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

Page: 46 / 204

RXRL-NV Technical and Maintenance Manual
R.V.R. Elettronica S.r.l. (Bo) Pag. 46
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 and DOWN buttons and confirm
it with the ENTER key.
RECEIVER
1) Select the new frequency with the UP (14 Fig.1) and DOWN (12 Fig.1)
buttons and confirm it with the ENTER key (13 Fig.1).
2) Select the SIGNAL measurement using the selector (20 Fig.1) and
confirmed by the corresponding green led (8 Fig.1).
3) Calibrate the 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
Should the new operating frequency fall within one of the two adjacent
bands (highter or lower), the following procedure should be carried out:
TRANSMITTER
1) Change the EPROM for one containing the desired frequency.
2) After the replacement of the EPROM, set the CPU on the frequency
range relative to the EPROM frequency. When the transmitter switches
on, appears on the display the lightening notice SET 0; now, push
ENTER and verify that the minimum frequency of the EPROM appears
on the display. In case in which appears the lightening notice
SET 1 too, push again ENTER command.
3) Select the new frequency using the UP and DOWN buttons and confirm
it with the ENTER key.
4) Follow the calibration procedure for the VCO, as detailed in
paragraph "Calibration of the VCO" of the PTRL-NV manual.