Operating instructions

BK RADIO Specifications are subject to change without notice. Page 1-1
SECTION I
GENERAL INFORMATION
1.1 INTRODUCTION
This manual contains information about the physical, mechanical, and electrical characteristics of
the BK Radio DMH APCO Project 25 digital radios.
1.2 DESCRIPTION
The DMH APCO Project 25 digital radios are self-contained VHF FM Radios covering the
frequency range of 136MHz to 174MHz. The radios are multi-channel and digitally synthesized
using a single crystal for frequency control. All models incorporate an EEPROM for the storage of
data such as channel frequencies, channel guards, channel labels, and digital data. The DMH
features an alphanumeric eight-character vacuum fluorescent display, allowing the channels to be
named for easy user recognition.
An arrow on the vacuum fluorescent display points to each front-mounted push button that is
active. The five push buttons can be programmed with the following functions:
Standard Functions Optional Functions
MON
Monitor Squelch Noise
TA
Repeater Talk Around
GSC
Group Scan
SCN
Channel Scan
CG
Channel Disable
SQL
Squelch Adjust
PRI
Priority Scan
HOM
Home Channel
SEC
Transmit Secure Mode
PA
Public Address
SPK
Remote Speaker
ACC
Accessory 1
GRP
Group Select
NXT
Next Scan Channel
ACC
Accessory 2
TXD
Transmit Digital Mode
LPW
Low Power Select
ACC
Accessory 3
The microphone connector provides an RS-232 interface for control by a keypad microphone,
and for dealer programming of alphanumeric labels, push button functions, channel frequencies,
and Dual Tone Multiple Frequency/Automatic Numeric Identifier (DTMF/ANI) encode information.
BK RADIO
SCN PRI GRP SQLMON
VOL
OFF -
CH
DMH
Transmit Indicator
Priority Indicator
Busy Channel Light
Function Button
On/Off Indicators
Display Dimming Sensor
Function Buttons
Channel Selector
Knob
On/Off
Volume Knob
Microphone
Connector
Figure 1-1 CONTROLS