Harman Kardon CD491 - Controls and Functions - Part 1; POWER SWITCH (POWER); DOLBY NR SYSTEM SELECTOR (DOLBY BC NR); TAPE SELECTORS (BIAS;EQUALIZATION)

ALIGNMENT PROCEDURES (REFER TO PAGES 29 AND 30)
= ELECTRICAL ADJUSTMENT
1. Before adjustment 3. TEST TAPE
( ©@ After the power switch is pushed on, wait for 10 © Azimuth adjustment ............. MTT-114
minutes before measuring to be sure of the most © Tape speed adjustment . . MTT-111 or MTT-111D Dolby NR off
stable operation. © Playback amp. level adjustment ............. MPX Filter off
®@
Since
head
magnetization,
dust
accumulations,
etc.
ee
eee
eee
eee
MTT-150
or
TCC-130
Tape
Monitor
source
are
likely
to
introduce
errors
in
the
various
charac-
@
Playback
frequency
characteristic
confirmation
Bias
Fine
Trim
center
teristics, it is very important that the heads are TCC-162C and TCC-262C Timer off
Properly demagnetized and cleaned before © Auto search adjustment . . MTT-150 Output Level
commencing any adjustment, particularly frequen- © Auto search confirmation......... MTT-250B Oren =
‘ cy response and head azimuth adjustment. Reference tapes Mic. Level off
% LN.... oe XL Rec. Level max
5
2.
INSTRUMENTS
REQUIRED
CrO2
«+
AC512
Master
Fader
max
© Low frequency oscillator Metal ........ AC-711
@ AC VTVM or dual channel AC VTVM Note:
®@
Oscilloscope
C-90
differs
with
C-60
in
the
thickness
and
bias
is
© Wow/flutter meter unequal, so adjust with the tape whose bias is of
© Frequency counter specified value.
( Mi EES
VTVM
TP501
or
|
Azimuth
;
Refer
to
“Azimuth
adjustment”
eds
Test
tape
(MTT-114)_|
PB
TP502
screw
Maximum
sutpat
on
page
12.
Frequency counter F
i P8501 or VR built +30
7 Tape speed Test tape (MTT-111 PB ee VE allt kHz *30 Hz
" viva
Playback
amp.
7P501
vrio1
Test tape(MTT-150 | PB 580mV
level ert tape (mt TP502 VR102
:
Peacace
frequency,
YINM
Confirm
that
frequency
hi :
C
Poeteaet
td
See
Bee
CG
eRe.
||
ag
LINE
OUTPUT
response
is
within
the
C
range
in
Fig.
a.
i
vive
Set
the
auto
search
mode.
Auto
search
Test
tape
(MTT-150)
|
PE
TP761
A761
tomy
Tape
selector
is
CrO2
position.
‘Auto
search
;
Refer
to
“Auto
search
operation
ot
seh.
Test
tape
(MTT-2508)
confirmation”
on
page
9.
naar Tape selector is metal position.
eee: TP203 res) Set the bias fine trim to hi cut
Step
up
trans.
vtvm
proce
te
Maximum
output
position.
TP204 rd Set VR256 and VR257 all the way
to counterclockwise.
Tape selector is metal postion.
;
et
the
bias
fine
trim
to
hi
cut
Bias
trap
vTvM
Gee
aba
tae
Minimum
output
position.
Set VR256 and VR267 all the way
to counterclockwise.
7P203 VR287 Tape selector is metal position.
TP204 VR256 omy. < j ee
Bias
level
REC.
76203
VR255
;
Teecaesneail
vive
aes
Teas
yaaa
22mV
Tape
selector
is
CrO2
position.
pice veaes 13mVv Tape selector is LN position.
Biles
Trequency
Frequency
counter
Bae
1P251
105kHz
+
SkHz
Tape
selector
is
metal
position.
Apply 400Hz signal to LINE INPUT. Set REC
Record
level
vtvm
REC/PB
TP501
vR201
P
an,
;
LEVEL
knob
so
that
TPS61
and
TPS62
voltage
s80mV
Tape
selector
is
CrO2
position.
(Pre-adjustment) Blank tape (AC-512) EME E knob so thet Teee | ond TP502 vR202
Par Apply 27kHz signal to LINE INPUT. Set REC
Peaking
coil
REC-
7P201
L201
‘
Short
the
TP251
and
TP26
9 v 5s
(Pre-adjustment)
Tea
PAUSE
HOSOI
eee
ee
eae
ag
voltae
7P202
L202
Maximum
output
Tape
selector
is
metal
position.
VA257 So that the record/playback
L201 frequency response is flat , a
LINE OUTPUT |—jaoee lat least within whe faivoe Tape selector is metal position.
(
Ne
in
Fig.
b.)
vtvM Apply 400H2 signal to LINE INPUT. Set REC
pecata/Ptaybork Blank tapes RECRE LEVEL knob so that TP661 and TPS62 voltage zoe So that the record/playback
metal
AC-711
is
680mV
—25dB
in
REC-PAUSE
mode.
LINE
OUTPUT
frequency
response
#3
Tr
T
lector
i
ition.
frequency CrO2 AC-512 Then adjust with a 20Hz to 30kHz sweep VR254 {at least within the range ae Solero. C02 Pesren
characteristic
rote
cate
seals
L202
in
Fig.
b.)
yess So that the record/playback
R253 frequency response is flat i ts
\ LINE OUTPUT | Vroes (reer Cathie ahs cos Tape selector is LN position.
in Fig. b.)