Kenwood TM-731A Manual de usuario

TM-731A/E

|

KENWOOD

SERVICE

MANUAL

PRINTED

IN

JAPAN

B51-8015-00(T)1349

Knob

(K29-3111-04)

x3

Metalt

b

(Top)

:

*

etallic

cabinet

(Top.

wecpnen®”

(A01-1076-02)

Knob

(K29-3111-04)

x3

Panel

ass’y*

(A20-)

Knob

(SQ)

{K29-31

16-04)

Knob

(AF)

(K29-3115-04)

Panel*

Knob

(Main)

(K29-3060-04)

Knob

{K29-3112-04)

x5

Knob

(Up/Down}

Knob

(F)

Knob

(Button)

Metallic

cabinet

(Bottom)

(K29-3114-04)x2

|

(K28-3143-04}

(K27-3026-04)

x

2

(AQ1-1048-02}

Knob

(Sub-Encoder)

Knob

(Button)

Knob

(LOW)

(K29-3145-04)

(K27-3028-04)

(K29-3144-04)

*Refer

to

parts

list

on

page

25.

Photo

is

TM-731A.

CONTENTS

CIRCUIT

DESCRIPTION

..0......ccceeceecseeesteaseesnessteesen

CONTROL

UNIT

(X53-3250-XX)

oes

seceeeeseeseeeeerreees

66

DESCRIPTION

OF

ELEMENTS

__

144

MHz

TX-RX

UNIT

(X57-3400-XX)

veeeseesseersereens

68

PARTS

LIST...

ccscccesesessesssvseesess

w25

430

MHz

TX-RX

UNIT

(XB7-3390-XX)

oo.eeceeeeeeees

70

EXPLODED

VIEW

.000.0...cccssseccessesensereesessesseeseeseesees

FINAL

UNIT

(430

MHz)

(X45-3340-XX)

oes

72

PACKING

.......csccsscessesssesesseeeeeeseseessneesessneeseeseeneenes

FINAL

UNIT

(144

MHz)

(X45-3340-XX)

oe

cseeeseesenne

73

ADJUSTMENT

20.0.0...

ceeccccesseesseeneecsesestesaesesecsnsaneens

53

LEVEL

DIAGRAM

.........scscssssssesseseereeseeeeeseentieeetenss

74

TERMINAL

FUNCTIONS

....0.....cscscccssessseesseesesteesees

60

SCHEMATIC

DIAGRAM..........scssecsessceeeeesesseseeneeteaes

75

PC

BOARD

VIEW/SCHEMATIC

DIAGRAM

BLOCK

DIAGRAM

.0.......ssccsesssssseestsseeneeeeeeeeeeteneonsees

79

144

MHz

PLL

UNIT

(X58-3660-00)

(M,W)

...cececeees

63

TSU-6

(CTCSS

UNIT)...

..ccscscessessescneaeeeenceteeevensense

81

144

MHz

PLL

UNIT

(X58-3670-10)

(K,P)

..scecesceesees

64

SPECIFICATIONS.

........ssccscsseessseseeseesceeeneeees

Back

cover

430

MHz

PLL

UNIT

(X58-3680-00)

oo...

eerste

65

TM-731A/E

CIRCUIT

DESCRIPTION

Frequency

Configuration

The

TM-731A/E

uses

a

synthesized

PLL

and

includes

a

vari-

ablefrequency

oscillator

that

enables

selection

of

5

kHz,

10

kHz,

12.5

kHz,

20

kHz,

or

25

kHz

channel

steps.

(See

Fig.

1.)

Signals

received

in

the

144

MHz

band

are

down-converted

to

a

first

intermediate

frequency

of

10.7

MHz

(M,W)

and

16.9

MHz

(K,P)

by

mixing

with

the

first

local

oscillator

frequen-

cy

(133.3

MHz

to

135.3

MHz

(W),

127 MHz

to

131.100

MHz

(K,P),

133.3

MHz

to

137.30

MHz

(M)),

and

then

to

the

se-

cond

intermediate

frequency

of

455

kHz

by

mixing

with

the

second

local

oscillator

frequency

of

10.245

MHz

(M,W)

and

17.355

MHz

(K,P).

Signals

received

in

the

430

MHz

band

are

down-converted

to

the

first

intermediate

frequency

of

30.825

MHz

(M,W)

and

21.6

MHz

(K,P)

by

mixing

with

the

first

local

oscillator

frequen-

cy

(399.175

MHz

to

409.175

MHz

(M,W),

416.400

MHz

to

428.400

MHz

(K,P)),

and

then

to

the

second

intermediate

fre-

quency

of

455

kHz

by

mixing

with

the

second

local

oscillator

frequency

of

30.37

MHz

(M,W)

and

21.145

MHz

(K,P).

