KMC-35/36
3
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.
CIRCUIT DESCRIPTION
Q1
DTC114EUA
R1 10k
5V
R2
10k
R3
10k
R5
10k
R4
3.9k
R7
3.9k
R8
1k
R9
1.5k
R10
0
R6
0
*C5
C6
1000p
C12
1000p
C13
1000p
C14
1000p
C18
1000p
C17
100p
C10
0.068u
C7
1u 16
C9
10u 16
*L1
L2
L3
L4
L5
L6
L7
*L8
*C16
*C19
*C15
MIC
T91-0538-05
Q2
DTC144EUA
Q3
DTA144EUA
S70-0499-08
J1
E58-0475-05
1 BLC
2 SB
3 GND
4 PTT
5 ME(MIC GND)
6 MIC
7 HK(HOOK)
8 DM
C20
1000p
C11
470p
S1
PTT SW
JP1
■
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.
