Palstar Commander VHF-1200, Руководство пользователя

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Switch the OPERATE / STANDBY switch to OPERATE and key the exciter with ZERO
RF drive applied. The red transmit light should come on, along with an indication of plate
idling current on the meter (approx. 100-160 mA VHF-2000; 80-100 mA VHF-1200). Apply a
low level of RF drive (5 W or less) and adjust the LOAD and then the TUNE control for maxi-
mum output as indicated on an external Wattmeter.
COMPLETE THESE ADJUSTMENTS AS
QUICKLY AS POSSIBLE TO AVOID STRESSING THE TUBE(S).
Again key the exciter and while increasing the RF drive, adjust the LOAD control counter-
clockwise
to obtain a peak in output power while keeping the grid current below 60mA. Read-
just the TUNE control
clockwise
for maximum output. Repeat this procedure until the desired
output is obtained. When increasing power output, the TUNE capacitance will increase (clock-
wise on the dial) and the LOAD capacitance will decrease (counterclockwise on the dial) When
properly tuned, the grid current will be peaked at the TUNE setting and turning the LOAD
counter-clockwise will decrease grid current and power output. If the grid current rises, keep
turning LOAD counter-clockwise until it decreases. Do not exceed 600 mA (VHF-1200) or
1000 mA (VHF-2000) of plate current on key down (see typical operating conditions chart on
next page). If you exceed 70 mA (VHF-1200) or 100 mA (VHF-2000) of grid current the am-
plifier will dropout to Standby. To reset it, you will have to un-key the transmitter and reduce
RF drive.
With the meter switch in the Ip position and while monitoring grid current, the Commander
VHF-1200/2000 is ready for on the air operation. Normal SSB operation is indicated by plate
and grid current meter readings on voice peaks of approximately 1/3 to 1/2 of the CW key down
value. For FM or other high duty cycle modes, limit output to 600 watts (VHF-1200) or 1000
watts (VHF-2000) maximum.
If your planned operation is on SSB, you should adjust the load control slightly counter-
clockwise, reducing the output slightly by about 30 to 50 watts. This adjustment is necessary to
insure that the amplifier has sufficient headroom to handle the plate current peaks caused by the
complex voice patterns during SSB operation. Nominal and grid current readings during SSB
operation will be about 30 to 40% of the key down CW readings.
CAUTION:
THE TUNE AND LOAD AIR VARIABLE CAPACITORS
MAY ARC IF MAXIMUM DRIVE IS APPLIED BEFORE THE AMPLIFIER
IS PROPERLY TUNED. ALWAYS FOLLOW THE DESCRIBED TUNE UP
PROCEDURE TO AVOID CAPACITOR ARCING. ARCING MAY ALSO
OCCUR IF YOU ATTEMPT TO TUNE INTO AN ANTENNA WITH A
VSWR GREATER THAN 2:1.
If you should need any further assistance tuning this amplifier, feel free to call us at 1-800-
773-7931 and our staff will be happy to help you. If you are outside the United States we are
available at 937-773-6255