Microphone, Microphone connector, Caution – Icom IC-756 User Manual
Page 11: Hm-36), Hm-36 schematic diagram

• MICROPHONE CONNECTOR
(Front panel view)
CAUTION:
DO NOT short pin 2 to ground as this
can damage the internal 8 V regulator.
y
GND (PTT ground)
t
PTT
r
Main readout squelch switch
q
Microphone input
w
+8 V DC output
e
Frequency up/down
u
GND
(Microphone ground)
i
Main readout AF output
(varies with [AF]/[BAL])
8
1
PANEL DESCRIPTION
■
Microphone
(HM-36)
q
UP/DOWN SWITCHES [UP]/[DN]
Change the selected readout frequency or memory
channel.
- Continuous pushing changes the frequency or memory
channel number continuously.
- While pushing [XFC], the transmit readout frequency
can be controlled while in spilt frequency operation.
- The [UP]/[DN] switch can simulate a key paddle. Preset
in the keyer set mode. (p. 35)
w
PTT SWITCH
Push and hold to transmit; release to receive.
q
w
+
+
q
w
e
r
t
y
u
i
4700p
4700p
10
µ
0.33
µ
MICROPHONE
MIC
ELEMENT
2k
470
DOWN
UP
PTT
RECEIVE
TRANSMIT
MICROPHONE CABLE
MICROPHONE PLUG
• HM-36 SCHEMATIC DIAGRAM
PIN NO.
FUNCTION
DESCRIPTION
w
+8 V DC output
Max. 10 mA
e
Frequency up
Ground
Frequency down
Ground through 470
Ω
r
Squelch open
“LOW” level
Squelch closed
“HIGH” level