R.V.R. Elettronica PTRL-NV/S3, Technical Manual

Page: 39 / 171

R.V.R. ELETTRONICA S.r.l. (BO) Pag. 37
PTRLNV/S3 - Technical and Maintenance Manual
CHAPTER 5
CALIBRATION OF MODULES
5.1 CALIBRATION OF THE R.F. POWER AMPLIFIER
After replacement of the amplifier, the following procedure
should be followed SETUP 1 (Fig.4):
SETUP 1 / Fig.4
1) Connect a bypass wattmeter between the R.F. output and 50 Ohm dummy
load.
2) Switch on the transmitter and wait for the PLL to lock and the power
output to be enabled.
3) Turn the PWR ADJ trimmer (10 Fig.1) clockwise until maximum output
power is obtained.
4) Use the external wattmeter to adjust the trimmer for a power output
of 2 W (5 or 10 W for other versions).
5) Set the meter selector (13 Fig.1) to FWD and adjust R21 on the
Anameter card for a reading of 2 W on the transmitter’s own meter
(17 Fig.1).
6) Disconnect the dummy load from the exciter output and check that
the power reduces and that the SWR led (15 Fig.1) switches on.
Adjust R8 on the power supply card for a reading of 50% of maximum
direct power on the internal power meter.
7) Re-connect the dummy load and verify that the output power returns
to 2 W.
5.2 CALIBRATION OF THE POWER SUPPLY
The only adjustment required after replacement of the power supply
are those detailed in 5.1 (Calibration of the R.F. Power Amplifier).
It is sufficient to follow steps 1 to 7 of this procedure after the power