Fostex A-8 - Page 80

button to rewind tape to the.starting point, put the transport in the PLAY mode
and check the meter reading. The MONITOR switch must be at TAPE.
It is in normal condition if thè meter reading is 0 VU ±1.5 VU.
If it is off spec, correct by adjusting REC LVL R315, 5KÌÌB.
Do the same on the remaining tracks 2^8.
6.4.8 Overall frequency response
1) With the front panel NR IN/EXT switch at EXT and under the measurement setup
of the previous Section 6.4.7, apply signals from 40Hz through 18KHz (15 ips)
and 40Hz through 15KHz (7-1/2 ips) at -lOdBV (0.3V) to the recorder INPUT jack
and set the NR switch to INT.
To adjust TRACK 1, for example, apply the signal'to INPUT 1 and plug in a level
meter to OUTPUT jack 1. Put TRACK 1 in the record mode to record a certain length
of the signal, rewind it to the start, and playback the tape. It is in good
normal condition if the frequency response in reference to 400Hz is within +3dB
and -3dB.
If it does not fall within spec in the high frequency region, correct it by a
slight rotation of REC EQ pot R316, 1KSÌB.
2) Check and adjust the remaining tracks in the same way.
6.4.9 Overall S/N measurement
1) Set the front panel NR INT/EXT switch at INT.
2) Upon completing checking up to Section 6.4.8, apply a 400Hz, -lOdBV (0.3V) sig 
nal to the rear panel INPUT jack 1 (example for track 1), record the signal onto
a blank tape, then, without stopping the tape, unplug the oscillator connected
to the INPUT jack and further record a length of no-signal tape.
3) Plug a level meter into OUTPUT jack 1, playback the recorded signal section to
measure the noise level of the no-signal section against the 400Hz reference
level, calculate the difference between noise level and reference level, add
12dB to it and obtain the ratio between peak recording level and noise level.
Specification : 72dB weighted
60dB unweighted
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