Teac A-4070G - Page 23

RECORD °SERFORMANCE
Before making any adjustments on the record amplifier, be sure that
all tests in the HEAD ALIGNMENT, PLAYBACK and MONITOR PERFORMANCE
sections
have
been
accomplished
and
that
all
adjustments
are
correct.
Optimum recording performance(bias levels, recording levels and fre-
quency response) is dependent upon tape characteristics. The TEAC
A-~4070G is factory set for Scotch type 203 or 150 tape. Service data
is based upon the use of Scotch 203 or equivalent tape
REC LEVEL SET HIGH
Q2i0
aut
O22
FORWARD
REVERSE
Bae
TRAE
VR103/203
VRID4/204
CHECK
POINT
Lia #268 RECORD HEAD
| pre $5
-
°
@Lioav203
Bh
REC LEVEL 10}
NORMAL lot
VR108/208 tol
1 L23
REC METER LEVEL SET 9"? | 305
VRIOT/207 i
MONITOR.
TAPE
VRI06/206
NOTE
+ Simplified diagram shown in the RIGIT
cha
Fig. 7-5 Simplified Diagram -Record-
BIAS
TRAP
ADJUSTMENT
———————___________
NOTE
The bias trap tank circuit keeps the bias signal
from
reaching
the
record
and
monitor
amplifier
and
under
normal
no
signal
conditions,
voltage
should
not be present at the OUTPUT jack.
1.
Thread
a
blank
tape
or
block
tension
arms
in
on
position.
Place the RECORD BIAS switch to HIGH position.
3.
Connect
a
VIVM
or
oscilloscope
to
junction
of
C-146/L-102,
C-246/L-202.
No
4. Adjust L-102, L-202 for a minimum reading.
5.
Adjust
L-101,
L-201
for
a
minimum
reading
at
OUTPUT
jacks.
BIAS OSC
Ll02 /202
Ciaer2ae] REC HEAD
Q1147214 <.
CHECK POINT
M-0283
Fig. 7-6 Bias Trap Check Point and Bias Leakage