KMC-35/36
CIRCUIT DESCRIPTION
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.
â� 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
C17 100p
Q1 DTC114EUA
C14 1000p
R1 10k Q3 DTA144EUA
J1 1 BLC 2 SB 3 GND 4 PTT 5 ME(MIC GND) 6 MIC 7 HK(HOOK) 8 DM *L1 L2
PTT SW R9 1.5k C6 1000p
