Palstar COMMANDER HF-2500 EXPORT, Руководство пользователя, Страница: 13 / 30

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case it is inadvertently keyed when the switch is thrown). Key the exciter with no RF drive ap-
plied. The red transmit LED should illuminate, and the meter should indicate approximately
120 mA of plate current. Apply 5 to 10 watts of RF drive, the plate current should rise slightly.
If the plate current rises above 1200 mA, reduce drive. Adjust the
TUNE
to achieve maximum
output power as indicated on an
EXTERNAL WATTMETER
..
COMPLETE THESE AD-
JUSTMENTS AS QUICKLY AS POSSIBLE TO AVOID STRESSING THE TUBES
.
Adjust the
LOAD
control to reduce grid current while maintaining output power as indi-
cated on the relative output meter or an external Wattmeter. Next, increase the drive in small
increments and
adjust the LOAD control to REDUCE the grid current .
Under normal con-
ditions the grid current should not exceed 15-20mA at maximum power output.
Readjust the TUNE control to again peak the power output. If the grid current rises above
100mA. quickly reduce drive by adjusting the
LOAD
control
clockwise
to reduce grid current.
Repeat these adjustments as required to achieve the desired output up to 1500 Watts.
[NOTE: Avoid operation at high grid current levels (~60mA or greater). If the grid current
is allowed to reach or exceed 120mA, the controller will immediately un-key the amplifier and
the “Status-Trip” LED will flash rapidly, indicating that a grid current limit (a “Grid-Trip”) has
occurred.
In order to reset the Grid-Trip circuitry, the exciter must be un-keyed and the “Standby-
Operate” switch must be switched to “Standby” and then back to “Operate.” Once the Grid-
Trip has been reset, the “Status-Trip” LED will stop flashing and remain illuminated.
Do NOT exceed 1200mA plate current.]
Note that when increasing output power the tune scale will always read higher and the load
will read lower. Also, the supplied inspection sheet has all of these settings and they should be
used as a guide for this procedure. If your settings vary widely from these you have something
wrong and should start over.
If your planned operation is on SSB, you should reduce the load control slightly counter-
clockwise, reducing the TOTAL output slightly about 30 to 50 Watts. This adjustment is neces-
sary to insure that the amplifier is sufficiently loaded to handle the plate current peaks caused
by the complex voice patterns during SSB operation.
Nominal plate and grid current read-
ings 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. AL-
WAYS FOLLOW THE DESCRIBED TUNE-UP PROCEDURE TO AVOID CAPACITOR
ARCING. ARCING MAY ALSO OCCUR IF YOU ATTEMPT TO TUNE INTO AN AN-
TENNA WITH A VSWR GREATER THAN 2:1.
Expect to use the TUNE CONTROL to peak the power output and
and rotate the LOAD control CLOCKWISE to lower the grid current.