CETEC Sparta 625A Manuel utilisateur

www.SteamPoweredRadio.Com

Model 625A

FM

Transmitter

NUAt.

c

~~~r~

~oS~

~~8rEE

==--

www.SteamPoweredRadio.Com

I

,,...

-----------------....."'II

I

TECHNICAL

MANUAL

Model

625A

FM

Transmitter

PROPRIETARY

NOTICE

Sparta Electronic

Corporation

proprietary

data

is

contained

herein.

Neither

this

document

nor

the

information

contained herein shall be disclosed

to

others

for

manufacturing

or

any

other

purpose except

as

authorized in

writing

by

Sparta Electronic Corporation.

C1974

098-7042 25.00

!5B!51

FLORIN·P

AKIN

ROAD

ACRAM

NTC,

CALIFORNIA

A OIVI

IO

N Of

CO

M

..

U

T[R

(

QUl,.M(NT

CORl'ORATION

aa

www.SteamPoweredRadio.Com

I

WARNING

THIS UNIT CONTAINS HIGH

VOLTAGE,

HIGH CURRENT

POWER

SUPPLIES.

Potentials up to 8000 volts* at lethal

current

levels are present and exposed to mainte-

nance personnel working with power

on

and

interlocks defeated.

When maintenance requires

working

with

power on and

unit

open, exercise extreme

caution. Stand on insulated surface. Work

with only one hand inside unit. Use only high

voltage insulated tools. Have second person

standing by at all times.

*

Depending upon

transmitter

being used.

~(p~Lf~

ELECTRONIC CORPORATION

www.SteamPoweredRadio.Com

I

·I

I

Model

625A

TABLE

of

CONTENTS

Section

I

GENERAL

INFORMATION

.•....•.•..•••••••••••••••••••••••••••

l-1.

INTRODUCTION

....••.•••••.••••••..••.•••••••••••.••••

l-2.

GENERAL

DESCRIPTION

•••••••••••••••••••••••••••••.•••

l-2

.1.

Physical

Characteristics

•••••••.•.••..••••.••••••

1-2.2.

Functional

Characteristics

••••••••.••••••.••.••••

l-3.

MODULE EQUIPMENT

•••.••.•••••••••.••••••••••••••••••

II

INSTALLATION

..••••••••••••••.•••••••••.•••••.•••••••.••••••

III

IV

098-7042

2-1.

INSTALLATION PLANNING

••••..•••••••.••••••.••••••••••

2-1.

l.

Environmental

Requirements

..•...•.•••••.••••••••

2-1.

2.

Space

Requirements

••.••••••••..•••••••.•••.••••

2-1.3.

Power

Requirements

•.••••••••••..•••••••••••••••

2-1.

4.

Cooling

Requirements

..••••.•.••••••••••••••••••

2-2.

UNPACKING

AND

INSPECTION

•••.•..•••..•••••••.••..•••

2-3.

HIGH

VOLTAGE

POWER SUPPLY INSTALLATION

•••••••.•••••.

2-3.

l.

Model

602A

Driver

•....•••.•.••••••.••.••.••••••

2-4.

INPUT

AND

OUTPUT CONNECTIONS

..••••••••••••••••••••

2-4.

l.

RF

Input/Output

Connections

•••••••••••••••••••••

2-4.

2.

PA

Primary

Power

and

Grounding

•••••••••.••••••••

2-4

.3.

Driver

Primary

Power

••••••••••••.•••••••••••.•••

2-4

.4.

Exciter

Input

Signal

Connections

.••••••••••••••.••

2-4.

5.

Cabinet

Interconnections

••..••••••••••••••..••••

2-4.

6.

PA

Tube

Installation

...••••.•••••••••••••••...•.

2-5.

REMOTE

CONTROL CONNECTIONS

.•••..••.•••••••••.••••

2-5

.1.

Stereo/SCA

Remote

Control

••.•.•••••••••••••••••

2-5.

2.

PA

Remote

Control

•••.••••.•••••••••.••••••.•.•.

2-5.

3.

PA

Remote

Metering

.••••••••••••••••••••••••••••

2-5

.4.

Driver

Section

••••••.••••••••••••••••••••••••••

OPERATION

••.••••••••••.••.••••••.••••••.•••••••••••••••••

3-1.

PA

CONTROLS AND INDICATORS

•••••.•••••.•••••••••••••

3-1.1

Driver

Section

••.•.•••••••••••••••.•••••••••••••

3-2.

