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DR-E34BK
DR-E34LBK
1-28
(No.
(3) Electrical Circuit Adjustments
Make the following adjustments after adjusting the head azimuth.
In principle, the adjustments should be made in the following sequence.
Set the NR switch to OFF and the BEAT CUT switch to "1".
Adjustments marked with an asterisk (*) should always be made after the head is replaced.
Motor speed
1. Playback VTT-712 with the deck
Semi-fixed
Connect a wow & flutter meter with
set to TAPE and an electronic
resistor of
counter connected to the SPK OUT
i
terminal.
. Normal speed Adjustment
1) Mechanism A adj.: Play back
R255
3,000 Hz
deck A and adjust the semi-
fixed resistor R255 on the
motor drive PC Board by
turning it so that the reading
of meter is 3,000 Hz.
Mechanism B adj.: Play back
R265
deck B and adjust the semi-
fixed resistor R265 by turning it
so that the reading of meter is
3,000 Hz.
. Double-speed adjustment
1) Mechanism A adj.: Play back
R256
6,000Hz
deck A and adjust the semi-
fixed resistor R256 by turning it
so that the reading of meter is
6,000 Hz.
Mechanism B adj.: Play back
R266
deck B and adjust the semi-
fixed resistor R266 by turning it
so that the reading of meter si
6,000 Hz.
a built-in electronic counter to the
Playback VTT-724 (1 kHz) and adjust
.
INPUT.
so that the output among W022(L),
W021(E) of TPO01
and W020(R),
105 kHz
+2 kHz
Standard
A-Mechanism :
Short-circuit W032
and W033(TPOO3)
when performing double-speed
adjustment.
B-Mechanism :
Short-circuit W031 and W032(TPO03)
when performing double-speed
adjustment, (Be sure to set the deck
to the PLAY mode first before short-
circuiting TP003.
Do not operate the deck while it is
short-circuited.)
The playback level varies when the
head is replaced so should be
adjusted.
Use an electronic voltmeter with an
impedance of 100 kQ or more.
(L) R221
(R) R222
e] &
W021(E) of TPOO1 is -5.5dBs.
(L) R223
(R) R224
Connect a frequency counter between
W015 and W016 of TP002 and
perform recording with a CrO2 tape.
-5 kHz
Recording
{ Record 100 Hz/1 kHz/10 kHz with the
0+3 dB
1) The recording and playback fre-
frequency
NR switch off and -30 dbs input from
for
100 Hz
quencies of a cassette deck are ad-
AUX. While playing back these
and
justed by adjusting the bias. This is
Fesponse
recorded signals, adjust the variation
10 kHz
because the frequency response
of the 100 Hz and 10 kHz outputs
from the 1kHz output to the
standard value using R335 and R336.
(Basically, adjust so that the 1 kHz
and 10 kHz outputs are flat.)
with 1 kHz
depends more on the bias current
than with an open-reel deck.
2) Perform the adjustment with
normal tape and confirm that the
values are within the range for
CrO, tape.
Note:
After completing the recording level adjustment in item 3, check the recording and playback
frequencies with the NR switch on. Fine adjust again if the value is 0+4 dB or more at 1 kHz
and 10 kHz.
20162)
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