R.V.R. Elettronica RXRL-NV/2, Техническое руководство

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RXRL-NV/2 Technical and Maintenance Manual
R.V.R. Elettronica S.r.l. (Bo) Pag. 44
6) Use the modulation analyzer to make the S/N measurement and check
that the figure is better than 60dB (measured on each demodulated
and de-emphasize single channel) for the RXRL-NV/2 receiver.
6.4 STEREO SEPARATION
Stereo separation is measured using a stereo coder, a stereo demodulator
and an audio analyzer. The figure is obtained from the ratio of the left and
right channel outputs with only the left (or only right) channel modulated,
for frequencies between 30Hz and 15KHz.
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 audio generator for an output level of -10dBm at the
right input (and subsequently the left) of the stereo coder.
3) Check that the reading from the output of the stereo decoder is
better or equal to 40dB (both at 40Hz and 15KHz).
4) Repeat the operation for both channels with a modulating tone of
400Hz and 10KHz. The maximum difference should be ±3dB.
6.5 CHANGING FREQUENCY
The are two 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)
SETUP C / FIG. 11