Zeromic STHD-F1, Instruction Manual, Page: 37 / 40

The connection method of
earphone mike and various PTT button
items Type remarks
Operating
voltage range
15.0V ～ 3.7V
7.5V standard (GL2000)
Consumption current
Below 20mA
7.5V standard (GL2000)
Connection of
two-way radio
7cable /8 cable connection
(1) power input, (2, 3) speaker BTL input,
(4) GND, (5, 6) microphone differential output,
(7) PTT, (8) option output power
Speaker input
impedance
400 Ω (receiving)/
above 10k Ω (emitting)
Impedance can be adjusted
Speaker input
signal level
1Vrms /Maximum input 3VP − P
Volume can be adjusted
Microphone output
impedance
Below 2k Ω (emitting)/above
10k Ω (receiving)
Impedance can be adjusted
Microphone output
signal level
-30dBV
Adjusting range
：
-25dBV
～
-60dBV
PTT signal /
optional mode
RON<0.5 Ω / ID<100mA / VD<10V Independent loop system
Control method Microprocessor control
Function buttons
can be changed
Specification of Bluetooth version
items Type remarks
Bluetooth basic
specification
Bluetooth 4.1 Class 2 is matched
BLE(Bluetooth Low Energy ）
function is contained
Bluetooth
matches with
Bluetooth HSP / HFP / SPP
Android end/ i-OS (iPhone/iPad)
PTT application
matches with
Bluetooth SPP and BLE method PTT requires custom applications
Power mode
Built in lithium battery 3.7V/250mAH
Micro USB terminal charge
Charging time Less than 2 hour Full recharge
Continuous
action time
More than 12 hour
In full recharge
35