777 kHz

Type

Japanese

Alternatives/ Variety

Power

2500 W

Transmitter Tower

Monopole Type

Tower Height:

100 m

Equipment Brand

Broadcast Electronics and etc.

Station Specifications

Station Name: Radyo Hapon

Station Parameters

Frequency

777 kHz is used which is within the high end of the standard medium wave band

frequency parameters (530 – 1605 kHz) to provide shorter antenna height. (Antenna height is

inversely proportional to frequency)

Transmitter Power

A 2500 watts transmitter is used to cover a 100 km area of coverage which is from the

PNJK Compound Mamay Road to the boundaries of Davao del sur.

Tower

Tower height is calculated using the formula {(c/f)/4} x 98%. Thus getting a height of 100

m. A mast radiator (or 'radiating tower') is a radio mast or tower in which the entire structure

functions as an antenna. This design is commonly used for transmitting antennas operating at

low frequencies, in the VLF, LF and MF ranges, in particular those used for AM broadcasting.

The metal mast is electrically connected to the transmitter. Its base is usually mounted on a

nonconductive support to insulate it from the ground. A mast radiator is a form of monopole

antenna.

Antenna

The station uses a monopole antenna which is a class of radio antenna consisting of a

straight rod-shaped conductor, often mounted perpendicularly over some type of conductive

surface, called a ground plane. A monopole has an omnidirectional radiation pattern. That is it

radiates equal power in all azimuthal directions perpendicular to the antenna, but the radiated

power varies with elevation angle, with the radiation dropping off to zero at the zenith, on the

antenna axis. It radiates vertically polarized radio waves. Thus a quarter-wave monopole, the

most common type, will have a gain of 5.19 dBi and a radiation resistance of about 36.8 ohms if

it is mounted above a good ground plane.

Station Location

The station, as well as the transmitter, will be located at the fifth floor of the MKD-

Mindanao Kokusai Daigaku-Mindanao International College in the University of PNJK

Compound Mamay Road, Lanang, and Davao City.

The area of coverage will be mainly Bo. Obrero, Davao City with a land area of

approximately 100 km.

Area of Coverage:

AM Tower Calculator

Centre Site         

Antenna Height (m)

Antenna Type    

Mobile Antenna Height

(m)

Mobile Antenna Gain

(dBi)

Description

Frequency (kHz)

Required reliability (%)

System of Designing

MKD- Mindanao Kokusai Daigaku-Mindanao International College

100

Omni

2

2

MKD- Mindanao Kokusai Da

777

99.999

i. Equipment Configuration

ii. Transmitter Design

ANTENNA

ANTENNA TUNER

SWR/POWER METER

TRANSMITTER

STUDIO-TRANSMITTER

LINK

AUDIO MIXING CONSOLE

LOUD SPEAKER TELEPHONE HYBRID MICROPHONE CD PLAYER TURNTABLE

a.) RF Oscillator stage

- This stage produces the carrier frequency of the AM Station. The oscillator is a

Crystal oscillator made of resonant quartz crystal.

b.) Buffer

- Buffer amplifier is used to match the output impedance of the oscillator to the input

impedance of the frequency multiplier.

c.) Frequency Multiplier

- This generates higher harmonics of the oscillator carrier frequency, it is a tune circuit

that can be tuned to the requisite carrier frequency that is to be transmitted, which is

777 kHz.

d.) Power Amplifier

- It is a class C amplifier that gives high power current pulses of the carrier signal at its

output. It is a high-level transmitter.

e.) Audio driver and Audio power amplifiers

- The audio driver amplifier amplifies the audio produced at the station, it is then power

amplified by a class A or B power amplifier.

f.) Modulated Power Amplifier

- This is the output stage of the transmitter. The class C amplifier amplifies the power

of the AM signal to the reacquired transmitting power, which is 2.5 kilowatts. This

signal is finally passed to the antenna, which radiates the signal into space of

transmission.

iii. Sound Reproduction

Our station will be using monaural sound reproduction, often referred to as

monophonic sound or simply mono, which is practical since we use voice frequencies

most of the time. Monaural sound reproduction typically has only one microphone or

speaker, in the case of multiple sound sources, a common signal path will be used

where all the sound sources are fed.

iv. The Antenna

a. Radiating Element

The radiating element should be constructed vertically and made as tall and "fat" as

possible. If the length of the radiating element falls short of being a full quarter

wavelength at the operating frequency, a capacitive "hat" should be added. This makes

the antenna look longer electrically and thus improves radiation efficiency.

