Circuit Description - Kenwood KMC-35 Service Manual

Hot Microphone Function
In the Hot microphone state, only microphones whose
PTT switch is pressed can send modulation signals in the
environment in which several microphones are connected to
the transceiver in parallel.
In the Normal microphone state, if the PTT switch on one
of the microphones is pressed, modulation signals are sent
from all microphones.
J1
1 BLC
2 SB
3 GND
4 PTT
5 ME(MIC GND)
6 MIC
7 HK(HOOK)
8 DM
E58-0475-05

CIRCUIT DESCRIPTION

*L1
L2
L3 R6 0
L4
L5
L6
L7
*L8
KMC-35/36
■ Circuit description
Hot microphone operation can be performed by cutting
the jumper (JP1).
If the jumper is not cut (Normal microphone state), bias
voltage is always applied to the microphone element (Q3 is
always ON) and if the microphone mute of the transceiver to
which the KMC-35/36 is connected is released, modulation
signals can be sent even when the microphone PTT switch is
not pressed.
If the jumper is cut (Hot microphone state), bias voltage is
applied to the microphone element only when the PTT switch
is pressed (Q3 turns ON only when the PTT SW is pressed),
and modulation signals cannot be sent when the microphone
PTT switch is not pressed.
5V
Q1
DTC114EUA
R1 10k
Q2
DTC144EUA
10u 16
R8
1k
Q3
DTA144EUA
C7
1u 16
C9
MIC
T91-0538-05
3