Teac A-4070G - General Notice

7 MEASUREMENT AND ADJUSTMENT
—ELECTRICAL—
GENERAL NOTICE
Before performing maintenance on this
unit, thoroughly clean and demagnetize
the entire tape path.
It is important that the unit be set
to the proper voltage and frequency
for your locality.
TEAC specified standard test tapes and
test equipment must be used when per-
forming maintenance to insure reliable
results.
Procedures for checks and adjustments,
unless otherwise indicated, are for
the left channel at a tape speed of
7~1/2ips. The same procedures are to
be applied to the right channel and
again for both channels at 3-3/4ips,
and both directions,
All controls mentioned in this book will
be printed in bold letters and will be
exactly as they appear on the unit.
Double designated symbol numbers refer
to left channel/right channel.
T HD : Third Harmonic Distortion.
Fig. 7-1
PLAYBACK PERFORMANCE ADJUSTMENTS
CH PB LEVEL PB METER LEVEL
“@REVERSE | FORWARD >
L VR102 VRLOL VR1O6
R | VR202 VR201 VR206
BIAS ADJUSTMENTS
Adjustment Locations
CH | BIAS ADJUSTMENTS | REC BIAS TRAP |
| HIGH BIAS NORMAL BIAS
~@ REVERSE FORWARD Be ~@ REVERSE FORWARD
[u VC1O3 ve1OL ve1o4 | vc102 | _t102 |
[R vC203 ve201 ve204__ | _vc202 | t2z02 |.
RECORD PERFORMANCE ADJUSTMENTS
cH REC LEVEL | Rec £Q | REC METER LEVEL
HIGH POSITION NORMAL POSITION _|
s@reverse | FORWARD D> | REVERSE | FORWARD
VR104 vrio3 | ----- VRLO8 L103 vR107
VR204 R203 — vr2os | 1203 vR207