Kenwood TH-42A - Manual (Page 64)

CONNECTING OPTIONAL EQUIPMENT
When connecting an external speaker, an external
microphone, or other equipment such as a TNC for
packet radio to the speaker or microphone jack, refer to
the diagram below:
Speaker
SP ------------------V
1
I
Ground
£
0>
O)
O-
3V
MIC
PTT
3V
0 2.5
plug
Ul
MIC
0
PTT
03.5
plug
r?
}
VJ
Note 1
Note 2 lO^iF
a c
o
j :
Q. O
u
E
c
Q
X
LU
Note 7; Voltage is developed across the 220 n resistor in the
3 V Une. (When 2 mA flows, about 2.5 V is developed.)
Note 2: A 10 fxF capacitor is not required in the following
cases. Make direct connections.
• When the other equipment has DC blocking capacitors.
• When a two-terminal condenser microphone is used.
CAUTION; To connect an external 24 V power source via a DC-DC
converter, only use a PG-3J Cigarette Lighter cable.
DC-DC converter
2 4 V *
Cigarette lighter socket
DC-DC converter
s
\ \ |\
K m 24V-^* J2V^JHs PG-3J
Cigarette lighter socket
CAUTION: NEVER use a PG-2W DC cable in this situation; doing
so may cause a fire.
2 4 V *
PG-2W
I 1Ti
DC-DC converter
62