Microphone Connector Information - Icom IC-7800 Instruction Manual

2
INSTALLATION AND CONNECTIONS
■ Microphones (options) (continued)
D HM-36
q

■ Microphone connector information

(Front panel view)
i Main readout AF output
q Microphone input
w +8 V DC output
e Frequency up/down
r Main readout squelch switch
• EXTERNAL KEYPAD connection
S4 S3 S2
(T4/M4/ (T3/M3/ (T2/M2/
PT4/RT4) PT3/RT3) PT2/RT2)
4.7 kΩ 2.2 kΩ 1.5 kΩ
±5% ±5% ±5%
w
(varies with [AF])
u GND
(Microphone ground)
y GND (PTT ground)
t PTT
To pin y
S1
(T1/M1/
PT1/RT1)
To pin e
Microphone
1.5 kΩ
±5%
connector
q PTT SWITCH
Hold down to transmit; release to receive.
w UP/DOWN SWITCHES [UP]/[DN]
Change the selected readout frequency or memory
channel.
• Holding down continuously changes the frequency or
memory channel number.
• While holding down [XFC], the transmit readout frequen-
cy can be controlled while in the split frequency mode.
• The [UP]/[DN] switch can simulate a key paddle. Preset
in the keyer set mode. (p. 4-12)
[MIC]
FUNCTION
Pin No.
+8 V DC output
w
Frequency up
e
Frequency down
Squelch open
r
Squelch closed
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 op-
eration. Use caution when using a non-Icom
microphone.
2-10
DESCRIPTION
Max. 10 mA
Ground
Ground through 470 Ω
"Low" level
"High" level