1 4. H ET E R O DY N E C R YSTA L OSC I L LATO R
A LI G N M E NT
T h e heterodyne crystal oscillation inj ection may be
checked in the following manner. Connect the VTVM
RF probe to the local oscillator test point. Inj ection
is normal if the inj ection voltage measures 0.3 Volt
RMS on all bands.
If not. alignment is required. Set the BAND sw itch
at 1 0 0. TC2 3 at 1/3 capacitance position. and adj ust
Tll l for 0.3 Volt RMS read ing on VTVM. Then adjust
TC2 3 . TC22. TC2 1 ....... TC16 and TC26 for each of
the band to read 0.3 Volt RMS on VTVM.
B A N D
No.
T U N I N G C A P A C ITOR
1 60
X l l
C 1 2 7
250PF
TC26
80
x
1
C45
300PF
TC 1 6
40
x
2
C46
1 50PF
TC 1 7
20
x
3
C47
50PF
T C 1 8
1 5
x
4
TC 1 9
l O A
x
5
TC20
l O B
x
6
T C 2 1
l O C
x
7
TC22
1 0 0
x
8
T C 23
A U X
x
9
TC24
wwv
X l O
C 4 8
l OOPF
TC25
X 1 ( I OC )
X s ( I O D )
X g ( A U X )
X 1 o ( W W V )
X 1 1 ( 1 6 0 )
I
(
8 Q)
X 2 ( 4 0 )
X 3 ( 2 0 )
X 4 ( 1 5 )
X c ( l OB )
C R Y S T A L F R E Q U E N C Y
---- --
7 . 5 2 M H z
9 . 5 2 M H z
1 3 . 0 2 M H z
2 0 . 0 2 M H z
2 7 . 0 2 M H z
3 4 . 0 2 M H z
3 4 . 5 2 M H z
3 5 . 0 2 M H z
3 5 . 5 2 M H z
-·------- -
1 6 . 0 2 M H z
LOCAL OSCILLATOR TUNING CHART
$ �
"'
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....
....
"'
0
'"'
"'
�
"'
"'
0
..,
'°
,..:
"'
"'
0
..,
,.;
ai
0
�
..
L24
Qs 25C372Y
I
T l 1 1
C l 5
L 3
CI G
GV
LOCAL OSCILLATOR TUNING CIRCUIT
-
2 8 -
