RV-B550BU
1-15
Adjustment method
Measuring devices necessary for adjustment
1. Low-frequency oscillator
It must have the ability to output 600ohm from 0 dBs
at an oscillation frequency of 20 Hz 50 Hz.
2.Attenuator impedance: 600ohm
3.Electronic voltmeter
4.Distortion meter
5.Frequency counter
6.Wow and flutter meter
7.Test tapes
VT-712: tape speed and rotational distortion (3 kHz)
VT-724: standard level (1 kHz)
VT-703: head angle adjustment (10 kHz),
or use VT-73
VT-739: reproduction of frequency characteristics
(1 kHz, 63 Hz, 10 kHz)
8.Blank tape
Type I : AC-225 (TDK-AD)
Type II : AC-514 (TDK-SA)
9.Torque gauge: Tension gauge for playback,
fast-forward and rewind.
FWD (TW211A), REW (TW212A)
and FF/REW (TW2231A)
Specifications for measurement
Power supply voltage ................... AC 100 V (50/60 Hz)
Standard output ........................ Speaker: 0.775V/4ohm
Headphone:0.245V/32ohm
Standard frequency and input level
................... 1 kHz: AUX: -8 dBs
Input level for reproduction of recording characteristics
................... AUX: -28 dBs
Measuring output terminal ................... Speaker: CN633
Load resistance .................................................... 4ohm
Radio input signal
AM frequency ..................................................... 400 Hz
Degree of modulation in AM band .......................... 30%
FM frequency ...................................................... 400 Hz
Frequency deviation in FM band ..................... 22.5 kHz
Tuner section
Voltage input to the tuner .......................... +B: DC 5.7 V
VT: DC 12 V
Standard measuring output ...... 26.1 mV (0.28 V) /3ohm
Input locations ..................... AM: standard loop antenna
FM: TP1 (hot) and TP2 (GND)
Standard settings for measuring volume
Sound ..................................................................... OFF
Effective hyper bass ............................................... OFF
Volume adjustment ........................................... VOL. 23
Precautions for measuring
1.Input 30 pF and 33 kohm to the IF sweeper output
and 0.082 F and 100 kohm to the sweeper input,
respectively.
2.Lower the output level of the IF sweeper as much as
possible in the adjustable range.
3.The IF sweeper needs no adjustment as it is a fixed
component.
4.It is not necessary to perform any kind of adjustment
on the MPX, as a ceramic oscillator is used for
measuring.
5.FM tracking adjustment is not necessary as a fixed
coil is used.
6.The grounding circuit is separate from the input and
output. Therefore, be sure to connect to ground
carefully when measuring both the input and output
voltages simultaneously using 2 channels of the
electronic voltmeter.
7.The speaker's minus terminal cannot be connected to
ground when using a BTL format amplifier. Therefore,
do not connect any type of ground wire to this
terminal. The OTL format is used with this system.
8.Use a large wire to connect to the dummy impedance
generator when measuring the output.
9.Be sure to use a band pass filter (DV-12) when using
mixed tape.
