500 WATT RADIOBEACON TRANSMITTER
ND2000A-02x-xx0
Page 5-19
15 January 2005
(i) Verify transmitter is operating at the intended
carrier level (500 watts maximum) and the
intended modulation depth.
(j) Connect a multimeter between TB2-1(+) and
TB2-2(-).
(k) Indication on multimeter, just prior to
SHUTDOWN-ALARM
lamp turning on, shall be a
nominal -42.0 V dc.
(l) When battery voltage decreases below the
nominal -42.0 V dc,
SHUTDOWN ALARM
lamp
shall turn on. The transmitter will shut down.
(m) Set
POWER-BATTERY
switch A6S2 to
OFF
.
(n) Remove discharged batteries and reinstall
charged batteries (nominal -48.0 V dc) to the
appropriate terminals on TB2).
(o) Set
POWER-BATTERY
switch to
ON
.
(p) Momentarily depress (three to five seconds)
BATTERY RESET
switch.
(q) Verify transmitter turns on and is operating at
the intended carrier level and the intended
modulation depth.
(r) Remove
multimeter.
(s) Set
POWER-AC LINE
switch A6S1 to
ON
.
(t)
BATTERY-ALARM
lamp shall turn off and the
remote battery alarm control signal (ground)
shall be removed from TB3-14.
(u) Verify transmitter is operating at the intended
carrier level and the intended modulation depth.
5.3.21 TEST/ADJUSTMENT OF SIDE B:
Complete a functional test and if necessary adjust side
B
of the transmitter as follows:
(a) Set
SELECT MAIN TX
switch to
B
.
(b) Repeat paragraphs 5.3.2 through 5.3.20 using
reference designations and transmitter side
identification in parenthesis for modules that are
duplicated in sides
A
and
B
.
NOTE
SELECT MAIN TX
switch must be set to
B
when
instructed to set switches as tabulated for
Test
Settings
in table 4-1.
SPECIAL ADJUSTMENT PROCEDURES
5.4
Procedures referred to as special adjustment
procedures require test equipment that is not normally
available at transmitter sites. The adjustments have
been precisely set at the factory prior to shipment and
should not require further adjustment. The accuracy
of the settings will affect the accuracy of the
adjustment settings; therefore, they should not be
disturbed unless their accuracy is suspect and then
only if specified test equipment is available.
High voltages that may cause serious injury or death
are present inside the transmitter cabinet. Use
extreme caution when
ac
power is applied.
NOTE
When an adjustment procedure is for a module or
component that is duplicated for sides
A
and
B
, the
reference designation that is applicable to the side 'B'
module is shown in parenthesis (see note after
paragraph 5.3.3).
5.4.1
CURRENT
SHUNT
RESISTOR
ADJUSTMENT
(see figure SD-1): Adjust current
shunt resistor R1 (R4) as follows:
(a) Set switches, except
POWER-AC LINE
switch as
tabulated for
Test Settings
in table 4-1.
(b) Set
POWER-AC LINE
switch A6S1 to
OFF
.
(c) Remove left (right) side panel from transmitter
cabinet.
(d) Set
TEST-Volts/Current
switch to
DC
CURRENT-
SIDE A
(
B
).
(e) Set
O/P POWER
potentiometer A4A2R48
(A5A2R48) fully counter clockwise.
(f) Using a clip-on dc current meter, clip current
meter over wire going to current shunt resistor
R1-5 (R4-5).
