Technics RS-273US - Page 11

MEASUREMENT & ADJUSTMENT
REMARKS
. Set the tape selector to CrO2 position.
. Measure in the same manner as- above (use test tape
C-RF).
. Make sure that the measured value is within the range
specified in the overall frequency response chart for
CrOz tape below.
Overall Frequency Response Chart (Cr0z2)
7 kHz 13 KHz
VM Ls
4kHz 6 kHz 8 kHz 12 kHz
f
Fig. 24
1. When the frequency response between the middle and
high-frequency range becomes higher than the standard
value, aS shown by the solid line in fig. 24, increase the
bias current by turning VC1-1 or VC1-2 in direction of
arrow indicated on PCB.
. When it becomes lower, as shown by dotted line, reduce
the bias current by turning in the direction opposite to
arrow indication
Note:
1. For adjustment when the bias current is lower than the
standard value 0.1mA, use the procedure indicated in
adjustment 2, because reducing the bias current beyond
this poirit may worsen the distortion factor.
. For the method of bias current measurement, refer to
“Bias Current Adjustment” on page 6.
Adjustment 2—Using the peaking coil for recording equaliza-
tion
4 kHz 6 kHz 8kHz = 12 kHz
_ ——$——— ne
Fig. 25
When the frequency response is flat in the middle-frequency
range and makes a sharp rise or drop in the high-frequency
range as shown in fig. 25, adjust by turning the peaking coil
L5 (L-CH), L6 (R-CH) for recording equalization.
* Location of VCi-1 and
VC1-2 are shown in fig.
26.
* Location of L5 and L6 are
shown in fig. 26.
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