Dual C 812 Serviceanleitung Seite 17

12. Aufnahme/Wiedergabekopf, Löschkopf
Bei Austausch des Aufnahme- /Wiedergabekopfes 103 ist folgende
Vorjustierung zu beachten.
Den Aufnahme/Wiedergabekopf 103 mit Blattfeder auf den Kopf-
träger aufsetzen, dann mittels den Buchsen und den Zylinder-
schrauben Z so befestigen, daß die Bandführung B mit den Band-
führungen des Kopfträgers B 1 und des Löschkopfes B 2 fluchten
(Fig. 6). Das endgültige Eintaumeln ist wie im Elektrischen Ab-
gleich beschrieben vorzunehmen.
13. Reinigung / Schmierung
Reinigung sollte bei jeder Reparatur erfolgen.
Für eine einwandfreie Funktion des Gerätes müssen der Aufnahme-
Wiedergabekopf 103, der Löschkopf 102, die Andruckrolle 128, die
Tonwelle, stets einwandfrei sauber sein. Zum Reinigen dieser Teile
wird vorzugsweise ein mit Reinalkohol getränkter Leinenlappen
oder ein Wattestäbchen verwendet. Auf keinen Fall dürfen metallische
Gegenstände verwendet werden. Auch ist das Berühren der Kopf-
spiegel mit ungeschützten Fingern unbedingt zu vermeiden.
Das Gerät wird im Werk an allen Lager- und Gleitstellen ausreichend
geschmiert. Ein Ergänzen der Öle und Fette ist bei normalem Ge-
brauch erst nach ein paar Jahren erforderlich, da die wichtigsten
Lagerstellen mit ölspeicherbuchsen ausgerüstet sind. Die Motorlager
sind als Longlife-ölspeicherbuchsen ausgelegt und sind daher nicht
zu schmieren.
Mechanical section
General information
The item numbers listed refer to the lists of replacement parts and
o 'Ploded
diagrams below.
1. Removing the housing plate 1 and the baseplate
Remove the four machine screws 2 and the four washers 3.
Withdraw the housing plate 1 from behind.
In order to remove the baseplate, the four machine screws 44 on the
underside of the unit should be loosened and both the supporting
feet 41 and the three sheet metal screws must be removed.
2. Removing the fascia 18
Remove the housing plate 1 as described above.
Withdraw the rotary turn knobs 31 and 32, the four push keys 21
and the rotary turn knob 20.
The three countersunk head screws 19 on the upper and lower fascia
should be removed.
The fascia 18 may now be ta ken off.
3. al Removing the cassette retaining biete 117
When repairing the mechanical section, it is advisable to remove the
cassette retaining plate 117 complete with both stop buttons 116.
To do this, proceed in the proper fashion as follows: Press the con-
necting spindle 12 into the bearing sprindle 10 and remove it. Pivot
the protective head cover 118 upwards. With theaid of a screwdriver,
extract both retaining lugs L on the cassette retaining plate 117. •
Carefully' withdraw the cassette retaining plate 117 from the unit
and remove the bulb 114 together with its rubber socket (Fig. 11.
b) Disengaging the contactor on the cassette retaining plate 123
In order to check the playback or fast wind/rewind function without
inserting a cassette, the contactor F of the cassette grip 123 must be
disengaged as follows:
Operating the playback key or the fast wind/rewind key, the contac-
tor F must be disengaged from the left cassette grip 123, thereby
allowing the key to click into position.
4. Motor
a) Replacement
In order to replace the motor 154, the motor belt and the flat
belt should be firstly removed from the drive pulley 141. Rotate
the motor in a counterclockwise direction -bayonet-typesocket
- and remove the motor 154. Now solder off the connection
leads from the printed circuit board I Fig. 2).
Loosen the grub screw and remove the drive pulley 141. Screw
off the retaining plate of the motor 154 and fix it to the new
motor.
Place the drive pulley 141 onto the spindle of the new motor
154. Set the clearance gap between drive pulley 141 and retaining
plate at approximately 0.3 mm, then tighten the grub screw.
Solder the connection leads to the printed circuit board (red = plus).
Insert the motor into the unit and, by rotating it in a clockwise
direclion - bayonet-type socket - lock it in position.
Replace the flat belt and motor belt onto the drive pulley 141.
b) Motor speed - tape speed
Test assembly as described below under 6. "Speed accuracy."
The tape speed may be adjusted by means of an insulated
screwdriver on the reverse side of the motor.
The speed is correctly adjusted if the measured result is between
- 1 and +0.5 % deviation.
5. Drive belts
In order to replace defective drive belts - belt arrangement dia-
gram fig. 3-, proceed as follows:
The motor belt A may be removed or replaced with no difficulty.
Remove the three machine screws 183. Ta ke off the lower plate 155.
The flat belt Et and the counter belt C may now be replaced. With-
draw the flywheel 144 from the bearing bush (Fig. 41.
Important:
The polyethylene washer 174 on the from side of the unit will fall
out.
The counter belt C 2 and the take-up belt D may now be replaced.
When the belts have been properly replaced, replace the polyethy-
lene washer 174 onto the spindle (capstan) of the flywheel 144.
Furthermore, it is advisable to press the fast forward or rewind key
and to clean the capstan and the drive belt with a cloth soaked in
methylated spirit.
6. Speed accuracy
Measure qith a Wow meter (e.g. Woelke ME 101 or ME 104 or Franc
EMT 420 A) and Wow test cassette 3150.
Setting the test instrument:
0.3 % measurement range, weighted.
I mportant: In order to avoid incorrect caused by jamming tape travel,
it is recommended to operate the forward and rewind but-
ton with the test cassette inserted.
Typivsl measured values (playback) of the Dual cassette deck.
- ± 0.08 - 0.12 %
Individual higher deflections should not weighted since
they are the result of bad tape-head contact caused be
detrition, dust or felt perfides.
If necessary, check the following points:
a) Clean pinc roller and capstan
b) Check pinch roller for freedom of movement
c) The take-up torque, which is adjusted at the coupling, should
be 55 ± 1 mN m 155 ± 10 pcm) . Slightly fluctuating values have
no effect on the Ipeed accuracy. At the same time, the torque on
the non-driven side should be 2 - 6 pcm. A higher or varying
value suggests that the bearing of the left winding gear ist defective.
d) Replacr the flat belt
e) Replace flywheel
7. Pressure lever 0.1 mN m = 1 pcm
The pressure lever 128 and the V spring 127 may be removed after
the lock washer 167 has been loosened. Reassembly involves the re-
verse procedure. However, please ensure that the V spring 127 is
correctly repositioned. With the pause button disengaged (device
switched to play), the pinch roller should be pressed against the cap-
stan by the V spring 127 with a force of 400 p ± i gs p. I f necessary,
this should be alteredby pretensioning of the V spring 127.
Correct functioning of the pressure lever 128, may also be checked
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