Dou-

ble

conversion

is

thus

used

for

both

the

144

MHz

and

430

MHz

bands.

The

transmitted

signal

for

both

bands

is

generated

direct

os-

cillation

and

direct

frequency

division

in

the

phaselocked

loop.

The

signal

is

amplified

by

a

linear

amplifier

before

being

ap-

plied

for

the

antenna.

Unit

Model

|

TM-731A

(K.M,P)

|

TM-731

(W)

Final

Unit

eee

sotoot

hy,

|

%45-3340-61

Control

Unit

One

as

a

X53-3250-61

430

MHz

TX-RX

Unit

00.71

ne

X57-3390-21

144

MHz

TX-RX

Unit]

SA

Min

|

X87-8400-61

|

Table

1

Comparison

of

TM-731A

and

TM-731E

CFW455F

144~

147.995

MHz

(K,M,P)

_144~145.995

MHz

(W)

=

.

MCF

455

kHz

16.9

MHz

{K,P)

ist

MIX

10.7

MHz

(M,W)

ANT

SW

RF

AMP

MIX,

IF,

DET

ca

-.

|

10.245

MHz

(M,W)

17.355

MHz

(K,P}

127.1~

131.095

MHz

(K,M,P)}

133.3~

137.295

MHz

(M)

;

133.3~

135.295

MHz

(W)

sp

144

MHz

STEREO

BAND

PLL

AF

AMP

PA

TX

AMP

SYSTEM

anaLocue

sw

|

|oo

144~

.

[oil

Lahey

JACK

145.998

MFZ

(Wr

ae

in

ee

eel

4144~

147.995

MHz

(K,M,P}

|

MAIN

2-S

T

{

a

Ae

439.

"995

MHz

(M,W!

438349905

Mie

KK,

P)

reha|

SUB

PA

TX

AMP

430

MHz

.

BAND

PLL

MIC

AMP

438~

SYSTEM

449.995

MHz

(K,M,P)

399.175-

MIC

430~

409.17

MHz

(W)

439.995

MHz

(W)

416.400

~

428.395

MHz

(K,M.P)

MCF

21.6

MHz

(K,P}

CFW455F

30.825

MHz

(MW)

455

kHz

ANT

SW

RF

AMP

MIX,

IF,DET

Ist

MIX

=

0.370

MHz

(MW)

1.145

MHz

(K,P)

Fig.

1

Frequency

Configuration

TM-731A/E

CIRCUIT

DESCRIPTION

Receiver

Circuits

*

General

This

set

uses

seperate

receiver

circuits

for

the

144

MHz

and

430

MHz

bands.

These

circuits

extend

from

the

antenna

in-

put

section

to

the

IF

detector.

e

144

MHz

The

incoming

two

meter

band

signal

passes

thru

the

trans-

mit/receive

switching

diode

in

the

final

unit.

And

then

through

the

antenna

matching

coil

in

the

front

unit.

It

is

then

amplified

by

a

GaAs

FET

radio-frequency

amplifier,

Filtered

by

a

three-

stage

bandpass

filter

that

uses

varicap

tuning

to

reject

unwant-

ed

signal

components,

and

is

fed

to

the

first

mixer.

There

it

is

mixed

with

the

first

local

oscillator

signal

from

the

PLL

to

generate

the

first

IF

signal

(10.7

MHz

(M,W),

16.9

MHz

(K,P)).

Spurious

adjacent-channel

signals

are

removed

in

a

two-stage

MCF

(Monolithic

Crystal

Filter).

The

first

IF

signal

is

amplified

and

fed

to

the

FM

IF

IC:MC3361D.

This

IF

signal

is

mixed

with

the

second

local

oscillator

frequency

of

10.245

MHz

(M,W)

and

17.355

MHz

(K,P}

which

results

in

a

second

IF

signal

of

455

kHz.

Spurious

adjacent-channel

signals

are

removed

from

the

se-

cond

IF

signal

by

ceramic

filter.

Then

the

signal

is

amplified

Fig.

2

144

MHz

Front

End

[Varicap

Tuning)

PLL

OUT

¢

430

MHz

band

The

incoming

70

cm

signal

passes

thru

the

transmit/receive

antenna

switching

diodes

in

the

final

unit

and

then

passes

through

the

antenna

matching

coil.

The

signal

is

then

fed

to

a

two-stage

radio-frequency

amplifier

consisting

of

a

GaAs

FET

and

a

junction-type

FET.

It

then

passes

through

a

two-stage

two-cauity

helical

resonator

and

enters

the

first

mixer,

where

it

is

mixed

with

the

first

local

oscillator

signal

from

the

PLL

to

generate

the

first

IF

signal

(30.825

MHz

(M,W),

21.6

MHz

(K,P)).