INITIAL TURN-ON PROCEDURES.

••.•••••••.•.••.•••.•••••

3

-2

•l ,

Preliminary

Che

ck

s

••••.••••••.••••••••••••••.••

3-2.

2.

Initial

Turn On

...•.••••.•••••.••••••••••••.•••.

3-3.

TUNING PROCEDURE

.••..••••••••••••••••••••••.•••••••

PRINCIPLES OF

OPERATION

•••••.•••••••••••••••••••••••••••••

4-1.

GENERAL

••..•••..•••••.••••.•••••.••••.••••••••••••.•

4-2,

CONTROL

AND

OVERLOAD

PROTECTION CIRCUITS ,

.•••.••••

4-3.

OVERLOAD

AND

AUTOMATIC

RECYCLE

CIRCUITS

••.•••.••••

4-4.

POWER SUPPLIES

••..••..•....•••••.••••••••••••••

,

••.•

4-5.

RF

AMPLIFIER CIRCUIT

ANALYSIS

..•••••••••.•••••••••••••

4-6.

METERING CIRCUIT

ANALYSIS

.•••••••••.•.••••••••••••••

4-6

.1.

PA

Meter

Circuits

••.•••••••••••••••••••••••••••

Front

Matter

l-1

1-2

l-2

l-4

2-l

2-1

2-l

2-1

2-4

2-6

2-7

3-l

3-5

3-6

3-7

4-l

4-1

4-2

4-3

4-4

www.SteamPoweredRadio.Com

Model

625A

Section

V

VI

Figure

2-1

2-2

2-3

3-1

3-2

3-3

3-4

3-5

3-6

3-7

3-8

3-9

3-10

3-11

5-1

5-2

5-3

5-4

098-7042

4-7.

4-6.2.

4-6.3.

Power

Output

and

VSWR

measurement.

•.•.•.•••••••

PA

Filament

and

Elapsed

Time

Meter

Circuit.

•••....

POWER CONTROL

•••••.•...••••.•.••••••••••.••••.••..•

MAINTENANCE

•••.....•••.•••••••••••••.•.•.•••••••••••••••

5-1.

PERIODIC INSPECTION AND MAINTENANCE

••.••.•.•••••••

5-1.1.

Air

Filters

•••.••.••.•••••••••.•••••••••••.••••

5-1.

2.

Anode

Coolers

•...•...•.•.•..••.•..••..••.••.••

5-2.

REMOVAL

AND REPIACEMENT

OF

AMPLIFIER

TUBES

•••••••.•

5-3.

OVERLOAD

REIAY

ADJUSTMENT

.•..••..•••.••••••...•••.•

5-3.

1.

Driver

Section

Overload

Relay

Adjustment

•..••••.•

5-3.

2.

PA

Grid

Overload

•..••..••.••••••••.•••.•••••••

5-3

.3.

PA

Plate

Overload

............................

.

5-3

.4.

Automatic

Power

Control

Adjustment

•••.••••.•••••

5-3.

5.

VSWR

Adjustment

•.•••••.••••••.•••.•••.•••.•••

REPIACEABLE

PARTS

6-1.

ORDERING INFORMATION

•••••.•••••••.•.•••••••••••••••

6-2.

PARTS

LOCATION

•.••..•..•••••••••••••••••••••••••••••

6-3.

TABLES

OF

REPLACEMENT

PARTS

••••••••••.••••••••••••••

LIST

of

ILLUSTRATIONS

Title

Model

625A

FM

Transmitter

-

Top

View -

Floor

Space

•••••••••••.

Model

625A

FM

Transmitter

Front

and

Side

View

.••••..•.•••..•••

H.

V.

Transformer

-

T-203

••••••.••••••••.•••••••••••••.•.•••

Front

View -

Component

Location

.••.•.•••.•••••••••••••••••••

Control

Chassis

-

Component

Location

•••..•..••••••.••••••••.

