TM 5-6675-318-14
Table 4-24. DIRECT/GENERAL SUPPORT TROUBLESHOOTING - Cont
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
12.
ERROR T, FAULTY ANTENNA SYSTEM.
Step 1.
Disconnect the antenna cable from the preamplifier. With the
receiver/processor in operation, check for -10 V through the
antenna cable.
( a ) I f v o l t a g e i s n o t p r e s e n t , p r o c e e d t o s t e p 2 .
( b ) I f v o l t a g e i s p r e s e n t , r e p l a c e t h e p r e a m p l i f i e r .
Step 2.
Remove the antenna cable from the receiver/processor and check for
c o n t i n u i t y .
( a ) I f c o n t i n u i t y e x i s t s , r e p l a c e t h e d u a l c h a n n e l r e c e i v e r b o a rd
(paragraph 4 - 20 . 3).
( b ) I f c o n t i n u i t y d o e s n o t e x i s t , r e p l a c e t h e a n t e n n a c a b l e .
13. ERROR U, EXCESSIVE VCO DRIFT IN
Replace dual channel
14. ERROR V, EXCESSIVE VCO DRIFT IN
Replace dual channel
15. NO DISPLAY.
150 MHz RECEIVER.
r e c e i v e r b o a r d ( p a r a g r a p h 4 - 2 0 . 3 ).
400 MHz RECEIVER.
r e c e i v e r b o a r d ( p a r a g r a p h 4 - 2 0 . 3 ).
Step 1.
Check for correct voltages at connector J13, pins 5 through 13 and
17 through 25, and ground at pins 1, 2, 3, 14, and 15.
4-197
