(1) Group case power. Interface adapter 1A1A1
interconnection of the interface adapter unit into the test
provides a primary ac power output 115 vac at 60 Hz or
Troubleshooting procedures for group 1
400 Hz (at 30 amps) for while testing the IFF set.
components are contained in b through e below.
(2) Power. This function provides primary power of
b. Antenna Pedestal Mounting. Isolation of trouble to
115 vac at 60 Hz or 400 Hz for internal operation of
pedestal mount 1A7 is made by visual inspection and the
interface adapter unit 1A1A1.
corrective action to be taken is based upon the trouble
(3) Azimuth data. Simulated radar antenna rotation
data is provided for testing the IFF set antenna circuits.
c. Antenna Weight Simulation. Trouble shooting of
(4) Enables. This function provides ground enabling
inertial antenna load 1A6 is not required. Therefore
functions in the IFF set.
isolation of trouble in this assembly is not required.
(5) Monitoring. Front panel test points are available
d. Interface of IFF Set. The interface adapter an unit
for monitoring of the IFF set video and adjusted iff
provides four basic testing functions. It also provides
monitoring capability of IFF set video signals, adjusted
azimuth signals, and interconnections. The four basic
the test setup is accomplished by cables and rear panel
functions are group case power, interface adapter unit
connectors on interface adapter unit 1A1A1. The cables
power, azimuth data, and enables. The monitoring of
are provided in both group 1 and group 2, however, the
video and adjusted azimuth signals is accomplished at
larger number of cables is in group 1. Because the
13 of front panel test points. When isolation of trouble in
functional indication of trouble in any of these
the IFF set has been functionally identified, a
determination can be made if group 1 is defective by
IFF or radar set, conventional troubleshooting
using the descriptions of group 1 functions below.
procedures cannot be accomplished.
When interface adapter unit 1A1A1 is
Before replacing any component listed in the
connected to a primary power source and the
corrective action column, make certain that
GROUP CASE POWER controls are set to
the suspect component has malfunctioned
ON, interlock switches 1A1A1S14 and
and its associated wiring is not at fault.
1A1A1S15 do not interrupt the group case
e. General Support Troubleshooting Procedures,
Interface Adapter Unit 1A1A1.
1 Set GROUP CASE POWER 60-Hz
circuit breaker to ON and GROUP
replace if defective.
CASE POWER SELECT switch
b. Defective GROUP CASE POWER
b. Check GROUP CASE POWER
to 60 Hz. GROUP CASE POWER
SELECT switch 1A1A1S1.
SELECT switch 1A1A1S1 and
ON lamp and 60-Hz circuit breaker
replace if defective.
c. Defective 60-Hz circuit breaker c.
do not remain on.
Check 60-Hz circuit breaker 1A1A1-
CB1 and replace if defective.
a. Same as step 1 above
a. Same as step 1 above.
2 Set GROUP CASE POWER 400-
b. Same as step 1 above
b. Same as step 1 above.
Hz circuit breaker to ON and
c. Defective 400-Hz circuit breaker
c. Check 400-Hz circuit
GROUP CASE POWER SELECT
switch to 400 Hz. GROUP CASE
1A1A1CB2 and replace if de-
POWER ON lamp and 400-Hz
circuit breaker do not remain on.
CAUTION: Before connecting test equipment, place all GROUP CASE POWER and POWER
switches to their OFF positions. Insert insulated extender pins (para 6-2e) over connector pins
which will be monitored. Connect test equipment and set the GROUP CASE POWER and
POWER switches to the applicable positions.
a. Defective SYNC/RSLVR SEL
a. Check SYNC/RSLVR/SEL switch
3 SYNC/RSLVR SEL switch: RSLVR
AZIMUTH DATA-FREQ SELECT
1A1A1S6 and replace if defective.
b. Defective ANT ROTATION switch
b. Check ANT ROTATION switch
switch: 4000 026 vac at 4 kHz
is not available between 1A1A1J10-R
1A1A1S3 and replace if defective.
Change 1 6-7