Spurious

adjacent-channel

signals

are

removed

by

a

two-stage

MCF.

:

The

first

IF

signal

is

amplified

and

fed

to

the

FM

IF

IC

(MC3361D).

This

IF

signal

is

mixed

with

a

second

local

oscil-

lator

frequency

of

30.37

MHz

(M,W)

and

21.145

MHz

(K,P)

|Loss

——-

==.

which

converts

it

to

a

second

IF

signal

of

455

kHz.

Spurious

adjacent-channel

signals

are

removed

from

the

se-

cond

IF

signal

by

an

ceramic

filter.

The

signal

is

then

amplified

and

detected

to

generate

the

audio

signal.

Item

Specification

Nominal

center

frequency

|

30.825

MHz

Pass

bandwidth

Max.

+7.5

kHz

at

3

dB

Attenuation

band

width

|

Max.

+28

kHz

at

40 dB

Ripple

Max.

1.5

dB

Insertion

loss

Max.

3

dB

Guaranteed

attenuation

60

dB

or

greater

at

+1

MHz;

40

dB

or

greater

for

spurious

signal

Terminating.

impedance

1.4

kQ/1_

pF

Table

2

MCF

(L71-0270-05)

Characteristics

(430

MHz

TX-RX

Unit

XF1)

(M,T,W)

item

Rating

Nominal

center

frequency

(fo)

21.600

kHz

3

dB

bandwidth

+7.5

kHz

or

more

+25

kHz

or

less

at

40

dB

+45

kHz

or

less

at

60

dB

Attenuation

bandwidth

Guaranteed

attenuation

70

dB

or

more

within

+

1

MHz

(Sprious

response

35

dB

or

more)

.

80

dB

or

more

within

+

(910

kHz

+20

kHz)

Ripple

1.0

dB

or

less

:

2.0.dB.orless

.

pene

Input

and

output

im-

pedance

1

kQ/1

pF

Table

3

MCF

(L71-0227-05)

(430

MHz

TX-RX

unit

XF1)

(K,P)

Item

Specification

Nominal

center

frequency

455

kHz+1

kHz

6

dB

bandwidth

Min.

+6

kHz

(above

455

kHz)

50

dB

bandwidth

Min,

+12,.5

kHz

(above

455

kHz)

Ripple

(455

+4

kHz)

Max.

3

dB

Insertion

loss

.

|

Max.

6

dB

Guaranteed

attenuation

(455

+100

kHz)

Max,

35

dB

input-output

matching

2.0

ka

impedance

Table

4

Ceramic

Filter

CFW455F

(L72-0315-05)

Characteristics

(430

MHz

TX-RX

Unit

CF1,

144MHz

TX-RX-Unit

CF1)

item

Rating

Nominal

center

frequency

{fo}

16.900

kHz

3

dB

bandwidth

+7.5

kHz

or

more

+25

kHz

or

less

at

40

dB

+45

kHz

or

less

at

60

dB

Attenuation

bandwidth

Guaranteed

attenuation

70

dB

or

more

within

+1

MHz

(Sprious

response

40

dB

or

more)

80

dB

or

more

within

fo

—

{900~920

kHz)

Ripple

1.0

dB

or

less

Loss

1.5

dB

or

less

input

and

output

im-

pedance

1.8

kQ/O

pF

Table

5

MCF

(L71-0279-05)

Characteristics

—

TM-731A/E

CIRCUIT

DESCRIPTION

Item

Specification

Nominal

center

frequency

(fo)

10.7

MHz

Pass

bandwidth

Max.

fo

+7.5

kHz

at

3

dB

Attenuation

bandwidth

1)

Max.

+25

kHz

at

40

dB

2)

Max,

+45

kHz

at

60 dB

Guaranteed

attenuation

{|

70 dB

or

more

within

+1

MHz

40

dB

or

more.

spurious

80 dB

or

more

within

—

900

kHz

to

—

920

kHz

Ripple

Max.

1.

dB

Insertion

loss

Max.

1.5

dB

Terminating

impedance

3

kQ/0

pF

Table

6

MCF

(L71-0228-05)

Characteristics

(144

MHz

TX-RX

Unit

XF1)

©

AF

Unit

The

path

from

the

detector

output

to

the

AF

power

amplifier

input

consists

of

two

separate

identical

circuits

for

the

main

band

and

the

subband.

The

audio

signal

is

first

switched

by

an

analog

switch

into

the

AF

preamplifier

for

its

corresponding

band.

