CIRCUIT DESCRIPTION
1 3 . Band information generatio n circuit (in the RF
unit)
B a n d information from the control u n it i s sent t o connector
1 5 of the RF u nit. Band information sig nals BO to B3 form
a BCD code in which BO corresponds to LSB . 04D
(M74LS 1 4 5P) is used to convert d ata from BCD to DEC, and
it generates control sig nals for ten of the 1 1 bands . Control
signals for the remaining band ( 2 5 . 5 MHz to 30 MHz) are
generated in the AND circuit consisting of D 57, D 58, and
046. These contorl sig nals go through the current buffer con
sisting of 04 1 to 04 5 (M5456 1 P and 2SA 56 2Y), and are
OR' ed by diodes, as req uired, and sent to AT u nit, filter u n it,
CO, and ANT BPF, as shown in Fig u re 2 1 .
8 3 8 2
8 1
80
8 V
4
3
2
r
R l 8 3
M S B
LSB
12
"
14
rs
0 40 M 74 L S 1 4 5 P
BCD - DEC
2
3
4
5
6
7
9
ro
r r
"'
"'
.
"'
w
I
.:
I
w
I
N
.
7
6
5
4
3
2
r
04 1
M 5 4 5 6 1 P
B
u f f
B a n d information 7 8 0 0 P B o - 3 , B 3 B 2 B 1 B o
3 0 k H z
-
0 . 5 M H z
0 . 5 M H z
-
1 . 6 M H z
1 . 6 M H z
-
2 . 5 M H z
2 . 5 M H z
-
4M H z
4 M H z
-
6 M H z
6 M H z
-
7 . 5 M H z
7 . 5 M H z
-
1 0 . 5 M H z
1 0 . 5 M H z
-
1 4 . 5 M H z
1 4 . 5 M H z
-
2 2 M H z
2 2 M H z
-
2 5 . 5 M H z
2 5 . 5 M H z
-
3 0 M H z
Table 1 3
14V
2
2 8 T
125. 5 - 30 1
24T ( 2 2 "' 25.5)
I
"'
To AT u
2 1T
( 14,5 ..... 2 2 )
1 4T
( 10.5- 14.5)
IOT
I
7.5 ,.... JO . S J
7T
1 6
...... 7. 5 )
?
• 7
042 043
044
ro
0
0
0
r r
12
"
14
15
16
G)
D 6 1
D 6 5
r
28F
2
2 I F
3
14 F
4
7F
D62
5
4F
6
2F
O I B
I
1 22 - 30)
114.5- 22 1
( 7.5 - 14.51
To
Fi
lie r u
1 4 ...... 7. 5 1
(2.5"" 4 J
( 1.6 - 2.5 )
2 1
{
67.05 - 75.05
122 ...., 301
22
{
59.55 ..... 67.05
( 14.5-22)
:
I
{
52.55
_
59.ss
{7,5 - 14.5 )
.
w
I
N
.
To
"'
.:
I
w
R F U B P F
I
I
I
I
L
_ _ .....J
D67
020
-024
{
45.05 - 52.55
(0 "-' 7. 5 1
VCO
SW
VCO
Fig . 2 1 Band information generation circuit
TS-440S
0 0 0 0
0 0 0 1
0 0 1 0
0 0 1 1
0 1 0 0
0 1 0 1
0 1 1 0
0 1 1 1
1 0 0 0
1 0 0 1
1 0 1 0
2 3