VSWR

Protedtion

Board,

Automatic

Power

Control

Board,

Motor

Driver

Board

...••••••••.••..••••.•••••••••.••••••••.••.•••

Base

Plate

Assembly

•••..•.•••..•••.•••.••.•.•••••••••••.•••

Resistor

Panel

.•••••••••••••••.••••••••••••••••••••••••.•••

Contactor

Panel

.••.•••••••••••••••••••.••••••••••••••.•••••

Transformer

Va

ult

••••••.••••••.••••..••••••.••.•••••.•..•••

Al-A2-A3

Mother

Board

....•...•.•••..•••••••.••••••••.•••••

Al Board -

VSWR

Protection

Circuit

••......•.••••••••.••••••••

A2

Board -

Automatic

Power

Control

.••••••.•••.•.•.•••.•••••••

A3

Motor

Driver

.••.•....•.....•.••.••...•...••..•••..•.••••

Schematic

Diagram

RF

and

Power

Supply

Section

(071-0263)

••••••

Schematic

Diagram

Control

Ladder

and

Overload

Sect

(071-0265)

••

Model

602A FM

Transmitter

used

as

625A

Driver

(071-0264)

••••••

Control

Ladder

(O

71-0191-02)

••••••••.•••••••••••••••••••••••

Front

Matter

Page

4-5

5-1

5-2

5-3

6-1

2-2

2-3

2-5

3-2

3-11

3-12

3-13

3-14

3-15

3-16

3-17

Attachment

Attachmert

iv

I

www.SteamPoweredRadio.Com

I

I.

I

Mo

del

6

25

A

TA

BL

E

1-1

1-2

3-1

3- 2

3- 3

6- 1

6- 2

098-7042

{

LIST

of

TAB

L

ES

Titl

e

Phys

ica

l

Charac

t

eristics

.•..

.

•..••.•••••••.••••••••••.••••••••

Fu

nc

tio

n

al

Characteristics

•.•.••••.••••.••••.••••••••••••••••••

O

perating

Controls

and

lndicators

-

PA

Secti

on

•...•..••••••••••••

Typi

ca

l

Operating

Voltages

and

Currents

•••••••••••••••••••••••••

Effi

ciency

Curve

••••.••••.•••••••••••••.•••.•••••••••••••••••

List

of

Manufactures

••.••••..••••.••.••.••••.•••.•••••••••••.•

Re

pl

aceable

Parts

List

••.•

•

•••••••••••••••••••••••••••••••••••

'

Front

Mat

ter

1-2

1- 3

3- 3

3-9

3-10

6- 2

6-

3

V

www.SteamPoweredRadio.Com

I

Model

625A

1-1

. INTRODUCTION

SECTION I

G

ENERAL

INFORMATION

Section

I

This

manual

contains

information

required

to

install,

operate,

and

maintain

the

SPARTA

Model

625A

FM

Transmitter.

Section

I

describes

the

transmitter

and

lists

its

specifications,

Section

II

provides

installation

instructions,

Section

III

contains

operating

procedures

and

Section

IV

describes

the

principle

of

operation.

Maintenance

procedures

and

troubleshooting

diagrams

are

contained

in

Section

V,

and

replaceaole

parts

are

identified

and

listed

in

Section

VI

. A

complete

operating

and

servicing

manual

covering

the

Model

680

FM

Exciter

and

Model

602

FM

transmitter

is

provided

separately

.

1-2.

GENERAL

DESCRIPTION

The

Model

625A

FM

Transmitter

(Figure

2-2)

provides

an

output

of

25

kilowatts

in

the

frequency

range

from 88

to

108

MHz,

and

is

type-accepted

by

the

Federal

Communications

Commission

under

Part

73,

Broadcast

Services.

As

shown

in

figure

1-1,

the

transmitter

consists

basically

of

three

sections

. The

left-hand

section

contains

the

FM

exciter

and

driver,

together

with

associated

metering,

control

and

power

circuitry.

This

section

is

denominated

DRIVER

throughout

this

instruction

book

and

consists

of

a

complete

and

independent

one

2.5

K:N

transmitter,

model

602A .

The

second

section

contains

the

power

amplifier

(PA)

and

its

associated

metering,

control,

and

high

voltage

filtering

components

. The

right-hand

section

is

the

transformer

vault

and

it

contains

the

plate

transformer,

H .

V.

rectifiers

and

contactors

plate.

The

PA

cavity

is

cooled

by

a

high-speed

blowers

and

each

of

the

two

cabinet

sections

are

scavenged

of

incidental

warm

air

by

ventilating

fans

. The

circuit

design

of

the

blower

furnishing

air

to

the

PA

cavity

is

such

that

it

will

continue

to

run

for a

preset

interval

after

the

transmitter

is

shut

down

to

remove

residual

heat.

