Teac A-7300RX - Page 22

10-17
BIAS
ADJUSTMENT
Be
sure
the
Bias
Trap
has
been
adjusted
per
section
8-14
and
8-15,
before
proceeding.
Tape
SPEED
SW
.
.
.
LOW
(7-1/2
ips)
BIAS
and
EQSW
.....---
++:
1
14.
Apply
7
kHz
signal
at
~18
dB
(97
mV)
to
the
LINE
IN
jacks.
15.
While
recording
on
the
YTT-8013
Test
Tape,
adjust
capacitor
VC-551/552
(on
BIAS
OSC
UNIT)
for
peak
reading
on
the
VI'VM,
then
turn
the
capacitor
clockwise
until
a
decrease
of
2.7
dB
from
the
peak
is
obtained.
——>
BIAS
T-623
Fig. 10-12 Bias Limits Chart
10-18
RECORD
LEVEL
SET
Tape
SPEED
SW....--
HIGH
(15
ips)
BIAS
and
EQSW
.......-----
1
16.
Apply
a
400
Hz
signal
at
—8
dB
(308
mV)
to
the
LINE
IN
jacks.
Be
sure
the
LINE
and
Output
controls
are
still
at
their
previously
set
positions.
17. Begin recording.
18,
Adjust
VR-709/710
(on
TRIMMER
RESISTORS
UNIT)
for
~8
dB
(308
mV)
at
OUTPUT
jacks.
10-19
FREQUENCY
RESPONSE
—OVERALL—
NOTE:
Any
Bias
signals
feeding
into
the
Test
equipment
should
be
filtered
out
by
using
an
external
Bias
Trap.
— RECORD BIAS and EQ SW at position 1 —
Tape SPEEDSW..... HIGH (15 ips)
19. Apply signal swept from 30 Hz to 28 kHz, ~8 dB (308
mV) to the LINE IN jacks and record on a blank TEAC
YTT-8013 Test Tape. _
20. During recording, monitor the Tape signal and adjust
equalization VR-503/504 (on REC AMPL. UNIT) for
readings within the Response Limits chart. See Fig.
10-13.
21. Apply the same signal swept at —28 dB (30.8 mV) level
and while monitoring the off-the-Tape signal check also
for readings within the Response Limits chart. See Fig.
10-13.
Tape SPEED SW... LOW (7-1/2 ips)
22. Apply signal swept from 40 Hz to 24 kHz, —28 dB (30.8
mV).
23. During recording, monitor the Tape signal and adjust
eugalization VR-501/502 (on REC AMPL. UNIT) for
readings within the Response Limits chart. See Fig.
10-13.
HIGH (15ips),----for Input Level -8dB
RESPONSE IN dB
50 100 500 1K
FREQUENCY IN He
(7-1/2ips)
——
Input Level
panels
RESPONSE IN 6B
Fig. 10-13 Frequency Response —OVERALL — 1
z3