TM 11-5821-333-30
6-6. TEST ADAPTER. Continued
c. Rf Section. The rf section of the test adapter, as shown in the partial schematic diagram of figure 6-4, is
a series of rf cables, dividers, relays and attenuators. The path of signals is controlled by the relays K1 through
K3. The relays are shown in their inactive positions. When ground is applied to the negative control lead, the cur-
rent flow from +28V to GND activates the relay coil and the signal path switches to the alternate route. The nega-
tive control lead for each relay is grounded by the routing switches. The rf section provides:
l Rf signals into rt uut homing antenna connectors for calibrating rt homing function,
l A signal path between the reference rt and rt uut antenna connectors,
l Signal from a signal generator to the rt uut,
l Signals from the rt uut at connector J12 (RF DET) or samples of the signals for the test equipment.
d. Routing Switches. The routing switches are switches S1 through S6. They are 12 position switches with
five decks or layers each. They provide a method for routing a large number of control and communication sig-
nals between unit-under-test radios, reference radios, and test equipment. Switches S1 through S3 are mainly
for routing rt and rcu signals; S4 through S6 are for dra signals.
e. Test Lamps. These 10 lamps show the status of some of the important signals routed through the test
adapter. The signals monitored are listed in table 6–1. The +5 V supply for the test lamps is derived by U1, a volt-
age regulator, from the +28 V supply. The control circuits for the test lamps are mounted on the TEST LAMP cir-
cuit card assembly (CCA). All the test lamps may be turned on for maintenance checks with the LAMP TEST
switch, S16.
Table 6-1. Test Lamp Signals
LAMP #
SIGNAL(S) MONITORED
LAMP LIT WHEN SIGNAL IS
1
POWER ON/OFF from ref rcu
+28 V
POWER ON/OFF from rt uut
+28 V
2
T-ZERO-N from rcu uut
LOGIC O
XMODE CNTRL from dra uut
LOGIC O
3
RXMT A/D SEL from rt uut
LOGIC O
ON from PT/CT SWITCH
+6.75 V
4
POWER ON/OFF from rcu uut
+28 V
+28 V from TEST LED SWITCH
+28 V
5
PT/CT OUT from dra uut
LOGIC O
IFM PWR B OUT from rt uut
LOGIC O
6
RXMT CONT OUT (2) from rt uut
LOGIC O
LOOP TEST from dra uut
LOGIC O
LOOP TEST from rcu uut
LOGIC O
7
PTT from dra uut
LOGIC O
ECCM/SC from rt uut
LOGIC O
8
PTT OUT from dra uut
LOGIC O
HI LO BAND from rt uut
LOGIC O
9
IFM TR
LOGIC O
10
IFM PWR A OUT
LOGIC O
6-7
