Nautel XL12, Technical Instructions

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12 000 WATT AM BROADCAST TRANSMITTER
XL12
Page 3-4
01 January 2002
Table 3-1 Control/Monitor Panel Controls and Indicators (Continued)
PANEL MARKING/
REF FIG NOMENCLATURE FUNCTION
DES NO. USED IN TEXT
A1A2DS8 MD-3
♣
-15V
When turned on, indicates the output voltage of the active
exciter's regulated -15 VDC power supply is selected as the
DC voltage to be displayed by the DC
VOLTS
meter (read
0-200 scale and divide by 10).
A1A2S1 MD-3
♣ SELECT METER SCALE
(DC Volts
)
Push button switch that selects which DC voltage (B+, PA
Volts, +48 VDC, +24 VDC, +15 VDC, +5 VDC, -5 VDC, or -15
VDC) will be displayed on the DC
VOLTS
meter when the
meters are enabled. Selection will toggle sequentially to the
next option each time the switch is pressed and released.
A1A3DS1 MD-3
♦
RF INTERLOCKS - INTERNAL
Bi-colour display which indicates status of internal
interlock circuit.
Display is green when circuit is intact.
Display is red when an internal interlock is open because a
ground wand has not been properly returned to its holder
(RF power stages will be turned off).
A1A3DS2 MD-3
♦
OUTPUT NETWORK -
VSWR
Bi-colour display which indicates the status of the RF
output's terminating impedance by monitoring the reflected
power level.
Display is green when the peak reflected power is less than
2000 watts (terminating impedance is acceptable).
Display is red when the impedance seen by the RF output
(carrier and/or sidebands) results in a peak reflected power
of more than 2000 watts.
A1A3DS3 MD-3
♦
RF POWER MODULES
Bi-colour display which indicates the operating status of
RF power modules.
Display is green when all installed modules are operating
and contributing to the RF output.
Display is red when the output of one or more RF power
modules has been inhibited because a malfunction has
occurred or an over temperature condition exists or
inhibited for service removal (RF output level will be
reduced from the preset level).
A1A3DS5 MD-3
♦ EXCITER - EXTERNAL PDM
INHIBIT
Bi-colour display which indicates status of the externally
produced PDM inhibit control input (normally provided by
antenna switching circuitry to ensure RF output is not
being produced during openings and closures of switch
contacts).
Display is green when a PDM inhibit command is not being
applied.
Display is red when an external PDM inhibit command is
being applied (RF output shall be inhibited).