After

amplification,

the

signal

level

is

adjusted

by

a

two-

channel

electronic

volume

control

IC:M51523

which

is

con-

trolled

by

the

MAIN

VOLUME

and

BALANCE

controls

on

the

front

panel.

An

AF

low-pass

filter

then

removes

unwanted

high-

frequency

components,

separate

audio

signals

are

selected

to

speaker

mixed

or.

separate

mode

by

analogue

switch

circuit

which

is

amplified

by

the

STEREO

audio

power

amplifi-

er

before

being

applied

the

speaker.

(See

Fig.

3.)

®

Preamplifier

For

main

\F

detect

®

Squelch

amplifier

band

A.

=

LL

144M

:

|_.]

|

;

LPF

-

cam

For

main

band’

%

Fa]

ar.

IF

detect

_.

For'sub

band

-~

:

ac}

y

°

t+}

=

:

wou

|

Let

x

L

2

MN4066BS’

M51523AL

TC4053BE

®

Prearmpiifier

For

sub

@

Squeich

amplifier

band

Fig.

3

AF

Section

¢

Squelch

Circuits

independent

squelch

circuits

are

provided

for

the

main

band

and

subband.

These

circuits

receive

the

output

from

the

de-

tector,

remove

the

50

kHz

noise

component,

amplify

the

sig-

nal

with

two

transistor

stages,

and

rectify

it

by

means

of

a

diode

to

generate

the

squelch

control

signal.

After

DC

amplification,

the

control

signal

is

used

to

switch

the

main

and

sub

pream-

plifiers

on

and

off.

¢

S

Meter

Circuits

Independent

S

meter

circuits

for

the

144

MHz

and

430

MHz

bands

receive

signals

from

the

455

kHz

ceramic

filter,

amplify

if

in

two-stage

meter

amplifier,

and

rectify

the

resulting

signal

to

generate

a

DC

voltage.

The

microprocessor

converts

the

ana-

log

DC

voltage

to

a

digital

output

that

is

used

to

drive

an

LCD

bar

meter.

cr

R33

DIO

reas

Roe

M2

[cpu

+

-*

91

33pin

PTHO1

I

P33.P30

Fig.

4

144

MHz

S-meter

circuit

¢

Switching

of

Balance

Range

To

disable

the

BALANCE

control

in

the

single

mode,

the

con-

trol

voltage

range

of

the

BALANCE

contro!

is

switched.

This

switching

is

done

by

a

Low

signal

from

the

INH

(Inhibit)

of

the

microprocessor

that

turns

on

transistor

Q7

in

the

single

mode.

Since

the

center

voltage

of

the

balance

control

resistor

is

held.to.approximately.4.V,

the

voltage.

at

the

BAL

can-

not

exceed

4

V,

so

even

if

the

balance

VR

is

moved

to

the

SUB

position,

the

main

band

remains

unattenuated.

(See

Fig.

5

and

6.)

in

dual

band

mode.

"in

single

band

mode

5

}

MAIN

a

z=

:

=>

ca

S

a

f

8

5

!

6

3

!

2

|

o

oO

!

£

=

f

Pa

z

,

SUB

-B8o|

!

\

-ea

/

)

-

)

;

a

Voltage

at

BAL

(V)

Voltage

at

BAL

(V)

Fig.

5

Fig.

6

During

normal

operation,

the

two

electronic

volume

controllers

in

the

set

operate

using

the

M51523AL,

but

when

the

remote

control

unit

(RC-10)

is

connected

and

used

to

adjust

the

out-

put

level,

they

are

controlled

by

the

LC7532M.

When

the

remote

control

unit

is

connected,

a

High

switch

con-

trol

signal

is

sent

from

the

CE

of

shift

register

IC4

to

force

the

attenuation

of

the

M51523AL

to

zero.

(Normally

the

CE

output

is

Low.)

The

UP

and

DOWN

signals

from

the

shift

register

then

vary

the

attenuation

of

the

LC7532M.

(See

Fig.

7.)

TM-731A/E

CIRCUIT

DESCRIPTION

TX-RX

(430

MHz)

Unit

X57-3390-XX

Control

Unit

X53-3250-XX

A/3

AF

——>—41N2

ouT2

_

|

14

13

MAIN

!

1

aad

-

<

_

.

a

&

pal

>

Dé

av

Be

+f

a

nS

a

ou

~~

SUB

4

OUTI

Balance

VR

variable

AF——5

INI

i

range

switching

|

In

Fey

B/3

Cv

|

en

rane

en

et

el

lee

T

hihat

(With

RC-10

connected)

LSS

|

;

|

High

when

remote

control

unit

VR

is

ON

>

EO

|

;

|

Qs

Low

when

remote

control

unit

VR

is

OFF

|

aes

weer

’

+

j

|

=

jl

Adis

L

rity!

|

9

8

=

{

|

ty

|

:

L

byl

y

bo

:

™

|)

iwl

jo

|

1

8

o,

lz

ow

L

a

af

L.

iS)

ps

|

uP

=

;

:

|

a

|

Lod

'

¥

ces

———~<

CS

High

for

dual

band

LL!

