R.V.R. Elettronica RXRL-NV/2, Technical Manual

Page: 35 / 204

RXRL-NV/2 Technical and Maintenance Manual
R.V.R. Elettronica S.r.l. (Bo) Pag. 35
SETUP 2 / FIG. 6
1) Use an R.F. signal generator to inject a -47 dBm signal into the
R.F. input of the receiver.
2) Using a frequency meter, check the accuracy of the 10.7 MHz IF
(10.700 MHz is acceptable).
Adjust if necessary using compensators C27 and C28 situated on the
PLL card.
3) Using an oscilloscope, adjust TR1 and then TR2, situated on the card,
to maximize the 10.7 MHz IF signal level.
4) Check that the amplitude of the 10.7 MHz IF signal is still 150 mVpp,
and if not, adjust P1 accordingly (take care adjusting P1 not to
increase distortion levels).
5) Now configure the receiver as detailed in SETUP 3 (Fig.7).
6) Inject a 400 Hz tone into the R.F. generator and modulate it with
a deviation of ±100 KHz. The resultant output should be fed to the
R.F. input of the receiver.
7) Check that the MONO (R42) and STEREO (R41) trimmers, situated on
the front panel, are in their maximum position.
8) Measure the MONO signal level output by the receiver into the
audio signal analyzer.
9) Adjust TR3 for the maximum value and TR4 for the minimum.
10) Set the audio analyzer to a measure audio distortion percentage with
a low-pass filter at 30 KHz.
11) Adjust TR3 and TR4, alternately, to obtain the minimum MONO
distortion figure (typically 0.1%). Having optimized the MONO f i g -
ure, the STEREO figure should also be optimized (typically 0.3%).
If this is not the case, adjust P1, TR1 and TR2, taking care not
SETUP 3 / FIG. 7