Adjustment Method; Test Instruments Required For Adjustment; Low Frequency Oscillator; Measuring Condition(Tuner Section) - JVC RC-BZ5LB Service Manual

Adjustment method

Test Instruments required for adjustment

1.

Low frequency oscillator

(Frequency range: 50Hz to 20kHz)
(Output: 0 dBs across 600 Ω terminating resistor)
Attenuator(Impedance: 600 Ω)
2.
3. Test Tapes
VT712 For tape speed, wow & flutter check
VT722, 724
VT738 For playback frequency response check
VT702
4. Blank tape TYPE1:AC–225
5. Electronic voltmeter
6. Distortion meter
7. Frequency counter
8. Wow and flutter meter
9. Torque gauge(Cassette type)
10. Test disc
11. Jitter meter
12. TE Offset
Measuring conditions(Amplifier section)
Supply voltage
Reference output level
Reference input level
: –20 dBs supplied to test point CN1
Standard test frequency
Output measuring point
Standard position of switches
Function switch
Beat cut switch
Standard position of controls
Tone
Main volume adjust
For playback, output level check
For head azimuth adjustment
CTG – N
CTS1000
NJM631
LTM9055
AC120V(60Hz)
DC12V(UM–1 x 8)
Speaker
: 0 dBs(0.775V) / 3 Ω
Headphone
: –10 dBs(0.245V) / 32 Ω
1kHz
Speaker terminal
:Dummy load 3 Ω
TAPE
NORMAL
Maximum position
0 dBs output position
Test remarks
1. Negative side of the input and output terminals of the
testing set, shall be isolated from each other. The
negative side should not be commonly connected
when a 2channel electronic voltmeter is connected.
2. A dummy load shall be connected to the output
terminal and the lead wires of dummy load shall be
as thick as possible.

Measuring condition(Tuner section)

Power supply voltage to tuner
Reference output
AM modulation
FM modulation
Remarks for alignment
1. Connect 30 pF capacitor and 33k Ω resistor to the
output terminal of the IF sweeper in series while
0.082 µ F capacitor and 100k Ω resistor to the input
terminal in series.
2. Set the output level of the IF sweeper as low as
adjustable.
3. IF alignment is not necessary for both AM and FM
MPX alignment is not necessary either. All IFTs and
MPX coil are non-adjusting type.
RC-BZ5LB/BZ5RD
RC-BZ6BU
Vcc: DC 6V
Speaker: 0.245V/3 Ω
400Hz, 30%
400Hz, deviation 22.5kHz
1-15