4

t

os

Low

for

single

band

.

LY

-

a

ES

Tan

ES

Ic

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4

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we

|

{

L

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LC7534M

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E

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i

|

F

|

Remote

control

elect

VOL

|

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-¥4

i:

I!

won

wtifecsdc

suneemebenobsnalene

panera

cane

qufraie

baated

AF

i

|

i

POWER

.

Wy

16

Pop

it

19

AMP

ALS

opti

i

|

1

ai)

|

1c

2

TX-RX

(144

MHz)

unit

a=

4

|

———a|

X57-3400-XX

PA

i

8

T

TTT

H

t

AIM

-

IC1,2:

TC4053BF

t

gtectronic

VR

switching

Fig.

7

AF

Volume

Switching

Diagram

TM-731A/E

CIRCUIT

DESCRIPTION

¢

Muting

Circuit

There

are

three

types

of

audio

muting:

MU1

:

Mutes

the

main band

momentarily

during

memory

scan

etc.

And

during

transmission.

MU2

:

Mutes

the

subband

when

the

CTCSS

key

is

pressed.

MU3

:

Operates

when

the

MUTE

key

is

pressed

on

the

front

panel.

¢

Speaker

selection

In

the

TM-731A/E,

a

selection

between

the

separate

and

mix

modes

is

made

depending

upon

the

connection

between

the

speaker

output

and

the

external

speaker.

(Refer

to

Table

6-1.)

When

the

separate

mode

is

engaged,

an

attenuator

is

insert-

ed

for

level

adjustment.

(Refer

to

Figure

8-1.)

16

MAIN

AF

co

+

yo

t3

95

Mutes

audio

output

dur-

ing

momentary

memory

on

scan

during

transmission

en

sue

AF

Ic

,

AOM

3pin

3

Ql3

2

©

———----_—|-——0

Aos

ie)

&

Tt

_

|

&

SHIFT

£

+:

REGISTER

82°

om

MUTE

C3

Qs

MUI

Mu2

MUS

7

(e)

SUB

BAND

[Sus

BAND

MUTE

Active

2048

MUTE

/

High

/

Mutes

subband

Microprocessor

Operates

when

MUTE

wher

CTCSS

data

control

is

pressed

on

front

panel

Fig.

8

Mute

Circuit

p———_—«—Main

AF

signal

+

buzzer

+

t

Bc

oa

i

|

oo

R53

A

eSure

Sub

AF

signal

a

©

a

:

«

c3

.

TC4053BF

MAIN

output

to

1

of

IC4

*

only

in

separate

mode

CN4

o

MSS

L—_____»

Figure

8-1

Speaker

separate

circuit

°

When

the

speaker

jacks

are

connected

into

the

MAIN

termi-

nal,.the.

MSS

terminal

becomes.open.and

the

pins

10

and.11_

of

IC3

become

‘‘H’'

so

that

AF

signals

are

each

input

to

the

audio

amplifier

(IC4)

at

they

stand

separate.

While

when

the

speaker

jacks

are

not

connected

into

the

MAIN

terminal,

the

MSS

terminal

is

grounded,

the

pins

10

and

11

of

IC3

become

“1”

and

R53

is

shorted

for

level

adjustment

so

that

AF

sig-

nals

are

mixed

together

into

only

the

13

of

IC4.

MAIN/SUB

output

to

14

of

IC4

in

mix

mode

-

SUB

output

in

separate

mode

Connected

only

to

(Connected

to

both

Without

extemal

|

Connected

only

MAIN

"SUB.

MAIN

and

AF

speaker

to

MAIN

terminal

.

MAIN/SUB

;

terminal

.

signal

terminals

.

External

speaker

Main

internal

speaker

External

speaker

|

External

speaker

{connected

to

MAIN

terminal

External

speaker

Sub

Internal

speaker

internal:

speaker

|

External

speaker

connected

to

IMAIN/SUB

terminal

Mix

Separate

Mix

Separate

Table

6-1

Correspondence

in

connection

between

speaker

output

and

external

speaker

TM-731A/E

CIRCUIT

DESCRIPTION

Transmitter

Circuits

*

Modulation

Circuit

:

The

audio

signal

from

the

microphone

is

fed

to

three

opera-

tional

amplifiers

which

perform

preemphasis,

amplification,

and

limiting,

and

form

a

splatter

filter

that

removes

unwanted

high-

frequency

components.

