11
• MICROPHONE CONNECTOR
(Front view)
y
GND (PTT ground)
t
PTT
r
Squelch switch
q
Microphone input
w
+8 V DC output
e
Frequency up/down
i
AF output
(varies with [AF])
u
GND
(Microphone ground)
[MIC]
PIN NO.
FUNCTION
DESCRIPTION
w
+8 V DC output
Max. 10 mA
e
Frequency up
Ground
Frequency down
Ground through 470
˘
r
Squelch open
“LOW” level
Squelch close
“HIGH” level
CAUTION:
DO NOT
short pin 2 to ground as
this can damage the internal 8 V regulator. DC
voltage is applied to pin 1 for microphone opera-
tion. Use caution when using a non-Icom micro-
phone.
• HM-36 SCHEMATIC DIAGRAM
+
q
w
e
r
t
y
u
i
4700pF
0.33µF
MICROPHONE
MIC
ELEMENT
2k
ø
470
ø
DOWN
UP
PTT
RECEIVE
TRANSMIT
MICROPHONE CABLE MICROPHONE PLUG
1k
ø
+
10µF
q
UP/DOWN SWITCHES [UP]/[DN]
Change the selected readout frequency or memory
channel.
• Pushing the switch continuously changes the frequency
or memory channel number continuously.
• The [UP]/[DN] switch can simulate a key paddle. Select
in set mode (U/D KEY; Mic Up/Down Keyer). (p. 80)
• While pushing and holding
RIT
*, push the [UP]/[DN]
switch to control the transmit readout frequency while
in spilt frequency operation.
* Available only when the XFC (transmit frequency
check) function is turned ON. (p. 76)
w
PTT SWITCH
Push and hold to transmit; release to receive.
e
PTT LOCK SWITCH (SM-20 only)
Push to lock the PTT switch to the transmission
codition.
q
w
q
w
e
■
Microphones
D
HM-36
D
SM-20
(Option)
1
PANEL DESCRIPTION