ICOM IC-703 Manuale Utente
10
1
PANEL DESCRIPTION
• MICROPHONE CONNECTOR
■Microphone (HM-103)
q
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.
• Tuning step is 50 Hz when no TS indicator appears.
w
LOCK SWITCH [LOCK]
Locks the [UP]/[DN] switches.
e
PTT SWITCH [PTT]
Push and hold to transmit; release to receive.
DN
UP
LOCK
OFF
ON
q
w
e
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
r PTT
y Microphone input
w Frequency up/down
u GND
q +8 V DC output
i Squelch switch
t GND (Microphone ground)
e AF output
Rear panel view
1
2
3
4
5
6
7
8
• HM-103 SCHEMATIC DIAGRAM
4700p
4700p
10
µ
0.33
µ
+
+
MICROPHONE
MIC
ELEMENT
ELEMENT
2k
2.2k
470
DOWN
LOCK
UP
PTT
RECEIVE
TRANSMIT
TRANSMIT
MICROPHONE
CABLE
CABLE
MICROPHONE PLUG
1 2345678
CAUTION:
DO NOT short pin 1 to ground as
this can damage the internal 8 V regulator.
1