Output Power = 2.5 kilowatts (ERP)

Operating Frequency = 1287 kHz

Field Strength at 100 km = (√1.64 ∙ ERP) ∙377

d ∙2∙√ π=2.025/106.347

=0.019 mV/m

b

This is the radiation pattern for a 20dBi omnidirectional antenna, the most practical one for our

application. This makes the shape of a donut. As long as you are inside of the red lines you

have a 20 dBi gain, but if you get outside of the line you have no reception. This means that you

can fly twice as far away from yourself as long as you don’t fly outside of the reception field.

b. Grounding System

Eight evenly-spaced radial wires 43 meters in length

Buried 6-8 inches below ground

Grounding is another important factor that will give the station a better coverage. In this design,

we will use a large number of radial wires, defined as 120 radials, 90 electrical degrees in

length, composed of #10 soft-drawn bare copper wire buried at least six to eight inches

underground.

Studio Design

MARKETING, ADVERTISING AND PROMOTIONS

Radio Advertising Rates:

a.) Blocktime rates

Per Hour- 1,500/ broadcast

Package price: Monday- Friday, 15,000/month

Per Half Hour- 750/ broadcast

Package price: Monday- Friday, 7,500/month

b.) Tape Ads (Recorded Materials)

30 Seconds- 500/ Spot

Package Price: 10, 000/month (4 Spots/Day)

COSTS AND BUDGETING

Listed in the table are the components used in the installation process which also includes the

System Commissioning and Labor Cost. The total landed cost is inclusive of the Value Added

Tax (VAT).

Item

No.

Description Unit Qua

ntity

Price Amount

1HAR DAX 5- 1PH AM 5kw Digital

transmitter – Single PhasePcs. 1

1,643,219.0

01,643,219.00

2

LDF4 -50A, Andrew HELIAX Low

Density Foam Coaxial Cable,

Corrugated Copper, ½ in. black PE

Jacket

Feet 172 131.50 22,619.90

3 Isotron ISO-AMB-225 Low Power AM

Broadcast Band AntennaPcs. 1 20,061.00 20,061.00

4Behringer SX3040 Sonic Exciter Sound

Enhancement ProcessorPcs. 1 9,458.10 9458.10

5 Behringer EuroCom SPL3220

Multiband Processor/ LimiterPcs. 1 8,916.00 8916.00

6 Behringer HPS5000 Closed-Type High- Pcs. 2 1,337.50 2675.00

Performance Studio Headphones

7Behringer DDX3216 Digital Mixing

ConsolePcs. 1 23,270.75 23,270.75

8 TFT PACKAGE 5200 Composite/Mono

STL Transmitter/Receiver SystemPcs. 1 168,334.00 168,334.00

9 LMR-400-75 type N male plugs and

groundingPcs. 2 6,600.00 13,200.00

10Yamaha HS8 Active Studio Monitor

Speaker System 2Way Black Powered

Pro Audio

Pcs. 1 14,221.00 14,221.00

11 Electro Voice RE320 Dynamic

MicrophonePcs. 2 13,329.50 26,659.00

12 4 AWG Solid Bare Copper Wire200ft.

Spool4 11,124.80 44,499.20

13 Honda EB10000 Generator Pcs. 1 240,729.80 240,729.80

Building Rent Months (1) 27000.00 27000

AM Station outer and inner Construction 750,000.00 750,000.00

Labor 452,229.00 452,229.00

TOTAL COST 3,467,091.75

RETURN ON INVESTMENT

I, Overall Investment = Php 3,467,091.75

G, Gain from investment:

Average gain from radio advertising approximately = t*a

Where: t = advertising airtime in s

a= average radio advertising rate

G=t*a = 6hrs(3600s/hr) * 1000/60s

G = 360,000

ROI=-{[(I-G)/I] -1}

= (3,467,091.75 –360,000)/ 3,467,091.75)

= -(0.8961 -1) x 100%

= 10.38% on daily basis

ROI=-{[(I-G)/I] -1}

= ((3,467,091.75 –360,000*30)/ 3,467,091.75)

= -(-2.11 -1)

= 3.11 monthly basis