SECTION III OPERATION 3.1 INTRODUCTION This section contains information concerning the operation procedures for the BK Radio DMH APCO Project 25 digital mobile radios. To meet backwards compatibility as defined by the APCO Project 25 standard, the DMH digital mobile radio provides users the ability to interoperate with narrow or wide band analog channels as well as digital systems. Please take a moment to read the information in this manual so you can get optimum performance from your new radio. 3.1.
Operation 3.2.1 DMH Series VHF Radio RF ENERGY EXPOSURE AWARENESS AND CONTROL INFORMATION, AND OPERATIONAL INSTRUCTIONS FOR FCC OCCUPATIONAL USE REQUIREMENTS BEFORE USING YOUR MOBILE 2-WAY RADIO, READ THE INFORMATION BELOW WHICH CONTAINS IMPORTANT OPERATING INSTRUCTIONS FOR SAFE USAGE AND RF ENERGY AWARENESS AND CONTROL INFORMATION FOR COMPLIANCE WITH RF ENERGY EXPOSURE LIMITS IN APPLICABLE NATIONAL AND INTERNATIONAL STANDARDS.
Operation 3.2.3 DMH Series VHF Radio COMPLIANCE WITH RF EXPOSURE STANDARDS Your BK Radio 2-way radio is designed and tested to comply with a number of national and international standards and guidelines (listed below) for human exposure to radio frequency electromagnetic energy. This radio complies with the IEEE and ICNIRP exposure limits for occupational/controlled RF exposure environment at operating duty factors of up to 50% talk50% listen and is authorized by the FCC for occupational use only.
Operation DMH Series VHF Radio installed (according to installation instructions) externally-mounted antenna to satisfy the RF exposure requirements in the standards listed above. CONTACT INFORMATION For additional information on exposure requirements or other information, visit website http://www.relm.com. 3.3 3.4 SAFETY PRECAUTIONS • Do not operate the transmitter in close proximity to blasting caps. • Do not operate the radio in an explosive atmosphere (petroleum fuels, solvents, dust, etc.
Operation 3.5 DMH Series VHF Radio BASIC OPERATION 3.5.1 RECEIVE Turn power on by pushing and releasing the Volume knob. The radio will beep, indicating that it has passed its self test and is operational. Set volume by pressing the [MON] button to hear squelch noise. Turn the Volume knob to set a comfortable volume level. Press the [MON] button again to stop squelch noise. Select a channel group (if applicable) by pressing the [GRP] button and turning the Channel Selector knob.
Operation 3.6.2 DMH Series VHF Radio APCO PROJECT 25 SQUELCH CONTROL Network Access Codes (NACs) provide the digital equivalent of analog sub-audible signaling (CTCSS/CDCSS) allowing a group of radios to be selectively called within a system. Users in the same area (using the same NAC) can be further divided into Talk Groups, with each group having its own Talk Group ID (TGID). Group Calls are made by designating both the users’ NAC and TGID. Each radio also has an individual P25 unit ID.
Operation DMH Series VHF Radio Select a channel by turning the Channel Selector knob. Press the [CG] button to disable or enable Channel Guard operation on analog channels. An arrow on the display points to the [CG] button when Channel Guard is disabled. When Channel Guard is enabled, a message is heard only when the proper Channel Guard is received. 3.6.
Operation DMH Series VHF Radio Talkback Scan, the RTX channel and receive annunciators will be displayed for the duration of the timer. The talkback timer can be cleared by making the held channel invalid. For instance, if a scan channel is being held, turn scan off. 3.8 PROGRAMMABLE PUSH BUTTONS/MICROPHONE FCN KEY FUNCTION MENU When the radio is installed, labels are placed on the front push buttons to indicate their functions.
Operation DMH Series VHF Radio 3. The keypad will be automatically unlocked when Unit-To-Unit Mode is entered by pressing PTT to respond to a Unit-To-Unit call, when Unit-To-Unit callback is enabled. The keypad will be re-locked when Unit-To-Unit Mode is exited. Push button controls are described as follows: MON Monitor Squelch Noise Press the [MON] button to start or stop monitoring squelch noise. This allows you to set a comfortable volume level.
Operation DMH Series VHF Radio TA Repeater Talk Around Press the [TA] button to turn Repeater Talk Around on or off. When TA is on, the radio transmits on the receive frequency of the selected channel, bypassing or “talking around” the repeater. This function may be used on any channel that is programmed to a frequency pair (repeater channel). CG Channel Guard Disable Press the [CG] button to disable or enable Channel Guard operation on analog channels.
Operation DMH Series VHF Radio PA Public Address Press the [PA] button to turn the Public Address system on or off. When PA is on, pressing the microphone PTT switch causes audio to be routed to the audio amplifier without enabling the transmitter. ACC Accessory Press the [ACC] button to turn the installed accessory on or off. Up to three ACC buttons may be installed for different accessories. 3.10 SCAN OPERATION 3.3.1 Receive Scan operates only while the radio is not transmitting.
Operation DMH Series VHF Radio restored. 3.10.3 TRANSMIT WITH SCAN ON When operating in Scan mode, the radio transmits on the channel selected by the Channel Selector knob. 1. Select a transmit channel by turning the Channel Selector knob. 2. Press and hold the PTT switch and talk in a normal voice. When the PTT switch is released, the radio continues to monitor the selected channel for the preset scan delay time before it resumes scanning. 3.10.
