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ADJUSTMENTS
1. Head azimuth adjustment.
2. Bias current.
3. Playback gain.
4, Overall gain.
5. Playback frequency response.
I. TEST
INSTRUMENTS
1. Prepare test instruments which are equivalent in accuracy to those shown below.
4. Specifications of test instruments.
(1) Audio frequency oscillator
a. Oscillation frequency:
5Hz~ 500 kHz (5 ranges)
b. Frequency tolerance:
+(3% +1Hz)
c. Sine wave
* Output voltage (at 25°C):
5Vrms £10% (without load)
2.5Vrms +10% (with 6002 load)
* Output frequency response:
Within £0.2 dB, 20Hz~20kHz
Within £0.5dB,
5Hz~ 500 kHz
* Distortion factor:
Not more than 0.05%, 200 Hz ~ 20kHz
Not more than 0.5%, 5Hz~ 500 kHz
* Output impedance:
6002 unbalanced, within + 15%
* Output attenuator:
OdB, 20dB, error; within +0.2dB
d. Temperature in use of set:
Temperature
= 0 ~ 40°C, humidity
= 90% or less
(2) Automatic-stop distortion meter (with vacuum tube voltmeter)
A. Distortion factor measurement
a. Frequency (fundamental wave):
= 400Hz, 1kHz
+10%
b.
Measurement:
0.1~ 100% (6 ranges)
c. Input:
50mV~50V
d. Fundamental wave attenuation:
60 dB or more
B. Level measurement
a.
Measurement:
mV (—60 dB) ~ 30 V (30 dB) (9 ranges)
b. Frequency response (1kHz basis): 20Hz~100kHz
£0.3¢dB
c.
Input impedance:
1MQ2 +10%, less than 50 pF
d. Error in indicated value:
Within £3% at 1kHz
C. Output terminal
a. Frequency response:
OQHz~100kHz
+1dB
100kH2~1MHz
+3dB
b. Output voltage:
1Vrms + 10% (1kHz sine wave)
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