The

Model

625A

design

includes

such

features

as

automatic

power

control

and

automatic

overload

recycling.

Once

the

transmitter

has

been

tuned

to

its

authorized

rated

power

output,

the

automatic

power

control

circuit

maintains

this

RF

output

level

regardless

of

mains

power

fluctuations.

The

overload

recycle

circuit

automatically

restores

the

transmitter

to

normal

operation

following

a

momentary

current

overload

in

the

monitored

circuits

.

Consecutive

recycling

is

limited

to

three

times

within

30

seconds

following

the

operation

of

any

overload

relay.

If

the

overload

exists

after

a maximum

of

3

recycles,

the

transmitter

high-voltage

circuits

will

remain

off

until

the

overload

is

reset

manually.

Tally

lights

mounted

on

the

driver

and

PA

control

panels

are

triggered

by

their

associated

overload

relay

.

These

lamps

will

remain

lighted

after

a

momentary

overload

to

identify

the

circuit

where

the

overload

occurred.

Only

three

transmitti

ng

tubes

are

used

in

the

high-level

stages:

a

4X150A

tetrode

(driver),

a 5CX1500A

pentode

(driver) ,

an

d a 3CX15000A7

triode

(PA).

RF

excitation

is

provided

by

the

Model

680

FM

Exciter,

which

is

an

all-solid-state

unit

that

provides

monaural,

stereophonic

and

Subsidiary

Communications

A

uthorization

(SCA)

modes

of

operation

in

accordance

with

FCC

and

international

standards.

The M

odulation

m

ethod

is

"direct

FM"

with

no

mixers

or

multipliers

after

the

modulated

oscillator

.

Connections

are

provided

to

allow

remote

transmitter

mas

ter

start,

plate

power

on-off,

and

power

trim.

Provisions

are

also

included

for

remote

metering

of

PA

pla

te

voltage,

plate

current

and

power

output.

098-7042

1

-1

www.SteamPoweredRadio.Com

Mcx:lel 625A

Section

I

1-2

.1.

Physical

Characteristics

Physical

characteristics

of

the

Mcx:lel 625A

excluding

the

Model

680

FM

Exciter,

are

given

in

table

1-1.

Physical

characteristics

of

the

Mcx:lel

680

and

Mcx:lel 602A

are

given

in

paragraph

1-2

.1

of

its

individual

operating

and

servicing

manual.

Table

1-1.

Physical

Characteristics

Cabinet

Dimensions:

Transformer

Vault:

Weight:

Cabinet

Style:

Input/Output

Connections

a.

RF

Output:

b.

Audio

Inputs:

Cooling

Provisions

a.

Driver

Cavity:

b.

PA

Cavity:

c.

Cabinet:

Ambient

Temperature:

Altitude:

Humidity:

1-2.

2.

Functional

Characteristics

75

inches

high,

68

inches

wide,

24

inches

deep

36

inches

high,

34

inches

wide,

24

inches

deep

2750

pounds

Two

enclosed

steel

cabinets;

access

provided

through

hinged

front

panels

and

rear

cabinet

doors.

One

transformer

vault.

3-V8

inch

coaxial

line

flange

Barrier

strip

One

1-phase

530 cfm

blower

Two

1-phase

530

cfm

blower

One

1-phase

750 cfm

fan

(PA

section)

One

1-phase

750 cfm

fan

(Transformer

vault)

To

50°

C,

(122°F);

continuous

duty

at

rated

power

output

To

7,500

feet;

continuous

duty

at

rated

power

output

0

to

95%

Functional

characteristics

of

the

Model

625A

excluding

the

Model

680

FM

Exciter,

are

given

in

table

1-2.

Functional

characteristics

of

the

Model

680

are

given

in

paragraph

1-2.

