500 WATT RADIOBEACON TRANSMITTER
ND2000A-02x-xx0
Page
4-5
15 January 2005
Table 4-2 Control/Monitor Panel Controls and Indicators
PANEL MARKING/
REF
FIG
NOMENCLATURE
FUNCTION
DES
NO.
USED IN TEXT
A1A1DS1
MD-2
STANDBY-ALARM
When turned on, indicates the transmitter has switched
from the selected main-side to standby-side.
A1A1DS2
MD-2
SWR-ALARM
When turned on, indicates a reflected power in excess
of 60 watts has been sensed at the output of the
harmonic filter.
When the dc option is not installed, it may indicate the
ac power is more than 10% low.
A1A1DS3
MD-2
SHUTDOWN ALARM
Turns on when the transmitter has shut down.
A1A1DS4
MD-2
RF CURRENT ALARM
When turned on, indicates troughs of modulation
envelope, as sensed by an RF current probe at the
harmonic filter's input are exceeding the preset
overmod threshold. Normally turns on when the
antenna impedance is less than 50 ohms at the
sideband frequency and the antenna current is
exceeding the current that would be present if the
antenna impedance was 50 ohms.
A1A1DS5
MD-2
BATTERY-ALARM
When turned on, indicates transmitter's B- voltage is
being provided by an external dc power source
(battery).
A1A1DS6
MD-2
RF ON
When turned on, indicates operating voltage for the
subject transmitter is being supplied by the ac power or
dc power source.
A1A1DS7
MD-2
CONTROL-REMOTE
Turns on when the
CONTROL
switch is set to
REMOTE
and the on/off switching facility has been extended to a
remote site.
A1A1DS8
MD-2
MONITOR - BYPASS
When turned on, indicates
MONITOR
switch is set to
BYPASS
and changeover is inhibited.
A1M1
MD-2
TEST-Power/Mod
Displays parameter selected by the
TEST-Power/Mod
switch. Forward and reflected power readings are
obtained from the upper scale. Modulation percentage
readings are obtained from the lower scale.
A1M2
MD-2
TEST-Volts/Current
Displays parameter selected by the
TEST-Volts/Current
switch. Voltage readings are obtained from the upper
scale. Current readings are obtained from lower scale.
