R.V.R. Elettronica VJ2000, Руководство пользователя

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VJ2000
34 / 44 USER MANUAL Rev. 4.0 - 26/02/01
h) Wait for the automatic protection cycle to complete and repeat step e) to verify the
correct alarm threshold (60 mA).
8.3 Calibration of the Grid Current Meter (IG)
Perform SETUP 3.
1) Switch the IG-IA meter switch to the IG position (5 Fig.1).
2) The unit should be switched off.
3) Adjust the output voltage of the external power supply to 0V.
4) Connect the external power supply to the 2.2 Ohm, 5W resistor R4 situated on the rear
of the meter (current).
The polarity should be such as to produce a clockwise deflection.
5) Increase the power supply voltage and check for a proportional increase in the grid
current (as measured by the VJ2000 meter) and in the current supplied by the power
supply.
6) Adjust trimmer R2 for a correct reading.
8.4 Calibration of Anode Current Measurement (IA)
Perform SETUP 4.
Perform the procedure detailed for the calibration of the grid current measurement, but instead
connect the power supply to the R3 0.22 Ohm resistor found on the same board. Use R1 to
calibrate the IA meter.
8.5 Calibration of Heater Voltage Measurement (HEATER)
1) The unit should must be switched off, perform SETUP 5.
2) Switch the Heater/Plate Voltage meter switch (7 Fig.1) to the Heater position.
3) Connect a dummy load (e.g. P>2KW/50 Ohm) to the RF Output of the amplifier.
4) Connect the External Multimeter on Pin 1-2 of JP2 connector of the Voltmeter Card
(Heater Voltage meter card).
5) Before to switch on the External Multimeter verify that the multimeter selector is on VAC
position.
6) Switch on the tube amplifier and with ST.BY selector (19 Fig.1) switch over ST.BY position.
7) Adjust R2 trimmer of the Voltmeter Card to obtain the same measurement both on the
Voltage Measure Meter (6 Fig.1) placed on the front panel and on External
Multimeter.