AMERITRON AL-80B, Инструкция по эксплуатации

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AL-80B Instruction Manual
14
"STBY-OPR" Switch
This switch disables the amplifier's internal antenna relay. In the "STBY" position the amplifier is
bypassed without turning the tube's filaments or the power supply off.
This switch will also reset the grid protection circuit if an optional grid overload protection circuit is
installed. The overload circuit will be reset whenever this switch is placed in the "STBY" position
and returned to the "OPR" position.
"PLATE" Control
The "PLATE" control adjusts the output tank circuit to resonance. This control should always be
adjusted for maximum RF output power. Maximum RF output power normally occurs
simultaneously with maximum grid current and very close to the plate current "dip."
"LOAD" Control
This control adjusts the coupling of the amplifier to the antenna or load. This adjustment insures
optimum coupling between the tube and the load as the SWR of the load, the operating frequency,
or the power level is changed. Advancing the "LOAD" control clockwise increases the RF power
output capability and the linearity of the amplifier. Advancing the "LOAD" control also
decreases
the grid current and increases the plate current for a given amount of drive.
The efficiency of the amplifier and the grid current decrease if the "LOAD" control is rotated
beyond the point of maximum output. The linearity, however, will increase. The proper position for
this control is
slightly clockwise from the setting that produces maximum output with full drive
power applied to the input. Never use this control to adjust the output power .
The "PLATE" control should always be checked after the "LOAD" control is adjusted by more than
one number. This is especially important at the high end of the "LOAD" range on 20 meters and
above. For example, if the "LOAD" is advanced from 7-1/2 to 8-3/4, the "PLATE" should be re-
tuned. If the "LOAD" is touched up only a slight amount, the "PLATE" setting will not usually
require re-adjustment.
ALC Metering, Controls, and Adjustments
ALC Metering Functions
The "MULTIMETER" switch in the AL-80B has two positions that indicate the functioning of the
ALC circuit. These positions are as follows:
ALC In this position the multimeter measures the output voltage of the ALC detector. The
full scale reading of the ALC detector is 35 volts. It is read directly from the ALC/ HV
scale of the multimeter. The multimeter will indicate the maximum value of ALC
voltage available from the internal ALC circuit. The meter should flick upwards
occasionally during normal ALC action in this position.