Revox A77 Service Manual

Mobil DTE extra heavy
Fig. 4.5-26
D
A
ATTENTION
Capstan Motor with Sleeve Bearings
Modification effective from
serial Nr. S 60483
G 78003
see section 8.6./page 35
4.5. Capstan Motor ( with Ball Bearing) Fig. 4.5.-26
( Control circuitry see 5.10 & 6.2.1
The capstan axis goes completely through the motor. It
is held by a sintered bronze bearing ( D ) and below by a
ball bearing. Both bearings are lubricated for their life and
should normally require no service. Capstan axis and ball
bearing can be exchanged very easily. A defective sintered
bearing is to be sent to the nearest factory representative.
I Disassembly see para 3.7. )
4.5.1. Removal of Capstan Axis, Ball Bearings
The capstan motor need not be removed to get axis and
bearing out.
— Unfasten securing clip A. Lower capstan rotor.
— The axis can be taken out through the top if the tape
guide between playback head and capstan axis has been
screwed off I don't disturb guide setting 1.
— If the retaining ring B is removed, the capstan axis can
be lowered with bearing C.
Bearing C is a special tight tolerance part and shall be
exchanged only with an original bearing.
Special care must be taken with handling the capstan
axis and bearings to avoid damage or entry of dust into
the precision parts I run- out better than 1/1000 mm
40 micro - inch ! ).
Instructions for installation of the new no- turn device A
in conjunction with old rotors are given on page PL 9 of
the parts list.
15

Revox A77 Specifications

General

Wow and Flutter	0.08% (7 1⁄2 ips)
Frequency Response	30Hz to 20kHz (7 1⁄2 ips)
Signal to Noise Ratio	60dB
Type	Reel-to-Reel Tape Deck
Track System	4-track, 2-channel stereo/monaural
Reel Size	Up to 10.5 inch reel
Motor	2 x reel, 1 x capstan
Inputs	Mic, Line
Outputs	Line
Tape Speed	3 3⁄4 and 7 1⁄2 ips