Nautel XL12, Технические инструкции

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12 000 WATT AM BROADCAST TRANSMITTER
XL12
Page 3-10
01 January 2002
Table 3-1 Control/Monitor Panel Controls and Indicators (Continued)
PANEL MARKING/
REF FIG NOMENCLATURE FUNCTION
DES NO. USED IN TEXT
A1A3S1 MD-3
♦
CONTROL - ∧ ∧
(INCR RF PWR)
Push button switch that causes an incremental increase in
the RF output level (total of 1000 increments from zero to
maximum), by controlling the magnitude of the PDM's
carrier reference voltage, when it is depressed (integral
lamp will turn on while held depressed). The first increment
occurs 0.25 seconds after actuation. If the switch is
momentarily pressed and released the RF output will
increase by one increment. If the switch is held depressed,
the RF output will increase to a nominal maximum of
13.5kW. The RF output will remain at the level present
when the switch is released and will become the preset
level for the current preset RF power level selection.
NOTE
Switch actuation will increase the carrier reference
voltage, for the selected preset RF power level, even if the
RF power stage is off (not producing an RF output).
When the RF power stage is turned on, the RF output will
be greater than the last established level for that preset
power level.
In addition to increasing the carrier reference voltage (RF
output), the
CONTROL
- ∧ ∧
switch will/may cause the
following to occur:
If it is not released prior to attaining a carrier reference
voltage that corresponds to 13.5kW, the increase integral
lamp will extinguish. The power will not continue to
increase. This status will be maintained until the carrier
reference voltage is reduced by pressing the
CONTROL - ∨ ∨
(DECR RF PWR)
switch or it is reset to zero by
simultaneously pressing and releasing
CONTROL -
∧ ∧
and
CONTROL -
∨ ∨
switches.
If the
CONTROL - ∨ ∨
and
CONTROL - ∧ ∧
switches are
simultaneously actuated, the carrier reference voltage and
therefore the RF output level will be set to zero. All six of
the preset power level selections will be affected (set to
zero).
If it is actuated when the RF output is reduced (cutback)
because a protection circuit has automatically reduced it to
a safe operating level (the
RF POWER - CUTBACK
status
indicator's display is red), the RF output will be restored to
the original preset power level in one step.