Microphone (hm-103), Technical information – Icom I706MKTMG User Manual
Page 11
• MICROPHONE CONNECTOR
8
1
PANEL DESCRIPTION
■ Microphone (HM-103)
➊
UP/DOWN SWITCHES [UP]/[DN]
Change the operating frequency.
• Push and hold to change the frequency continuously.
• Tuning step is 50 Hz when no TS indicator appears.
➋
LOCK SWITCH [LOCK]
Locks the [UP]/[DN] switches.
➌
PTT SWITCH [PTT]
Push an
d hold to transmit; release to receive.
DN
UP
LOCK
OFF
ON
➊
➋
➌
TECHNICAL INFORMATION
PIN NO.
FUNCTION
DESCRIPTION
1
+8 V DC output
Max. 10 mA
2
Frequency up
Ground
Frequency down
Ground through 470
Ω
8
Squelch open
“LOW” level
Squelch closed
“HIGH” level
➃
PTT
➅
Microphone input
➁
Frequency up/down
➆
GND
➀
+8 V DC output
➇
Squelch switch
➄
GND (microphone ground)
➂
AF output
Rear panel view
1 2345 678
• HM-103 SCHEMATIC DIAGRAM
4700p
4700p
10
µ
0.33
µ
+
+
MICROPHONE
MIC
ELEMENT
2k
2.2k
470
DOWN
UP
PTT RECEIVE
TRANSMIT
MICROPHONE
CABLE
MICROPHONE PLUG
1 2345678
Caution:
DO NOT short pin 1 to ground as
this can damage the internal 8 V regulator.