AMERITRON AL-572, Инструкция по эксплуатации

Страница: 27 / 38

Ameritron AL-572 Instruction Manual
25
*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 750 milliamperes except during brief periods (15 seconds
or less).
*12a. For CW operation, the output power should be reduced with the "ALC SET" control until
the rated output power of 1000 watts is obtained. 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 120 mA of grid current
(near the 12 volt marking). The exciter should be set to produce maximum output power
(not to exceed 110 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 just reduced
slightly. 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
120 mA grid current on a steady carrier or "whistle".
Note: If the ALC is not connected, the amplifier should be fully loaded with maximum
drive (not to exceed 110 watts). The exciter's output should then be reduced (either
with the microphone gain or power output control until the output power shows a
very slight reduction.
"ALC SET" control
Proper adjustment of the front panel "ALC SET" control accomplishes the following:
1. The exciter's power is limited to a value that will produce a fixed amount of grid current in
the amplifier. The front panel "ALC SET" control determines the maximum grid current
that can be produced.
2. The "LOAD" control setting will determine the maximum plate current and output power
for a given grid current. Never exceed 750 mA of long duty cycle (more than 15 seconds
without a 15 second cool down period) 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 M
ETERING
, C
ONTROLS
,
AND
A
DJUSTMENTS
" section beginning on page 17,
and the
"
M
ULTIMETER
"
section beginning on page 9.