Philips n 4308 service manual

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TAPE RECORDER

SERVICE INFORMATION FOR THE

pumps Stella
N4308 ' , ST9123A

For Service Manuals Conlad
MAURHRON TECHNICAL SERVICES
8 Cherry Tree Rd. Chinnot
Oxon OX9 4QY
Tel:- 01544-351694 Fax:- 01mm
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COMBINED ELECTRONIC SERVICES LIMITED
604 PUHLEY WAY WADDON CROYDON CH9 4BR

TELEPHONES :
Spare part orders: 0i-686 3B3l General service enquiries: OI-688 7722
After business hours: Recorded messages on body lines ' Telex 262308

NOVEMBER. I969 (Please quote CES 753 when ordering further copies) CES 153

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N4308 ST9IZ3A
C 0 N T E N T S
Page No.

A -- INTRODUCTION 1
B -~ SPECIFICATION 1
C ~ ACCESSORIES l
D -- OPERATION 1
E - DISMANTLING 2
F - MECHANICAL DESCRIPTION 4
O - MECHANICAL REPLACEMENTS 4
H - MECHANICAL ADJUSTMENTS 5
I - ELECI'RICAL ADJUSTMENTS AND

MEASUREMENTS 7
J - CLEANING AND LUBRICATION 11
K - SPARE PARTS LIST l3

A-INTRODUCTION

These models, utilizing an electrically similar chassis, are four-
track, two speed, mains-operated, tropicalizcd tape recorders,
employing ten transistors and three diodes. Recording facilities
include signal input mixing, loudspeaker or headphone monitoring
and a meter-type recording level indicator. Provision is made for
using the recorder as a microphone, radio, or pick-up amplifier
and, when used in conjunction with the Stereo pro-amplifier
EL3787A/00A etc., Stereo playback/Multiplay/Duoplay is also
possible.

B-SPECIFICATION
Recording/playback system Monophonic, 4-track, left to right
Tape speeds 3% and 1; i.p.s.
Maximum reel diameter 7 in.

Over 12 hrs. at I; i,p.s. (17 hrs.
with DtP. tape)

Fast wind/rewind time 3 mins. for 1,200 ft. of tape
Modulation level indicator Moving coil meter type

Microphone Moving coil type N8301

Frequency response 3% i.p.s.: 60-14,000HZ

I} i.p.s.: 80-8,000Hz

Maximum playing time

Wow and flutter $0.25 7,, at 3} i.p.s.
Signal to noise ratio Better than 45dB
Semi-conductors ' Tl BC109B/ECI4SB

T2 BC 109B/BC148B
T3 BCIDQB/BCMSB
T4 BCIOS/BCMSA
T5 BClOS/BC 148A
T6 AC1 87/01

T7 ADI62

T8 AD161

T9 AC125

T10 BC108A

X1, X2 BY126/0F160
X3 OA95

Input/output sockets
Inputs: Sktl-Radio Pins 1/4 and 2-2mV into ZOKQ
(diode) (with EL3768/03 connecting lad--
lSOmV via 1.5MQ)
Pick-up Pins 3 or 5 and 2-100mV into 1M0
SktZ-Microphone Pins 1/4 and 2-0.2mV into Zkfl

Outputs: Sktl-Line (diode) Pins 3, 5 and 2-750mV across 20k!)
SktJ-Stereo For use with EL3787A/00A Stereo
pre-amplifier
Skt4-Ext. L.S. Impedance 4 or 89, 4 watts
SktS-Headphones Pins 4 and 1/2
Power output 4 watts
Loudspeaker 6 in. x4 in. elliptical, SQ
Mains voltage 110, 127, 200-250 volts a.c. sottz
(adaptable to 60Hz)
Mains consumption 40 watts approx.
Weight 17% lb. (N4308) 17% lb. (ST9123A)
Dimensions N4308-16i in. x 11:} in. x 5% in.
ST9123A-16 in. x 111} in. x 6} in.

C-ACCFSSORIFS

Recording lead with S-pin DIN plug at each end . . EL3768/i4
Connection box/extension laid for two microphones N6206
Slide synchroniser . . .. . . .. . . EL199S
Stereo pro-amplifier EL3787A/00A
Continuous tape loop . . EL1907/52 or CEIO
Tape splicing kit . . . . . . . . . . SKIO
D-OPERATION
1. Record

Depress on/ofi switch 205, and select the required speed and
track. The level of recording may be controlled as follows. Depress
Record key 207 and adjust the appropriate controls so that the
modulation level indicator pointer almost reaches the red section
of the scale during the loudest passages. To commence recording,
hold the Record key fully depressed, then depress Play key 210.
On completion of recording, depress Stop bar 212. When recording
from a source other than a microphone, it may be necessary to
include some form of attenuation in the connection to avoid over-
loading the input stages. The lead type EL3768/14 should be used
whenever the input source employs a. S-pin DIN diode output
socket. On all other occasions, the input signal should he applied
to pin 3 or 5 of input socket Sktl, or the lead type EL3768/03
supplied with the recorder should be used. This lead incorporates
a series resistor, 1.5MQ, in the red conductor, but under certain
conditions, depending on the amplitude of the input signal, the
value of this resistor may be altered to obtain satisfactory record-
ings. The connections of this lead are: Red-recording input;
White-line output; Black-common earth (screening), see Fig. l.

Fig. l Radio/Plek-up Connecting Lead

2. Monitoring

Monitoring during recording can he carried out using the internal
loudspeaker or headphones, with the volume and tone controls
operative. Acoustic feedback can be avoided by moving the micro-
phone further away from the recorder or by reducing the volume.

3. Playback

Select the required track operation and depress Play key 210.
The volume and tone controls can be adjusted as necessary. To
terminate Playback depress Stop bar 212.

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