Hytera MD78X Service Manual

Interface Definition
VHF (136MHz
–
174MHz)
38
Pin
No.
Name Type
Signal Electrical
Performance
Description
4 SWB+ Power output
Power
supply :13.2V±15%;
output current≤1 A
Power output:
13.2 V;
output current: ≤1 A
5 External Alarm
Analog voltage
output
13 V alarm output
Programmable output pin
(“External Horn & Lights”
feature by default,
programmable via CPS).
6 Power Ground
Power supply
(grounding)
/ /
7 TX Audio
Analog signal
input
Vrms=80mV±10%@1
k
Hz 60% system max.
deviation
This pin is used for signal
input of external MIC. The
audio path is valid when the
external Mic PTT is held
down.
8 RX Audio
Analog signal
output
Load impedance>1 kΩ
Vrms=300mV±10%@1
kHz
60% system max.
deviation
Default output is 300 mV.
The output signal amplitude
can be changed by
modifying the “Analog RX
Gain” value via CPS.
9 SPK- Analog output
It forms differential output
together with SPK+. Max
power output: 10 W(R=8
Ω)
External speaker output-
10 D+ USB data cable+ USB data USB data cable+
11 USB_GROUND Ground cable / /
12
GP5_2
(Monitor)
GPIO 5V TTL
GPIO. Programmable via
CPS; Monitor feature by
default.
13 ACC_IO2 Digital input 5V TTL
Accessory identification
inter
face; high level by

Hytera MD78X Specifications

General

Brand	Hytera
Model	MD78X
Category	Radio
Language	English