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

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R.V.R. ELETTRONICA S.r.l. (BO) Pag. 47
PTRLNV/S3 - Technical and Maintenance Manual
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 selectable by the CPU (and
without the requirement of a change of EPROM), the following procedure
should be carried out:
TRANSMITTER
1) Select the new frequency with the UP (11 Fig.1) and DOWN (8 Fig.1)
buttons and confirm it with the ENTER (9 Fig.1) key.
RECEIVER
1) Select the new frequency with the UP and DOWN buttons and confirm
it with the ENTER key.
2) Select the SIGNAL measurement using the selector and confirmed by
the corresponding green led.
3) Calibrate the 6 compensators, situated on the two filters FIL1 and
FIL2 of the Front-end Mixer, for the maximum R.F. signal, checking
against the corresponding reading on the receiver's meter (maximum
R.F. signal displayable = -47 dBm).
CASE B
THIS PROCEDURE SHOULD ONLY BE CARRIED OUT BY QUALIFIED PERSONNEL
USING THE CORRECT TEST EQUIPMENT. ERRORS CAN CAUSE SERIOUS DAMAGE TO
EQUIPEMENT AND WILL AUTOMATICALLY NULLIFY THE WARRANTY.
Should the new operating frequrency fall within one of the two adjacent
bands (higher or lower), the following procedure should be carried out:
TRANSMITTER
1) Change the EPROM for one containing the desired frequency.