Bedienungsanleitung Marantz Model 2270 (Seite 15 von 24) (Englisch)

571034

Zoom out

Zoom in

Vorherige Seite

1/24

Nächste Seite

FRONT

END

antenna

signals are applied

through

a balun

transformer

and

the

antenna

attenuator

switch to

the

antenna

coil which drives a field-effect transis-

tor

RF amplifier. When

the

ATTENUATOR

push-

switch is placed in

the

"OUT"

position,

the

attenu-

ator

circuit

cut

off

and FM signals are directly

fed

the

antenna

coil. With

ATTENUATOR

switch placed in

the

"IN"

position,

the

signals are

attenuated

about

20dB by

the

attenuator circuit,

then

fed

the

antenna

coil.

The

amplified signals

from

the

RF ampl ifier are fed

through

the

triple-

tuned

RF filter

circuit

the

FET

Mixer stage,

which also receives

the

signal generated by

the

lo-

cal oscillator. This mixer converts

the

carrier frequ-

ency to

the

10.7 MHz

intermediate

frequency. Care-

ful

attention

its thermal and electrical characte-

ristics has minimized drift,

thus

obviating

the

neces-

sity for AFC.

The

10.7

IVI

converted

signal is

then

fed

a phaselinear ceramic I F filter, followed by

an IC limiter. It is

then,

turn,

processed

through

an FM

discriminator

The

output

the

FM dis-

criminator

is fed

composite

signal amplifier

which

then

drives

the

demodulator.

FM IF AMPLIFIER

The

IF amplifier consists of 8 ceramic filters and 7

stages

I F amplifiers including limiter stages.

The

characteristics

these

ceramic filters

are

ideal in

that

the

200KHz

passband

and

phase linearity as-

sures

the

elimination

major

source

high fre-

quency

distortion

and

loss

stereo

separation.

The

sharp

cut-off

slopes improve selectivity,

permitting

reception

closely spaced channels.

The

Model

2270

utilizes symmetrical

diode

limiter cir-

cuits

cons

isting

high

performance

Gold Bond

diodes and IC limiter amplifier with a very small

dynamic

aperture.

Thus, undesirable

Amplitude

Modulation is removed from

the

I F signal within

the

limiter

and

good

capture

ratio is also assured.

The

amplified

and

symmetrically limited FM sig-

nalsarefed

the

super-linear

discriminator

circuit

The

detected

audio signals are,

then,

distr

ibuted

the

QUADRADIAL jack,

MPXDecordercircuit

and

Noise Amplifier.

MULTIPATH INDICATOR

The

Multipath Indicator

circuit

is provided

aid

you

find

the

optimum

antenna

direction

for

desired

station.

Undesirable

Amplitude

Modulation

resulting

from

multipath

reception is

detected

and

displayed on

the

multipath

meter

when

the

MUL-

TIPATH pushswitch is held

"in"

. By

orientating

the

antenna

for

minimum

meter

deflection,

minimum

multipath

condition

obtained.

The

audible

signals

detected

are also fed

the

Tone

Amplifier

through

the

MULTIPATH switch, balance and

volume

con-

trol and

the

istorted

sound

due

the

undesirable

Amplitude

Modulation or

the

buzz-sound which are

proportional

the

MULTIPATH

meter

deflection,

can be heard

through

the

loudspeakers.

STEREO

DEMODULATOR

The

composite

aud

io signal from

the

composite

signal amplifier is fed

into

the

multiplex

stereo

demodulator

circuit

consisting

11 transistors

and

6 diodes.

The

19KHz

pilot

signal

contained

the

composite

audio signal is

doubled

into

38KHz

after

two

-stage amplification and

then

the

38KHz

signal is

further

amplified to

the

level

necessary to dr ive

the

diode

switching circuit.

The

composite

audio

signal is

decoded

into

the

right

and left channels by

the

38KHz

switching signal

the

diode

matrix

circuit.

The

right and left

channel audio signals are processed in

the

crosstalk

cancelling

circuit

which utilizes

complementary

configuration

with

NPN and PNP transistors.

The

audio signals are

then

fed

into

the

selector switch

and

the

RECORD jacks

from

the

low-pass filters

for filtering undesired 19-and

38KHz

components

and

emitter

followers

for

low impedance

output

The

stereo

demodulator

circuit

has been designed

with

the

de-emphasis

network

to provide flat

frequency

response up

15KHz

One

hundred

percent

air-tight coils

and

filters are

incorporated

the

stereo

demodulator

circuit

for

improved

stability and reliability with good stereo separation

and frequency response.

The

multiplex stereo

demodulator

circuit

has

been provided with an

automat

stereo/monaural

switching circuit.

The

circuit

checks

the

input

signal intensity and activates

the

stereo

demo-

dulator

circuit

and

the

stereo

indicator

lamp

automatically

only

when

the

input

signal is power-

ful enough

provide good

quality

stereo

recep-

tion

. When

the

input

signal strength is below

the

threshold

level,

the

stereo

broadcast

is processed

as monaural signal and improved signal-to -noise

ratio is

obtained

this

mode

operation

MUTING

CIRCUIT

the

absence

an FM carrier, all FM receivers

produce

a peculiar noise.

The

muting

circuit

elimi-

nates

this

no ise, providing

you

with noise-free

tun

ing

from

station

. A

muting

circuit, con-

sisting

all

semi-conductor

switching

circuit

inclu-

ding

two

EFTs, has

been

incorporated

the

Model

2270.

The

muting

circuit

perfectly

mutes

out

all

the

interstation

noise

and

also

completely

mutes

out

the

side slope

spurious

response of

the

unit

The

circuit

has been designed

minimize annoying

Missbrauch melden von Frage und/oder Antwort

Libble nimmt den Missbrauch seiner Dienste sehr ernst. Wir setzen uns dafür ein, derartige Missbrauchsfälle gemäß den Gesetzen Ihres Heimatlandes zu behandeln. Wenn Sie eine Meldung übermitteln, überprüfen wir Ihre Informationen und ergreifen entsprechende Maßnahmen. Wir melden uns nur dann wieder bei Ihnen, wenn wir weitere Einzelheiten wissen müssen oder weitere Informationen für Sie haben.

Marantz Model 2270 Seite 15

Brauchen Sie Hilfe? Stellen Sie Ihre Frage.

Missbrauch melden von Frage und/oder Antwort

Art des Missbrauchs:

Forenregeln

Neu registrieren

Das Handbuch wird per E-Mail gesendet. Überprüfen Sie ihre E-Mail.

Ihre Frage wurde zu diesem Forum hinzugefügt

Info