AL-800H Instruction Manual
21
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STEPS 10a AND 11a REQUIRE A CONNECTION FROM THE AMPLIFIER'S ALC OUTPUT TO
THE EXCITER'S ALC INPUT.
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STEPS 10b AND 11b SHOULD BE USED IF THE EXCITER AND AMPLIFIER ALC LINES ARE
NOT CONNECTED.
NOTE:
Step number 10 requires the simultaneous observation of the plate current (Ip) and the grid
current (Ig).
10a.
If the ALC line is connected, adjust the exciter's drive or power output control to maximum.
NEVER
ALLOW THE GRID CURRENT (Ig) TO EXCEED 75 mA OR THE PLATE CURRENT (Ip) TO
EXCEED 1.2 AMPERES AT THIS STAGE OF TUNING.
If
either
current exceeds these limits,
reduce
the "ALC SET" control. Adjust the
"PLATE"
control for maximum output power. The plate current
(Ip) of the amplifier and the output power of the exciter should dip (decrease) when this adjustment is
made.
10b.
If the ALC is not connected, place the exciter in the transmit mode and gradually increase the drive
until a
grid current
of 50 mA
or
a
plate current
of 0.5 ampere (whichever is higher) appears. The
"PLATE"
control should be adjusted until maximum grid current and maximum RF output power
appear. The plate current (Ip) should now dip slightly. The drive power should be removed.
11a.
Increase the
"ALC SET"
voltage (if the ALC is connected) until 70 mA (14 volts) is indicated. Apply
full drive (not to exceed 100 watts) and adjust the
"LOAD"
and
"PLATE"
controls for maximum RF
output power. The grid current should not be allowed to go above 100 mA at this stage. The plate
current should not be allowed to exceed 1.5 ampere during brief periods of tuning (30 seconds).
11b.
Increase the exciter drive power (if the ALC is not connected) until 70 mA of grid current is indicated.
Adjust the
"LOAD"
and
"PLATE"
controls for maximum RF output power. The grid current should
not be allowed to go above 100 mA at this stage. The plate current should not be allowed to exceed
1.5 ampere during brief periods of tuning (30 seconds).
12.
For CW operation, the output power should be reduced with the
"ALC SET"
control until the rated
power of 1500 watts CW is obtained. The
"LOAD"
control should be adjusted until minimum plate
current is obtained without dropping below 1500 watts. The exciter's power can be reduced until the
multimeter shows a slight upward flicker with the
"MULTIMETER"
switch in the ALC position if
the ALC is used.
13.
For SSB operation, a two-tone generator or sustained "HEL-L-L-L-L-O" can be used. The exciter
should be set to produce the maximum output power (not to exceed 100 watts of average power). The
amplifier's
"LOAD"
control is adjusted for maximum power on the internal peak reading RF
wattmeter. The
"ALC SET"
control is adjusted until a peak power output of 1500 watts (or less) is
obtained. Finally the exciter's audio gain or output power is adjusted until the multimeter
"ALC"
position indicates the desired ALC level.
NOTE: If the ALC is not connected, the amplifier should be fully loaded with maximum drive (not
to exceed 100 watts). The exciter's output should then be reduced until 1500 watts is
obtained.
