Radioddity DB25-D Service manual

© Radioddity page 1 of 175
V1.0, February 2022
DB25-D
extended manual

Radioddity Extended manual for Radioddity DB25-D v1.0
© Radioddity page 2 of 175
Overview of Radioddity.......................................................................................................... 11
1Disclaimer ....................................................................................................................... 12
2Product safety and RF exposure for portable radios................................................... 13
2.1 Notes on the use of the radio ................................................................................... 13
2.2 Maintenance and Cleaning........................................................................................ 14
Maintenance ........................................................................................................................ 14
Cleaning................................................................................................................................ 14
3What is in the box? ......................................................................................................... 15
4Preparation for operating the radio.............................................................................. 16
4.1 Radio installation ........................................................................................................ 16
4.2 Power supply options................................................................................................. 17
Mobile Operation ................................................................................................................ 17
Base Station Operation ...................................................................................................... 18
Replace fuse......................................................................................................................... 19
4.3 Antenna connection ................................................................................................... 20
4.4 Accessories connection.............................................................................................. 21
External speaker/headset and microphone.................................................................... 21
Speaker-Microphone .......................................................................................................... 21
4.5 Keypad operations...................................................................................................... 22
4.6 Radio controls ............................................................................................................. 22
Parts description & function applications........................................................................ 23
Status Icons.......................................................................................................................... 27
Transmit / Receiving Icons ................................................................................................. 29
LED Indicators...................................................................................................................... 29
Programmable Function keys............................................................................................ 30
Keys and ENC (channel Selector) operation .................................................................... 30
4.7 Main functions description........................................................................................ 31
Common functions ............................................................................................................. 31
Digital Functions ............................................................................................................ 32
Analog Functions ........................................................................................................... 32
4.8 Operations for Speaker-Microphone keypad ......................................................... 33
Keystrokes............................................................................................................................ 33
5Basic Operation .............................................................................................................. 34
5.1 Turning the radio On/Off ........................................................................................... 34
5.2 Adjust Volume ............................................................................................................. 34
5.3 Adjust Squelch............................................................................................................. 34
5.4 Switch Bands ............................................................................................................... 34
5.5 Busy Channel Lockout ........................................................................................... 35

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5.6 Wide/ Narrow Band ............................................................................................... 35
5.7 CTCSS / DCS ............................................................................................................ 35
5.8 Channel Selection ....................................................................................................... 35
5.9 Switch between VFO and Channel Mode ................................................................ 36
5.10 VFO Frequency Set...................................................................................................... 36
5.11 Zone / Channel Selection ........................................................................................... 36
5.12 Monitor ................................................................................................................... 36
5.13 Permanent Monitor ............................................................................................... 36
5.14 Repeater / Talk Around ........................................................................................ 37
5.15 Emergency Alarm .................................................................................................. 37
5.16 Scan On/Off ................................................................................................................. 37
5.17 Roaming On / Off ........................................................................................................ 38
5.18 1750Hz Pilot tone ................................................................................................... 38
5.19 Promiscuous Mode ............................................................................................... 38
6Using the radio menu .................................................................................................... 39
6.1 Accessing the menus and operations ...................................................................... 40
7Placing a PTT Call............................................................................................................ 41
7.1 High / Low power........................................................................................................ 41
7.2 Select the transmitting band..................................................................................... 41
7.3 Receive and Answer to a digital radio call .......................................................... 41
7.4 Receive and Answer to an analog radio call ...................................................... 43
8Special DMR functions .............................................................................................. 44
Remote monitor ............................................................................................................. 44
Remote Kill ...................................................................................................................... 44
Radio Detection .............................................................................................................. 44
Radio Revive ................................................................................................................... 45
Call Alert .......................................................................................................................... 45
GPS .................................................................................................................................. 45
Record ............................................................................................................................. 45
DTMF ............................................................................................................................... 45
Encryption ....................................................................................................................... 45
9The radio Menu functions in detail ............................................................................... 46
9.1 Contacts .................................................................................................................. 46
Contact list ...................................................................................................................... 46
New Contact ................................................................................................................... 47
Manual Dial ..................................................................................................................... 48
Ham Contacts ................................................................................................................. 48

