JVC D-M3 - Page 12

D-M3 A/B/C/E/J/U
Step Item Adjustment Adjusting Standard Remarks
point value
3 Adjusting 1. Apply a 1 kHz, approx. — 10 dB signal | VR151 0 VU The level difference between left and
recording to the LINE IN terminals. Adjust the 251 right channels for SF/NORMAL tape
level recording level controls until the signal and metal tape should be less than
is available at — 8 dBs at the LINE OUT 1 dB. Perform the adjustment using a
terminals. normal tape, level difference between
2. After checking to see if the Peak level recording and playback for metal tape,
indicator become O, record the signal should be less than 1.5 dB, and that
applied to both left and right channels between left and right channels should
using normal tape. also be less than 1 dB.
3. Play back the recording part. Perform
the recording signal adjustment with
VR151 and VR251 so that the peak
level indicator become O.
4 | Checking 1. Record a 1 kHz, —8 dBs signal to LINE SF/NORM Be sure to perform this adjustment
record/ IN terminals and perform recording with tape; Less following bias current and recording
playback the peak level indicator become O. than 3% level adjustments.
signal 2. Play back the recorded part.
distortion Check the output with a distortion Metal
meter to see if the value conforms to tape: Less
the standard value. than 2%
5 Checking 1. Record a 1 kHz, O dB signal. Stop the in- SF/NORM,
signal to put by disconnecting from the terminal tape.
noise ratio to perform nonsignal recording. More than
in record- 2. Play back the recorded part. Measure 52 dB
ing/play- the O dB recording output and the non-
back signal recording output for comparison
using an electronic voltmeter.
Check to see if the value conforms to
the standard value.
Checking . Apply a 1 kHz signal to the LINE IN More than For the measuring, connect a band pass
erasing terminals. Adjust the recording level 60 dB filter between the deck and the elec-
coefficient controls until the peak level indicator tronic voltmeter.
become O dB.
2. Perform recording with the signal kHz 0 dB eee
enhanced by 10 aB. +20 dB) erasing)
3. Erase a part of the recording.
4. Measure the output difference between
the erased part and nonerased part to filter voltmeter
compare with an electronic voltmeter. (1 kHz)
i alee Hoid less than 1 Sipe mm gap to the magnet from the hall IC.
Auto stop -0.5
ee |
No. 4213
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