The

modulation

circuit

directly

modulates

the

VCO

(Voltage

control

oscillator)

for

the

144

MHz

and

430

MHz

bands

by

us-

©

General

Except

for

the

microphone

amplifier

and

APC

{Automatic

Power

Control)

circuits,

the

transmitting

circuits

are

independent.

MIC

AMP

(X59-3610-

00)

ing

a

varicap.

(See

Fig.

9.)

ro

mc

ee

|

RIG

O

|

C4,

27P

ls

|

9

1I

cs

S78

|

s

Bs

R7?_

390K

0033

+

|

=

z

"

iC!

|

N

R5

C3

RG

|

&

i

=

RIO

RIS

PN

27?)

|

el]

560

933].

0

33K

.033

82K

ao

|

a

3

|

oe

y

8

|

x

9

-

ke

&

=

vi

S

x

ICHI/2)

+

N

°

|

=f

et

|

Ep

8

I

|

220K

|

5

|

y

yt

|

16v

O

|

O

m

,

€

4

=

gle

TO

.

j

r

“TTP

RBS

Qi:

28c4ai6ly)

ICl

|

NJM4558M

|

t——-

144

PLL

aS

||

ghee

wee

ne

eee

CHP

-

oo

Fig.

9

Modulation

©

|

gsomol

ig.

odulation

Circuit

|

430

MDI

aay

nue

TX-RX

UNIT

*

Preamplifier

Stage

Circuit

;

.

©

Power

Amplifier

Circuit

A

three-stage

linear

amplifier

is

used

in

both

the

144

MHz

and

The

drive

signal

is

fed

to

the

power

modules

and

amplified

to

430

MHz

bands.

Due

to

its

wideband

design,

this

linear

am-

the

required

levels.

It

then

passes

through

the

TX/RX

switching

plifier

provides

stable

drive

output

without

adjustment.

diode

and

a

filter

and

is

transmitted

via

the

antenna.

.

Rating

Item

Symbol

|

Tc

(°C)

|

Unit

Conditions

5

:

_

;

S-AV17

:

M57788M

Operating

voltage

Vee

25

i

V

16

°

17

Current

consumption

lec

25

A

14

Input

power

25

Ww

Zo

=Z_.=50

0

0.6

(Vcc12

13.8

V)

Output

power

Po

25

WwW

Zo=Z.=50

0

65

55

.

‘Operating

case

tem=

“To

(op)

|

.

oe

~

“pose

.

“362371607

menses

osensann

soar

ges

papain

perature

Storage

temperature

Tstg

ae

:

—40~

+110

-40~+110

Table

7

Maximum

Ratings

of

Power

Modules

*

APC

and

SWR

(Standing

Wave

Retio)

Protection

Circuits

The

APC

(automatic

transmit

output

control)

circuit

and

pro-

ching

at

the

CM

(Capacitance

Matching)

coupler,

detects

it,

tection

circuit

have

independent

detectors

in

both

bands.

The

and

feeds

the

result

to

the

hybrid

IC.

contro!

circuit

is

a

common

hybrid

IC.

The

hybrid

IC

controls

the

power

transistor

Q5

:

2SD1406

(Y)

The

APC

detects

the

output

from

the

power

module

and

feeds

in

the

drive

stage,

controls

the

drive

transistor

and

the

second

the

result

to

the

hybrid

IC.

The

SWR

protection

circuit

extracts

of

the

power

module,

and

thus

varies

the

transmitter

output.

a

portion

of

the

reflected

wave

generated

by

antenna

mismat-

TM-731A/E

CIRCUIT

DESCRIPTION

Power

amplifier

144

MHz

Final

Unit

PLL

Synthesizer

Fig.

12

is

a

block

diagram

of

the

PLL and

VCO

sections

of

the

144

MHz

and.430

MHz

circuits.

A

feature

of

the

PLL

system

in

the

TM-721A/E

is

that

there

are

independent

subunits

for

the

144

MHz

and

430

MHz

bands,

each

consisting

of

an

up-

per

VCO

section

and

a

lower

PLL

section.

Both

sections

are

enclosed

in

a

sturdy

case

that

shields

them

from

external

signals.

To

provide

6

kHz,

10

kHz,

12.5

kHz,

20

kHz,

and

25

kHz

steps,

the

12.8

MHz

frequency

of

the

reference

oscillator

in

both

the

144

MHz

and

430

MHz

bands

is

divided

by

2048

and

2056

according

to

the

step

count

to

yield

frequencies

of

6.25

kHz

and

5

kHz.

Each

VCO

oscillates

directly

at

the

tar-

get

frequency.

