PBL 3766
TIPX 27/21
TIP
I
L
+
R
F
+
Z
L
RHP
2
1
1
HPT
-
Z
TR
20/15
19/14 VTX
V
TR
C
+
HP
HPR
21/16
+
RHP
2
+
E
-
V
TX
L
-
R
F
I
-
L
-
Z
RING
RINGX 28/22
T
Z
RX
16/12 RSN
/1000
+
V
RX
I
L
-
PBL 3766
Figure 8. Simplified ac transmission circuit.
R
FB
R
TX
-
VTX
19/14
+
V
T
PBL
3766
Z
Z
B
T
Combination
CODEC/Filter
Z
RX
V
RX
16/12
RSN
Figure 9. Hybrid function.
I
TIPX 27/21
Lo
V
Lo
I
Lo
1
1
R
V
+ V /2
Bat
Lo
R
= 20 kohms
Lo
+
1
V
I
R
Lo
Lo
-
/1000
V
/2
Bat
I
I
Lo
Lo
V
Lo
RINGX 28/22
PBL 3766
Figure 10. Longitudinal feedback loop.
4-11