Aeroflex ATC-1400A-2 - Page 35

MAI NTENANCE MANUAL
ATC-1400A-2
2-2-2
Page 3 5
Subj e c t to E x p o rt Con t r o l, s e e C o ver P a g e fo r d e tail s . F e b 2/ 0 9
STEP PROCEDURE
21. Ve r i f y de l a y time o f 4 2 0.8 µs ( 1 2 µs ) be t w e e n P
1
of Du a l P uls e G e n e rat o r a nd
P
1
of e c h o re p l y , on O s c i llos c o p e. A d j ust R 4 4 2 (Ec h o D e lay A d j ust ) ( 2-2- 2 ,
Figu r e 2 5) a s n e ede d f o r pr o p e r de l a y time.
22. Set T O / T A C / TD Switc h t o TO . C o n n ect Os c i l losc o p e Chan n e l B to R - N A V
Connec t o r (J9 ) .
23. Ve r i f y a p u l se s p a c ing o f 50. 0 µs (±0.2 5 µs) o n Osci l l o sco p e . Ad j u s t R92 5 7
(X Cha n n e l R NAV A d j u st) ( 2 - 2 -2, F i g u re 2 6 ) a s ne e d e d for p r o per p u l s e
spa c i n g.
24. Us i n g Osci l l o sco p e , ve r i f y P
1
and P
2
pul s e w i dth s a re 7 µs ( ±1 . 0 µs ).
25. Set FR E Q/ F U N C T I ON SELEC T T h u m b w h eels t o 1 09 0 M H z Y a nd Du a l Pul s e
Generat o r o utpu t f o r 36 µs s p a ci n g .
26. Ve r i f y a p u l se s p a c ing o f 56. 0 µs (±0.2 5 µs) o n Osci l l o sco p e . Ad j u s t R92 5 6
Y Chan n e l R NAV Ad j u s t ) (2- 2 - 2 , Figu r e 26) a s nee d e d for p r o per p u l se s p a cing .
27. Us i n g Osci l l o sco p e , ve r i f y P
1
and P
2
pul s e w i dth s a r e 7 µs ( ±1 . 0 µs).
28. Dis c o n n ect D u a l Pul s e G e n era t o r fro m A T C - 1 4 00A- 2 . Conn e c t Freq u e n cy
Counte r t o GEN Conn e c t o r.
29. Set ID E N T T O N E / OFF/CODE Sw i t c h t o TONE. V e r i fy f r e quen c y dis p l a yed i s
2700 H z (±0.54 H z ) .
NOTE: Fr e q u enc y C o u nte r r e ado u t i s do u b l e IDE N T p u lse r a t e, s o i t is
nec e s s ary t o div i d e by 2 t o v e r i fy a c c ura c y .
30. Dis c o n nec t F req u e n cy C o u n ter a n d co n n e ct Os c i l los c o pe t o G E N C o n nec t o r.
31. Set EQU A L I Z E R / OFF Swi t c h to EQUALIZER.
32. Ve r i f y eq u a l ize r p u lse s p acin g b etwee n i nte r r o gati o n pul s e P
1
and r e ply p u lse
P
1
is 1 0 0 µs (±10 µs).
33. Set PRF / S Q T R O N / O F F S witc h t o ON, IDENT T ON E / O F F / C O D E S witch t o OF F ,
PRF/SQTR T h u m b w h e els t o 270 0 a n d EQUALIZ E R / O F F S witch t o OFF.
34. Dis c o n nec t O s c i llo s c o pe f r o m GEN Connec t o r . Co n n e ct F r e q uen c y Count e r to
GEN Connec t o r .
35. Wi t h O s c ill o s c ope P r o be, mo n i t o r T P 4 0 8 a n d a djus t R 4 5 1 ( 2 - 2 - 2, F i g u re 2 5 ) as
need e d f or 6 0 µs ( ±1 0 µs ) lo w t i m e .
36. Obse r v e Fr e q u ency C o u nte r a n d t a k e ave r a g e of r a ndom sq u i t ter f r e quen c y .
Divid e b y 2, a n d ve r i f y s q u i tte r f r equ e n c y is 2 7 00 Hz ( ±29 H z ) .
37. Set PRF / S Q T R O N / O F F S witc h t o OFF, P RF / S Q T R T humbwhee l s t o 0 0 1 0 and
SELF-IN T E R R / O F F Switc h t o S E L F -INTERR.
38. Ste p P R F /SQTR Th u mb w h e e l s fr o m 1 0 to 5 9 9 9 Hz. V e r i fy PR F / S Q T R
Thu mbwh e e l s t r a c k wit h d isp l a y on f r equ e n c y c o u n ter .
NOTE: Fr e q u enc y C o u nter r e a dou t i s dou b l e PRF/ S Q T R T h umbwheel s e ttin g ,
so i t i s n e c e ssa r y to d i v ide b y 2 t o v erif y a ccu r a c y.
39. Rec o n n ect 5 0 Ω Termina t i o n to E X T E RNAL RF Con n e c t or (J 2 2 ) .
40. Set POW E R S w i t ch t o O F F .
41. Dis c o n nec t t e st e q u ipment .