After

single-stage

amplification,

the

frequency

is

applied

to

a

pulse-swaliow

PLL

IC

which

divides

it,

performs

phase

comparison,

and

locks:

the

frequency.

The

PLL

system

for

the

144

MHz

band

locks

without

switching

between

TX

and

RX.

The

lock-up

time

of

the

PLL

is

shortened

by

using

10

of

the

PLL

IC

(M54959FP),

which

is

Low

in

TX,

to

turn

off

the

low-pass

filter

Q1

and

Q2

in

Fig.

13,

only

at

the

instant

when

the

set

is

switched

to

TX,

thus

shortening.

The

time

it

takes

the

transmitter

to lock.

The

PLL

system

for

the

430

MHz

band

locks

on

a

single

VCO,

with

band

switching

for

TX

and

RX

performed

inside

the

VCO.

TX-RX

(430)

Unit

(X57-3390-XX)

©

8T2

(Transmit

8V)

and

Uniock

Circuit

Dueing

receive,

0.7

V

desional

is

applied

to

the

base

of

O09

which

turns

Q9

on,

Q8

off,

and

Q11

off,

so

no

voltage

is

out-

put

at

the

collector

(8T2)

(TX

+8

V)

of

Q11.

When

the

PTT

(Push-to

Talk}

switch

is

depressed,

serial

data

is

sent

from

the

microprocessor

to

IC1

(the

phase-locked

loop)

causing

10

of

IC1

to

go

Low.

This

switches

Q9

off,

Q8

on,

and

Q11/on,

so

that

8

V

is

applied

to

8T2.

(In

transmission,

8

V

is

applied

to

8T2

from

8C.)

Ov

(8:0V)-

——

_

-

icuosomuiametens

eesiatecosisie

ss

=

*(OV)

Qu

t2SBINI9S

BT2

f

\—-4

ac

85

aee

Subunit,

IC1

10

(TR2)

‘

8.0V

(ov)

%(8.0V)

\

Subunit,

ov

iC1

14

(TR2)

epOTV)

*

When

uniocked

Fig.

11

8T2

(Transmit

8

V)

and

Transmit

Unlock

Circuits

CIRCUIT

DESCRIPTION

TM-731A/E

MDI

as

tend

Sel

——Me

eee

ee

eee

esl

r-----

_

X57-3390°XX_

ee

|

Ppa]

|=

X88

25680-0_

s|

|

it

tt

qt

PLL

LPF

F.CONT

MOD

purr

|

Id

ic

|

21,02,

03

|

DIO!,O102

|_|

DIOS

‘aon

t

4

|

!

|

[Msagsorp

[~|2scaszay{

y

|

|it33c

isvieE4

.

ry

1

|

1

ly

i

|

{

FLR/LT

SW

|

1

i

I

4

|

05,

06

I

4

it

Ly

ISV128

"

|

1

|

tt

|

430~

‘

|

439.995

MHz

(M,W)

|

t

I

|

438

~

449.995

MHz

(K)

(P)

l

399.175~

1

|

I

i

309.17

MHz

(MW)

H

|

t

(B/2)

J

416,400~

428.395

MHz

(K)

(P}

!

ee

SI

TITIIIIIIIT-

OUT!

Ll

Le

ee

a

nan

ee

~

gure

p>

~~

ee

He

TO

re

1

Ene

neeneeneeienieiee

|

potted}

PY

pu

LPF

y

!

F.CONT

RXVCO

BUFF

4

1

|

IC

|

Q1,2

94

1

|

DIO1,D1I02

1

-

>.

||

M54959FP

2Sc3324(8)}

|

fy

|

iTs38c

'

1b

ZN

sw

tt

{

I

Q5

|

1

|

DTCI44EK

1

[LJ

D103,0104

1]

t

|

ISV

166

DIS

|

AMP

|

MOD

1

|

DICI4EK

ISV268

|

Txvco

suff

If

|

=

I

|

j

7

ty

144~

147.995

Miz

(KM)

(P)

ia

A

LA

[145.995

Me

.

Muz

|

:

be

ie

X58

5860-0

Tx

SO

Size)

133.32

136.998

MEE

(MWh

l

K.

Le

—

MO(XS7-3610-00)

Fig.

12

PLL

and

VCO

Block

Diagram

fe

oa

P/N:

-Lock~

~——

-——

-

—

-

—

-

—

-

—

-

—

-—

-

-~Q—-

—-}

i]

X=

IN

@8)

osc

|}

—+{

478

piv.

F}

4

Ref.

freq.

divider

|

:

X-OUT

@)

oe

est

L

-

1

+4

Veo

FIN

2.

Modulus

VA

divider

Ref.

freq,

|

fR

PD

.

