500 WATT RADIOBEACON TRANSMITTER
ND2000A-02x-xx0
Page
4-8
15 January 2005
Table 4-4 Exciter Module Controls and Indicators
PANEL MARKING/
REF
FIG
NOMENCLATURE
FUNCTION
DES
NO.
USED IN TEXT
A1DS1
MD-17
KEYER FAULT
Indicates a problem has occurred with one or both
EEPROMs on the keyer PWB. Action taken on the
transmitter is dependent on the setting of the
ENBL/DSBL
jumper (E4).
A1E1/
A1E2
MD-17
400/1020
Shunt posts that determine the keyed tone frequency of
the keyer PWB
Installed to short pins 1 and 2 for 1020 Hz.
Installed to short pins 2 and 3 for 400 Hz.
A1E3
MD-17
INT/EXT
Shunt post that determines the keyed tone source
Installed in
INT
position (shorting pins 1 and 2) for an
internal tone oscillator.
Installed in
EXT
position (shorting pins 2 and 3) for an
external oscillator..
A1E4
MD-17
ENBL/DSBL
Shunt post that determines the action taken when a
keyer fault occurs.
When installed in the
ENBL
position (shorting pins 1
and 2), the fault inhibits the
keyed tone
output. A
continuous tone will be generated when this occurs.
When installed in the
DSBL
: position (shorting pins 2
and 3), the fault, although indicated by
KEYER FAULT
lamp DS1, has no effect on the
keyed tone
output.
A1S1
A1S4
MD-17
Keyer Setup Switches
Pushbutton switches S1 (up), S2 (left), S3 (right) and
S4 (down), and alphanumeric displays U11 through
U14, are used to configure the keyer’s contents (type,
characters, standby ‘1’ code, frame type and frame
length). Pressing S2 and S3 simultaneously enters the
setup menu. This menu is used to set up all aspects of
the keyer. To navigate the setup menu, S1 increments,
S4 decrements, S2 backs up,, and S3 accepts and
proceeds to the next selection.
A1U11
A1U14
MD-17
Keyer Content Display
Alphanumeric displays that, during normal operation,
indicate the keyed characters (after setup, display
inactive until a pushbutton switch is pressed). In
conjunction with switches S1 through S4, the displays
are used to set up/change the keyer contents. When all
characters display a ‘!’ character, a fault exists with the
keyer PWB’s EEPROM(s).