2

of

its

individual

operating

and

servicing

manual.

098-7042

I

www.SteamPoweredRadio.Com

I

·I

I

Model

625A

Section

I

Table

1-2.

Functional

Characteristics

,

Frequency

Range:

Type

of

Emission:

RF

Power

Output:

RF

Power

Output

Capability:

Output

Impedance:

VSWR:

Frequency

Stability:

Modulation

Capability:

RF

Bandwidth:

Harmonic

Attenuation:

FM

Noise

Level:

AM

Noise

Level:

Input

Line

Voltage:

Permissible

Line Voltage

Variation:

Power

Line

Input:

Tube

Complement:

Controls

and

Indicators:

Remote

control

and

Metering:

Overload

Relay

Protection:

098-7042

88

to

108

MHz

F3,

F9

frequency

modulation

25

Kilowatts

25

Kilowatts

maximum;

adjustable

down

to

17

kilowatts

as

measured

at

output

of

the

harmonic

filter

50

Ohms,

nominal

I.

7

5/1

maximum

~

1

KHz

~

7

S

KHz

(100%)

~

750

KHz

at

3

DB

points

-80

DB

minimum

below

carrier

amplitude

65

DB

below

100%

modulation

at

400

Hz

55

DB

rms

below

a

reference

of

100%

AM

carrier

200

to

250

vac,

3-pha

se,

60

Hz.

,

4-wire

(SO

Hz

on

special

order)

~

5%

from

nominal

39

KY-I

ml;lximum

at

0.

9

power

factor

One

4Xl50A;

one

SCXlS00A

(driver);

and

one

3CX1S000A7

See

table

3-1

Terminal

board

provided

for

remote

control

and

metering

connections

Overload

relays

protect

against

excess

current

in

the

following

circuits:

1.

DR

Plate

(Driver

Section)

2.

Final

Screen

(Driver

Section)

3.

Final

Plate

(Driver

Section)

4.

PA

Grid

1-3

www.SteamPoweredRadio.Com

Model

625A

Section

I

Table

1-2.

Functional

Characteristics

(Continued)

Overload

Indicators:

5.

PA

Plate

6.

VSWR

One

overload

indicator

and

six

overload

tally

lights.

(See

table

3-1)

Other

Protective

Devices:

Eight

Panel-mounted

fuses

and

two

internal

circuit

breakers.

Two

additional

fuses

mounted

on

rear

panel

of

exciter.

1-3.

MODULE EQUIPMENT

The

Model

680

FM

Exciter

is

standard

equipment

and

provides

the

capability

of

monaural

FM

operation.

The

following

units,

which

are

available

from

SPARTA

ELECTRONIC CORPORATION

provide

the

Model

625A

with

the

capability

of

stereophonic

and

SCA

operation:

a.

Stereo

Generator

-

Model

682

b.

SCA

Generator

-

Model

683 (41

or

67

KHz)

When

operating

in

the

monaural

mode,

the

41

KHz

and

67

KHz

SCA

units

may

be

used

individually

or

simultaneously.

When

operating

in

the

stereophonic

mode,

the

41

KHz

generator

must

be

muted.

However,

the

67

KHz

generator

can

be

used

in

combination

with

the

stereo

generator

in

any

mode

of

operation

without

program

interruption

if

an

optional

5 KHz

filter

kit

is

installed.

The 5 KHz

filter

kit

(091-5971-01)

may

be

specified

for

initial

installation

by

SPARTA

ELECTRONIC

CORPORATION

or

it

can

be

added

to

the

SCA

module

at

a

later

date.

The

kit

consists

of

a

low-pass

filter

which

limits

the

SCA

input

band-width

to

5 KHz.

In

addition

to

the

input

filter,

the

sub-carrier

deviation

should

be

limited

to

6%

to

avoid

interference

with

the

stereo

channel.

098-7042

1-4

I

CETEC Sparta 625A Manuel utilisateur

Manuels Émetteur populaires d'autres marques