Fostex 600 - ALIGNMENT PROCEDURES; BIAS ADJUSTMENT; CALIBRATION OF L.E.D. LEVEL INDICATORS

ALIGNMENT PROCEDURES
BIAS ADJUSTMENT
Note: Both CHANNEL 1 and CHANNEL 2 level controls should be in fully counterclockwise
position (- 00 db).
Indicator
Adjustment
Remarks
DC Voltmeter VR601a
(CHANNEL 1)
VR601b
(CHANNEL2)
Adjust for 5-10 mV reading
on DC Voltmeter across R634a
(CHANNEL 1) or R634b (CHANNEL
2) with no load.
CALIBRATION OF L.E.D. LEVEL INDICATORS
input output
Alignment connections
STEP
Signal Generator
Frequency set to
Output
Indicator
Adjustment
Adjust for
1
1 kHz
(Sine Wave)
AC Volt¬
meter con¬
nected to
CHANNEL
1 or 2
Signal
Generator
output
Adjust for 40 VRMS
(Model 600), 28.3V RMS
(Model 300) on AC Voltmeter
with no load.
2
Same as
STEP 1
Same as
STEP 1
Same as
STEP 1
Adjust for 28.3V RMS
(Model 600), 20V RMS
(Model 300).
This means -3 dB output
level compared with STEP 1.
3
Same as
STEP 1
LED level
Ind.
CHANNEL
1 or 2
VR701 or
VR702
Adjust for very weak
brightness on 0 dB Indicator
LED with output signal level
of above STEP 2.
4
Same as
STEP1
Same as
STEP 3
Check up the 0 dB indicator
LED brightness is the same
as other LED's with output
level of above STEP 1.
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