Icom I706MKTMG - Microphone (HM-103) Description

• 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 and 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 2345678
• HM-103 SCHEMATIC DIAGRAM
4700p
4700p
10µ
0.33µ
+
+
MICROPHONE
MIC
ELEMENT
2k
2.2k
470
DOWN UP
PTT
RECEIVE
TRANSMIT
MICROPHONE
CABLE
MICROPHONE PLUG
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Caution: DO NOT short pin 1 to ground as
this can damage the internal 8 V regulator.