IN

prescalor

b

(binary

7

bit!

select

det.

t

VREF

:

(1/128,

1/129)

_

if

|

B)

PD

t

(/N

Programmable

divider

fin/

N

(Binary

10

bit)

'

|

$2

$10

r?

1

|

21

bit

data

latch

6

cee

sw

421

>

@)

sw2

s1

>|

21

bit

shift

register

|

@)

Vee

aPS

G

ol

21

puso

counter

|

Latch

signal

@®

GND

1

pluse

counter

RST

Fig.

13

M54959

Pulse

Swallow

Control

Circuit

TM-731A/E

CIRCUIT

DESCRIPTION

The

unlock

circuit

operates

only

in

the

transmitter

circuit.

A

description

of

the

430

MHz

unlock

circuit

follows.

Q10

is

the

PLL

unlock

switching

transistor.

Normally

the

base

of

Q10

is

Low

(0

V)

and

the

collector

of

Q10

is

High

(8

V).

When

the

PLL

unlocks

0.7

V

dc

is

applied

to

the

base

of

Q10,

Turning

Q10

on

forcing

the

collector

to

0

V

(Low).

This

swit-

ches

O8

off.

When

the

PLL

unlocks

(during

transmission),

the

collector

of

Q8

goes

to

8

V

(instead

of

the

normal

0

V)

and

Q11

turns

off.

Therefore

the

8T

switching

transistor

Q11

turns

off

and

the

transmit

bias

voltage

goes

dead.

This

prevents

trans-

mitter

output

when

the

PLL

is

unlocked.

©

8R

(Receive

8

V)

Stop

Circuit

In

receiving,

the

base

of

Q13

receives

an

5

V

dcsignal

that

turns

Q13

on

{so

the

collector

of

O13

goes

to

O

V).

O12

then

turns

on

and

provides

8

V

at

its

collector.

(In

receiving,

8

V

is

sup-

plied

from

8C

(Common

+8

V)

to

8R.)

During

transmit,

serial

data

from

the

microprocessor

is

pass-

ed

thru

shift

register

IC4.

The

output

from

IC4

at

11

goes

Low.

Q13

therefore

turns

off

(its

collector

voltage

going

to

8

V),

Q12

turns

off,

and

no

8R

output

is

provided

from

the

collector

of

Q12.,

The

PLL

1C

(M54959FP)

can

be

controlled

for

its

two

refer-

ence

division

ratios

and

single

comparison

division

ratio.

in

the

144

MHz

band,

the

relation

ship

between

Fvcot

and

the

division

ratios

is:

Fvcor.

=

(144—10.7)

=

{(n1x128)

+

Al}

x

Fosc

+

R

Fvco1

:

Output

frequency

of

144

MHz-band

VCO

ni

:

Value

to

which

binary

10-bit

programmable

counter

is

set

Al

:

Value

to

which

binary

7-bit

programmable

counter

is

set

Fosc

«°

Reference

oscillator

frequency,

12.8

MHz

R

':

Value

to

which

binary

14-bit

programmable

counter

is

set

R

=

2560

for

5kHz,

10

kHz,

20

kHz,

and

25

kHz

steps

R

=

2048

for

12.5

kHz

steps

ff

n1=208,

A1=36,

then

with

5

kHz,

10

kHz,

20

kHz,

or

25

kHz

steps:

Fvcoi

=

{(208

x

128)

+

36}

x

12800

+

2560

=

(26624

+

36)x5

=

133300

=

133.3

MHz

In

the

430

MHz

band

the

relation

between

Fvco2

(RX)

and

the

division

ratios

is:

Fyco2

=

(430

—

30.825)

=

{(n2

x

128)

+

A2}

x

Fosc

+R

The

pulse-swallow

PLL

circuit

is

contained

on

a

single

chip

and

consists

of

a

built-in

dual-modulus

(1/128

and

1/129)

prescaler.

The

switch

function

(pin

10)

of

the

PLL

IC

controls

the

8T1

|

(TX

+8

V

(430

MHz))

and

8T2

(TX

+8

V

(144

MHz))

lines.

“8c

al2

.

BR

Shift

register,

x

1C4

11

2

>

av

2

¥

(OV)

wo

Ko

=

co

ag

™

<<

ov

(8Vv)

Bc

C96

1

I6V

Fig.

14

8R

Stop

Circuit

Fvco2:Output

frequency

of

430

MHz-band

VCO

R

and

Fosc:

Same

step

frequencies

as

in

the

144

MHz

band

in

this

case

n2=623

and

A2=91,

so:

Fvco2

=

{

(623

x

128)

+

91}

X

12800

+

2560

=(79744491)x5

=

399175

=399.175

MHz

Kenwood TM-731A Manual de usuario

Manuales populares de Radio de otras marcas