Operation DMH Series VHF Radio 3.11 PRIORITY SCAN Priority Scan enables the radio to receive on any channel while monitoring for a message on the designated priority channel(s). The radio samples each priority channel at a preset rate (.25-2.0 seconds) regardless of activity on any other channel. Priority Scan operates only while the radio is not transmitting and can be used in combination with scan operation.
Operation DMH Series VHF Radio below shows how the priority channels and the transmit channels are selected in each mode. 3.11.3 Mode A Mode B Mode C Priority Channel Channel Knob Preset Preset Transmit Channel Channel Knob Channel Knob Priority Channel PRIORITY MODE A WITH SCAN In Priority Mode A, the priority channel is set by the Channel Selector knob. Priority Mode A is seldom used by itself because the radio receives and transmits only on the knob-selected channel.
Operation DMH Series VHF Radio to the priority channel and holds for the duration of the transmission. To reply to a message heard on the priority channel, press the PTT switch. The radio transmits only on the priority channel when Priority Scan is on. Once activity has ceased on the priority channel, the radio returns to the receive channel on the Channel Selector knob. 3.11.5.1 PRIORITY MODE C WITH SCAN With Priority Scan and Channel Scan on, the radio scans until it locks on to an active channel.
Operation DMH Series VHF Radio or priority channel if Talkback Scan is enabled, or the Priority 1 channel if TX on PR1 is enabled. To alert the user that the radio is in Unit-To-Unit Mode, a beep will periodically sound until the unit is returned to normal Operating Mode. If the RTX channel’s Digital Squelch Mode is set to ‘selective’, the radio will accept group calls, correctly addressed Unit-To-Unit calls, and if RX Mode is set to mixed, analog signals.
Operation DMH Series VHF Radio radio will beep twice. The display will show the ID of the calling unit. If the ID matches one of the Call List IDs, the associated label will be displayed along with the RX and phone icons. Otherwise the numeric ID will be displayed along with the RX, phone, and ID icons. The calling unit’s ID will be displayed for the duration of the reception, and once the signal goes away, for a programmed hold time.
Operation DMH Series VHF Radio b. Press the [FCN] key to shift the display left by one position, leaving position 8 blank. c. Press the [PRI] key repeatedly to enter the next character, or press the [FCN] key a second time to enter a blank space. d. To abandon changes, press the [CLR] key, restoring the original label. e. Press the [ENT] key to store changes. 3.12.7 PROGRAMMING A NUMERIC ID Press [ENT] to display the numeric ID. Press [CLR] enter the new ID (up to 7 digits).
Operation DMH Series VHF Radio 3.14 USER SELECTED CHANNEL GUARD User Selected Channel Guard is only available on radios equipped with a keypad microphone. Not all microphones support this function. Contact your dealer to determine which features are available with your microphone and have been enabled in the radio. When the radio is being programmed with transmit and receive frequencies for each channel, a receive Channel Guard value and a transmit Channel Guard value can also be assigned to each channel.
Operation DMH Series VHF Radio This timer is also used to allow for Talkback Scan, Mixed Mode Talkback, and UnitTo-Unit Callback. 3.15.2 HI/LO POWER Each channel in the radio can be individually programmed to always transmit in lowpower mode, regardless of the position of the radio's LPW button (or microphone keypad [FCN] menu setting). If the programming for the channel allows high-power transmissions, the power level can be selected with the LPW button or the keypad [FCN] menu. 3.15.
Operation 3.15.6.1 DMH Series VHF Radio BUSY CHANNEL INDICATION The yellow Busy Channel Indicator glows if there is carrier activity on the selected channel. If the selected channel is a Channel Guard channel and the proper Channel Guard value is not detected, the Busy Channel Indicator remains on for the duration of the carrier activity and no message is heard. During Scan and Priority Scan operation, the Busy Channel Indicator glows when activity is detected on any channel on the Scan List.
Operation DMH Series VHF Radio 3.16 ALPHANUMERIC DISPLAY FEATURES The Alphanumeric Display can be programmed to operate in Numeric Mode, displaying channel numbers instead of labels. Display annunciators indicate the following information: ALPHANUMERIC INDICATION PR -Priority Channel PRG -Programming Mode (includes PR) TX -Transmit RX -Receive SCN -Scan List Channel -Flashing SCN indicates scanning in progress, and RX SCN indicates receiving on a scanned channel.
Operation DMH Series VHF Radio DMH Series mobile radios can be programmed with the following features: 3.16.2 CHANNEL LABELS You can program the radio with a label for each of the 25 channel groups and a label for each of the 16 channels within each group. To display the channel number associated with a channel label: 1. Press the microphone’s [#] key to display the group number. 2. Press the [#] key again to display the channel number. 3. Press and hold the [#] key to display the channel label. 4.
Operation DMH Series VHF Radio 3.17 DEFINITIONS AND ACRONYMS Page 3-24 ANI Automatic Numeric Identification CG Channel Guard CLR Clear Cloning The process of copying data from one radio, called “master,” to other radios, called “slaves” or “clones.” Channel Guard A subaudible tone, a code (analog) or a Network Access Code (digital) for selective calling and receiving. Detent The click/hesitation you feel as you turn a knob from one position to another.
