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Troubleshooting
Basic troubleshooting
of a cassette tape
deck is similar to troubleshooting any other
electrical or electronic equipment. Always
check the most obvious possible causes first.
To give you a few ideas of what to look for,
check the following:
e No power: Is the power cord connected?
Tape begins running when power is turned
on: Is the TIMER function on?
DOLBY HX PRO
Dolby HX Pro is an "active bias" technique
that can improve the quality of audio tape
recordings. High-level high frequencies can
be
recorded
more
accurately,
without
sacrificing signal-to-noise ratio, while such
side effects of tape saturation as distortion
are reduced.
What Is Bias?
Bias is a very high-frequency signal generat-
ed within a tape deck and recorded on the
tape
simultaneously
with
the
program
material. This inaudible signal allows a low
noise, low distortion recording and flat
frequency response. Different magnetic tape
formulations
require
different
amounts
of bias for optimum performance. If the
bias
level
is too
high, high-frequency
Maximum Output Level (MOL) decreases.
The Problem of Self-Bias
Unfortunately, bias level is often influenced
by the signal
being recorded. The high fre-
quencies contained in some music act as
bias. This unpredictable source of bias is
added to the existing bias, resulting in a loss
of high-frequency response. As the high-
frequency content of the signal increases,
No
audio
output:
Are all connections
properly made?
Degraded
sound
quality: Are the heads
dirty
or
magnetized?
Are
you
using
good
quality
tape?
Is the proper
NR
System select switch on?
Unable
to select record mode: Are the
record
protection
tabs
on
the tape
in
place?
the ability of the recorder to record high
frequencies (MOL) decreases. This pheno-
menon is called self-biasing.
The Dolby HX Pro Solution
The
Dolby HX
Pro monitors the high-
frequency content of the program material
and adjusts the recorder bias oscillator to
maintain a constant total bias level. The
result is improved
high-frequency response
and lower distortion. Depending on the type
of tape, the improvement in headroom can
be 6 dB or more.
The Benefits
With Dolby HX Pro, it is easier to make
more accurate recordings of the kind of
music which contains high-level high fre-
quencies. The improvement is similar to
that of high-performance tape over conven-
tional tape, so regardless of the type of
tape used, the results will sound better.
Most
important
of all, Dolby
HX Pro
requires no decoding process.
Once the
tape is recorded with it, the improvements
will be realized when playing the tape back
on any machine.
+10
dB
°
250nWb/m
T
HX PRO on
HX PRO off
-30
40
20Hz
50
100 200
500
1k
2
5
10 20k
Example of improved frequency response using Dolby HX Pro function
Specifications
Track System 4-Track, 2-Channel Stereo
Heads 3: 1 Erase, 1 Record and 1
Playback (Combination)
je Cassette tape C-60 and C-90
s type)
Tape Speed 4.8 cm/sec. (1-7/8 ips)
Motors 2: 1 DC Servo motor
(for capstan drive)
1 DC motor
(for reel drive)
Wow and Flutter
0.045 % (W. RMS)
Frequency Response (Overall) -20 dB
15 — 21,000 Hz +3 dB Metal Tape
15 — 20,000 Hz +3 dB CrO, Tape
15 — 18,000 Hz +3 dB Normal Tape
Signal-to-Noise Ratio (Overall)
60 dB (NR OFF, 3% THD Level,
Weighted)
70 dB (Dolby B In, over § kHz)
80 dB (Dolby C In, over 1 kHz)
Fast Winding Time Approximately 90
seconds for C-60
Inputs Line: 60 mV, 50k ohms
Outputs Line: 0.37 V for load impedance
of 50k ohms or more
Headphones: 1 mW/8-ohm load
Power Requirements 120/230 V
AC, 50 - 60 Hz (General export
models)
120 V AC, 60 Hz (U.S.A./Canada)
230 V AC, 50 Hz (Europe)
240 V AC, 50 Hz (Australia)
Power Consumption 16 W
Dimensions (W x H x D)
435 X 147 X 290 mm
(17-1/8" X 5-13/16" X 11-7/16")
Weight 4.8 kg (10.56 Ibs.)
Standard Accessories
Input-output connection cords x 2
e Specifications were determined using metal
tape except-as noted.
e Improvements may result in specifications
or features changing without notice.
Photos ahd illustrations may differ slightly
from production models.
Since this unit incorporates
micro-
computers, it may not operate correctly
because of external noise, etc. In such a
case, confirm that the TIMER switch is in
the OFF position, then switch off the
power once for approx.
one minute
before restarting operation from the
beginning.
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