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Ham Group Contacts ..................................................................................................... 50
9.2 Message ............................................................................................................ 51
Network support for short messages .............................................................................. 51
CreateMsg ....................................................................................................................... 52
Common Messages CommMsg ................................................................................... 53
lnbox ................................................................................................................................ 54
Outbox ............................................................................................................................ 55
Draftbox .......................................................................................................................... 56
9.3 Call Log .............................................................................................................. 57
Dialed Calls (DialedNumbs) .......................................................................................... 57
Received Calls ................................................................................................................. 58
Missed Calls .................................................................................................................... 59
9.4 Scan ......................................................................................................................... 60
Scan....................................................................................................................................... 60
Scan List................................................................................................................................ 60
Scan Mode............................................................................................................................ 61
Roam Setting........................................................................................................................ 61
Precautions for roaming .................................................................................................... 64
9.5 Zones & Channel ................................................................................................... 64
9.6 Local Set .................................................................................................................. 65
Language .............................................................................................................................. 65
Keypadlock ........................................................................................................................... 65
Backlight ............................................................................................................................... 66
LED indicator (LEDs)............................................................................................................ 66
Display Mode ....................................................................................................................... 67
VOX........................................................................................................................................ 68
Factory Reset ....................................................................................................................... 68
9.7 Parameters ............................................................................................................. 69
TOT ........................................................................................................................................ 69
Power.................................................................................................................................... 69
Slot/Repeat ..................................................................................................................... 70
Encryption (ENC Level) .................................................................................................. 71
Squelch Level (SQ level) ................................................................................................. 71
Wide / Narrow Band (Band) .......................................................................................... 71
Busy Channel Lockout (BCLO) ...................................................................................... 72
Signaling .......................................................................................................................... 72
CTCSS Phase Reverse (Ctcss Tail) ................................................................................. 73
9.8 Tone Set .................................................................................................................. 74
Profiles.................................................................................................................................. 74
Key Tone (KeyTone)............................................................................................................. 74
Message Tone (MsgTone) ............................................................................................. 74
Private Call Ring Tone (PCallTone) ............................................................................... 75
Group Call Ring Tone (G Call Tone) ............................................................................. 75
Alert Ring Tone (AlertTone) .......................................................................................... 75
Power On Tone (FM Call Tone) .................................................................................... 76

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9.9 Appendix ................................................................................................................ 76
GPS ........................................................................................................................................ 76
FM Radio............................................................................................................................... 77
Time ...................................................................................................................................... 78
DTMF ............................................................................................................................... 79
Headset+Speaker ................................................................................................................ 79
APRS ...................................................................................................................................... 80
9.10 Record ................................................................................................................ 81
9.11 Device Info .............................................................................................................. 82
9.12 Channel Edit ........................................................................................................... 83
10 Programming with the CPS........................................................................................ 85
10.1 Install device driver..................................................................................................... 85
10.2 Install CPS .................................................................................................................... 86
10.3 Start CPS....................................................................................................................... 89
Special functions ................................................................................................................. 90
Safe factory settings to a file ............................................................................................. 90
Connect to the radio ........................................................................................................... 90
Read codeplug from DB25-D............................................................................................. 91
Safe codeplug to file ........................................................................................................... 92
Write codeplug to DB25-D ................................................................................................. 92
Open existing codeplug...................................................................................................... 93
FactoryReset ........................................................................................................................ 93
11 Make changes to your settings.................................................................................. 95
11.1 Device Info ................................................................................................................... 95
Factory Number .................................................................................................................. 95
Serial Number...................................................................................................................... 95
Model Number .................................................................................................................... 96
Firmware Version ................................................................................................................ 96
Version Data......................................................................................................................... 96
Frequency Range................................................................................................................. 96
The Latest Update ............................................................................................................... 96
Firmware ID.......................................................................................................................... 96
11.2 Basic Parameters ........................................................................................................ 96
Radio Name.......................................................................................................................... 97
Rolling Code ......................................................................................................................... 97
Language .............................................................................................................................. 97
TOT ........................................................................................................................................ 97
Busy Channel Lockout ........................................................................................................ 98
VOX........................................................................................................................................ 98
VOX Sensitivity ..................................................................................................................... 98
Power-saving........................................................................................................................ 98
Power Saving Ratio ............................................................................................................. 98
Save power startup time .................................................................................................... 99

