R.V.R. Elettronica PTRL-NV/2/HP/S3, Техническое руководство

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R.V.R. ELETTRONICA S.r.l. (BO) Pag. 46
PTRLNV/2/S3 and PTRL-NV/2/HP/S3 - Technical and Maintenance Manual
6.4 STEREO SEPARATION
Stereo separation is measured using a stereo coder, a stereo
demodulator. The figure is obtained from the ratio of the left and right
channel outputs with only the left channel modulated, for frequencies
between 30 Hz and 15 KHz.
To make this measurement, configure the unit according to SETUP C (Fig.11)
and carry out the following procedure:
1) Adjust the variable attenuator for a value dependent from the
transmitter's output power (Table E).
2) Adjust the signal generator for an output level of -10 dBm at the
right input (and subsequently the left) of the stereo coder.
3) Check that the reading form the output of the stereo decoder is
better or equal to 47 dB (both at 400 Hz and 10 KHz).
4) Repeat the operation for both channels with a modulating tone of
400 Hz and 10 KHz. The maximum difference should be ±3 dB.
6.5 CHANGING FREQUENCY
There are three different procedures for changing frequency,
depending on the new frequency to be selected:
CASE A - Should the new frequency fall within the range of receiver's
R.F. Power Amplifier Stage (and relative receiver's Front-End/
Mixer).
CASE B - Should the new frequency fall outside the range of receiver's
R.F. Power Amplifier Stage (and relative receiver's Front-End/
Mixer).
CASE A
Should the new frequency fall within the range of receiver's R.F. Power
SETUP C / FIG. 11