Notes On Adjustment; Adjustment And Checking - Sony WRR-805A Service Manual

3-1-2. Notes on Adjustment

The RF level of the input signal(output level of the signal
generator) for adjustment is expressed as open ended
voltage in unit dBu (0 dBu = 1uV).
The adjustment is to be performed by calibration the output
level of the signal generator as shown below.
Calibration method
(1) Connect the RF milli-voltmeter to the signal generator as
shown in the figure below.
(2) Adjust the level of the output signal from the signal
generator (SSG) so that the RF milli-voltmeter reads 50
mV. The level of the output signal from the signal
generator (SSG) when RF milli- voltmeter reads 50 mV
shall be specified as 100 dBu (at no load).
50-ohm
termination probe
Signal generator
(SSG)
100 dBu
50 Z
OSC
3-2
RF milivoltmeter
(set in 100 mV range)
Adjust the output of
the signal generator
(SSG) so that the
meter reards 50 mV.
50 Z 50 mV

3-2. ADJUSTMENT AND CHECKING

This section describes the following adjustments (and
checking) required to satisfy the specifications.
Adjustment and Checking Item
3-2-1. Reference Frequency (4 MHz oscillation frequency)
Adjustment
3-2-2. Muting level and RF level adjustment
3-2-3. Output level adjustment
3-2-4. S/N checking
3-2-5. Distortion ratio checking
3-2-6. RF indicator level checking
n
= _113 dBm
0 dBuV
EMF
(EMF = Electromotive force)
0 dBm = 1 mW at 50 ohm loaded
WRR-805A (CE, AU)