JVC RC-X3 - Main Adjustment and Level Check

RC-X3 B/E/G |
Main Adjustment and Level Check
= Amplifier adjustments
Conditions
Power supply voltages : AC 110~ 120/220 ~ 240 V DIN OUT 500 mV (-3.8 dBs)/47 kQ
DC 12 V (from battery) ...G version only
Input levels : CD OUT —11 dBs Headphones — 11 dBs=0.215 V/32 Q
EXT MIC —8 dBs Tone controls: High
DIN IN —8 dB Tape select : Normal
Output levels : Speaker 0 dBs =0.775 V/3 2 Tapes used : Recording normal tape TS-8 (UR)
CD OUT 1.0 V(+2 dBs)/47 kQ chrome tape TS-6
metal tape TS-7
Item Tape used Adjustment/check method Condition Adjustment location
Head azimuth |VTT703 Playback the VTT703 test tape for both A and | Tape/normal Left side screw of
adjustment (10 kHz) B decks and adjust the screw in front of the head | speed PB or R/P Head
for the tape running direction so that the
minimum phase difference is within 2 dB of peak.
zl 4
Tape speed VTT712 Playback the B deck at the position where test | Tape/Normal VR851
adjustment (3 kHz) tape VTT712 has ended and adjust VR85 so that | speed
the speed meter value is within 3000+10 Hz.
Play the VT712 to the end position and confirm | High Speed Confirming
that between 5150 and 5500 Hz are obtained
with the B deck in the Playback condition and the
A deck in record condition.
Checking wow | VTT712 Playback the VTT712 test tape with A and B | Tape/Normal Confirming
& flutter (3 kHz) decks and confirm that the wow & flutter value | speed
is less than 0.35% of JIS, RMS.
Playback VTT724 Playback the VTT724 test tape and confirm that | Tape/Normal
output level (1 kHz) Line-out is ~8 dBs+3 dB. Also make sure at
this time that the L.R. deviation is within 1.5 dB.
Confirming VTT739 With respect to their outputs at 1 kHz, the out- | Deck B
playback puts at Speaker Terminal (add dummy resistor of | playback
frequency 3 2) should be 11+ 4 dB at 63 Hz, and 3 + 4 dB | Tape/Normal
characteristics at 10 kHz. (The Chrom/Metal Position should be
—4 dB+2 dB in response to normal tape.)
Recording bias | (TS-8) | Set beat cut switch $271 to position 1 and ad-|S721 (Beat cut) |L721
frequency Normal tape | just the oscillating frequency to 68 + 1 kHz with! 1 : 68 kHz
L721. (Connect a 1 MQ resistor in series when | 2 : 66 kHz
measuring.) 3: 70 kHz
Rec/Play (TS-8) With respect to their CD OUT at 1 kHz — 20 dB|Deck B During repairs, if the
frequency Normal tape | Confirmate output level 9+4 dB (Rec/PB) at R727 resistance is
characteristics 100 Hz, and 344 dB at 10 kHz cut, 10 kHz will rise. If
the R726 resistance is
| cut, 10 kHz will fall.
Dubbing check | (TS-8) Regarding the outputs at 1 kHz, insert a VTT739
Normal tape | test tape for the output at mechanism A and a
VTT739 TS-8 Normal Tape for the output at mechanism
B and carry out according to the hi-speed dubb-
ing order. With 1 kHz as standard, the output
should be + 12+4 dB at 63 kHz and +344 dB
at 10 kHz.
@ Tuner Section
Basic Conditions:
Power Source of the Receiver : DC 12V or AC 120 V
Tuner Section : 6.85 V
Load Resistance of the Receiver : 5bO mW (0.39 V)/3 2
Modulation of SSG : AM — 400 Hz, 30%
FM — 400 Hz 22.5 kHz Devi.
12 (No. 1755)