M A I N T E N A N C E P R . V C T I C E S
D E T A I L S T E P S / W O R K I T E M S KEY ITEMS
Adjust the tuning cores of local oscillator
c o i l L I O , m i x e r c o i l L 7 a n d r - f c o i l L 4
(in this order), for maximum indication on
tuning meter.
(e)
Adjust output of signal generator as
f o u n d n e c e s s a r y t o m a i n t a i n m i d - s c a l e
reading on tuning meter.
(f)
Adjust the si g n a l g e n e r a t o r to 4 00 kc.
unmodulated.
(g)
Adjust the receiver tuning knob for a
frequency of 400 kc.
(h) A d j u s t t r i m m e r c a p a c i t o r s C 3 9 , C 2 4 a n d
C22 (in this order), for maximum indication
on the tuning meter.
M a i n t a i n t u n i n g m e t e r a t m i d - s c a l e
indication during adjustments, and
repeat steps (b) through (h) until no
fu r th e r im p ro v e m e n t c a n b e o bt a in o b ¬
tained.
In each case, always make the last ad¬
justment with the trimmer capacitor.
(i)
Repeat steps (b) through (h) as follows on
b a n d s 2 a n d 3 :
B a n d 2 : 5 0 0 k c - A d j u s t L l l , L 8 a n d L 5
800 k c -Adju s t C41, C 26 and C 1 7
B a n d 3 : 1 0 0 0 k c - A d j u s t L 1 2 , L 9 a n d L 6
1600 kc -Adju s t C 4 3 , C 2 8 a nd C19
(3) Loop Stage Alignment
(a ) S e t t he r e ce i ve r f un c ti o n sw i tc h t o t h e A DF
position.
(b ) S e t t h e rec e i ver b a nd s e l ec t o r sw i t c h t o t he
190-440 position.
i
s
NOTE
Servo motor must not rotate while aligning loop stages.
Do not attempt to retard motor by holding or clamping.
The recommended method of stopping motor is as follows:
Jl
Jl
2
7
16 O'
SERVO
AMPLIFIER-INDICATOR
ADF
RECEIVER
0
AC
0.68
9.IK
VTVM
(During loop alignment, switch must be in position 1)
(c) Adjust the signal generator to 200 kc, un¬
m o d u l a t e d a n d f o r a fi e l d s t r e n g t h o f 2 0 0
microvolts-per-meter.
Manually rotate fixed loop through 90
degrees.
(
April 1965
Page 104
To Next Page
Loading...
General