Teac A-3340S - Page 29

OVERALL
FREQUENCY
RESPONSE
OOOO
IMPORTANT
To
avoid
saturation
of
the
tape
these
checks
should
be
made
at
least
20
dB
below
the
specified
input
level.
Any
bias
signal
HIGH
1,
2%
3:6
feeding
into
the
test
equipment
should
be
filtered
out
by
ad-
justing
the
external
bias
trap.
A
broad
band
VIVM
may
be
used
at
the
output
for
this
adjustment.
position, BIAS and EQ switches
Thread
the
unit
with
a
record
Test
Tape
(Scotch
203).
Set Tape SPEED selector to HIGH position.
Adjust
the
AF
oscillator
to
obtain
an
output
level
of
-23
dB
at
OUTPUT
jacks.
Apply
a
signal
swept
from
50
Hz
to
18
kHz
to
the
unit
while
recording
on
the
test
tape.
With
OUTPUT
switch
at
TAPE
po-
sition
monitor
the
output
at
the
Test
Set.
See fig. 7-9 for proper response limits.
.
Repeat
the
above
procedures
for
L
(3-3/4
ips),
using
a
signal
swept from 50 Hz to 15 kHz.
If
response
is
not
uniform
the
heads
should
be
checked
for
accumulated
dirt
or
tape
oxide.
If
heads
are
clean,
the
equalization
coils
L-301
and
L~-303
should
be
adjusted
(both
speeds).
NORMAL
position,
BIAS
and
EQ
switches
1,
2.
as
RESPONSE IN dB
Thread the unit with a record Test Tape (Scotch 150).
Repeat
the
overall
response
check
at
both
tape
speeds.
The
record
equalization
should
give
the
proper
frequency
response.
Lf
further
adjustment
is
required,
adjust
VC-502/504
for
best
response.
t i 7
eee ede ere A Se cme Ee LEE; EE ae
1_| a
50 100 500 1K ' 5K TOK I8K 20K 22K BOK
Seatch #166
aa Seatch #203
FREQUENCY IN He
Fig. 11-6 Frequency Response Limits
-Record-