AMERITRON AL-80B, Инструкция по эксплуатации

Страница: 25 / 38

AL-80B Instruction Manual
21
11a.
Increase the "ALC SET" voltage (if the ALC is connected) until 180 mA (18 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 200 mA at this
stage. The plate current should not be allowed to exceed 600 mA during brief periods of tuning
(15 seconds).
11b. Increase the exciter drive power (if the ALC is not connected) until 180 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 200 mA at this stage. The plate current should not
be allowed to exceed 600 milliamperes during brief periods of tuning (15 seconds).
12a. For CW operation, the output power should be reduced with the "ALC SET" control until the
rated output power of 800 watts is obtained. The "LOAD" control should be adjusted until
minimum plate current is obtained without dropping below 800 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.
12b.
For SSB operation, the "ALC SET" should be adjusted to allow 200 mA of grid current (near
the 20 volt marking). The exciter should be set to produce maximum output power (not to
exceed 100 watts of peak power). Next the amplifier's "LOAD" and "PLATE" controls are
adjusted for maximum power output on the internal peak reading RF wattmeter with either a
two-tone generator or sustained "HEL-L-L-L-L-O" driving the exciter. The "ALC SET" control
should then be reduced until the peak power output is slightly lowered. Finally the exciter's
audio gain or output power is adjusted until the multimeter "ALC" position indicates the
desired ALC level. This setting should normally allow around 150 mA grid current on a steady
carrier or "whistle".
Note:
If the ALC is not connected, the amplifier must be fully loaded for maximum
output with maximum drive (not to exceed 100 watts). The exciter's output should
then be reduced until 1000 watts PEP is obtained.
"ALC SET" control
Proper adjustment of the front panel "ALC SET" control accomplishes the following:
1. Exciter's power is limited to a value that produces a predetermined maximum grid current in
the amplifier. The front panel "ALC SET" control determines the maximum grid current
obtained.
2. The "LOAD" control setting determines the maximum plate current and output power for a
given grid current. Never exceed 600 mA of short duty cycle (or 400 mA of long duty cycle)
plate current. Never exceed 200 mA of operating grid current.
3. For normal SSB operation, the exciter power should be reduced until the ALC voltage
(measured in the ALC multimeter position) flicks upwards on occasional voice peaks. This
will produce the best audio quality. The drive can be increased for DX or weak signal SSB
operation until the ALC steadily registers voltage.
Also see the "ALC Adjustment" section on page 15, and the "Multimeter" section on page 6.