Record Mode (Video)

The current input applied on RECIN Pin is amplified

througha transconductanceamplifier. Special care

has been taken to speed up commutation from

Playback to Record and from Record to Playback,

avoiding spikes through the loads (the rotary trans-

formers). The recording current level in LP mode is

0.9 time the value of SP one.

Playback Mode (FM HIFI)

Signals applied on H1FM and H2FM input Pins will

AC short-circuited to ground by CCOM1. The input

signal can be selected through SWFMH input and

the correspondingoutput signal will be available on

Pin FMPB.

Record Mode (HIFI)

The current input applied on FMRIN Pin is amplified

through an Automatic Gain Control amplifier. The

resistance connected to TRIV Pin. Special care has

been taken to speedup commutation fromPlayback

to Record and from Record to Playback, avoiding

spikes through the loads (the rotary transformers).

1

2

3

4

5

6

7

8

9

10

19

60dB

60dB

De tector

Re cord

Amplifica tor

STV5728

H1SP

H2SP

S P HEADS

CCOM

SWR

SWH

SWM

V

CC

YREC

CREC

CPB

YPB

TRIV (ATR)

+5V

Rrcy

Rrcc

REC

PB

H2LP

H1LP

H1SP

H2SP

H2LP

H1LP

LP HEADS

60dB

60dB

21

Playba ck

AGC

22

23

24

20

25

26

27

28

CAGC

ENV

Enve lope Comp

8.2k

Ω

22k

Ω

11

12

13

14

CCOM2

H1FM

H2FM

70dB

70dB

HIFI HEADS

Re cord Re ference

Current (FM)

R

ADJ

FMREC

Rfmin

18

FMPB

17

SWFMH

16

V

CCFM

15

+5V

Re cord AGC

H1FM

OFF

H2FM

ON

PB

REC MUTE

BLOCK DIAGRAM

FUNCTIONAL DESCRIPTION

STV5728

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