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Scanmode............................................................................................................................. 99
End-tone types..................................................................................................................... 99
Squelch (A) Level .......................................................................................................... 100
Squelch (B) Level .......................................................................................................... 100
Radio ID ......................................................................................................................... 100
Backlight ON/OFF .............................................................................................................. 101
Keylock................................................................................................................................ 101
Roaming ............................................................................................................................. 101
Roaming Mode .................................................................................................................. 102
RSSI threshold.................................................................................................................... 102
Connect Check Timer........................................................................................................ 102
Repeater Check Timer ...................................................................................................... 103
Connect Time..................................................................................................................... 103
Record Set ..................................................................................................................... 103
11.3 Common Menus ....................................................................................................... 104
11.4 Prompt Tone.............................................................................................................. 104
Profiles................................................................................................................................ 105
SMS prompt .................................................................................................................. 105
Private Call Tone .......................................................................................................... 105
Group Call Tone ........................................................................................................... 105
Roaming restart prompt .................................................................................................. 105
Repeater lock prompt....................................................................................................... 105
Keytone............................................................................................................................... 106
Keytone volume................................................................................................................. 106
Low Battery Alert tone...................................................................................................... 106
Low Battery Alert volume................................................................................................. 106
Boot ringtone..................................................................................................................... 106
Call hang up .................................................................................................................. 107
11.5 Indicator ..................................................................................................................... 107
All Indicators ...................................................................................................................... 107
TX Indicator ........................................................................................................................ 108
RX Indicator........................................................................................................................ 108
Scanning Indicator ............................................................................................................ 108
Low battery Indicator........................................................................................................ 108
11.6 Preset Buttons........................................................................................................... 109
Long Press Duration ......................................................................................................... 109
Available Function for the Preset Buttons ..................................................................... 110
11.7 Mic Gain ..................................................................................................................... 111
MIC Gain 1 ON/OFF........................................................................................................... 112
MIC Gain 1 .......................................................................................................................... 112
MIC Gain 2 ON/OFF........................................................................................................... 112
MIC Gain 2 .......................................................................................................................... 112
11.8 Quick Msg ............................................................................................................. 113
11.9 DMR Service ......................................................................................................... 113
Remote monitor duration .......................................................................................... 113

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Remote Monitor Decode ............................................................................................ 114
Remote Kill Decode ..................................................................................................... 114
Radio Detection ............................................................................................................ 114
Radio Revive ................................................................................................................. 115
Call Alert ........................................................................................................................ 115
Group Call Hang Time ................................................................................................. 115
Private Call Hang Time ................................................................................................ 115
Import Delay ................................................................................................................. 116
DTMF Duration (On-time) ........................................................................................... 116
DTMF Interval (Off-time) ............................................................................................. 116
DTMF Volume ............................................................................................................... 116
DTMF code .................................................................................................................... 117
GPS ...................................................................................................................................... 117
GPS interval........................................................................................................................ 117
GPS channel ....................................................................................................................... 117
Mandown ........................................................................................................................... 117
Mandown Interval ............................................................................................................. 118
Mandown Angle................................................................................................................. 118
Mandown Alarm Duration ............................................................................................... 118
Inactive Time...................................................................................................................... 118
Pre-alarm Time .................................................................................................................. 118
Response transmission interrupt ................................................................................... 118
Scrambling frequency....................................................................................................... 118
Keylock Password On/Off ................................................................................................ 118
Keypad Password .............................................................................................................. 119
11.10 APRS........................................................................................................................ 119
Analog APRS .................................................................................................................. 119
Digital APRS .................................................................................................................. 120
Manual TX Interval[s] ................................................................................................... 120
APRS Auto TX Intervals[s] ................................................................................................. 120
Beacon ................................................................................................................................ 121
Latitude (degrees) ............................................................................................................. 121
Longitude (degrees) .......................................................................................................... 121
TX Freq [MHz] ............................................................................................................... 122
TX QT/DQT .................................................................................................................... 122
Transmit Delay ............................................................................................................. 123
Prewave Time ............................................................................................................... 123
Transmit Power ............................................................................................................ 123
APRS Tone ..................................................................................................................... 123
Destn SSID ..................................................................................................................... 124
Destn Call Sign .............................................................................................................. 124
Your SSID............................................................................................................................ 124
Your Call Sign ................................................................................................................ 125
APRS Symbol Table ........................................................................................................... 125
APRS Map Icon................................................................................................................... 125
APRS Signal Path .......................................................................................................... 127
Your Sending Text ........................................................................................................ 127

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No........................................................................................................................................ 127
Report Channel.................................................................................................................. 127
APRS TG ......................................................................................................................... 128
Report Slot .................................................................................................................... 128
Call Type ........................................................................................................................ 128
PTT ................................................................................................................................. 128
11.11 Encryption ........................................................................................................ 129
11.12 Contacts ............................................................................................................ 129
Contact list .................................................................................................................... 129
Ham contacts ............................................................................................................... 131
Ham groups .................................................................................................................. 133
11.13 Digital Alarm List ............................................................................................. 135
11.14 Scan List ................................................................................................................. 135
Scan List.............................................................................................................................. 136
Talkback.............................................................................................................................. 137
Scan TX Mode .................................................................................................................... 137
Appointed Channel ........................................................................................................... 137
Optional Channel .............................................................................................................. 138
Selected Channels ............................................................................................................. 138
11.15 RX Group .......................................................................................................... 139
11.16 Zone [Channel]...................................................................................................... 139
Zone name ......................................................................................................................... 139
12 Setup of channels..................................................................................................... 140
12.1 Z-1 ............................................................................................................................... 140
12.2 CH mode .................................................................................................................... 140
12.3 CH Name .................................................................................................................... 140
12.4 RX Freq ....................................................................................................................... 140
12.5 TX Freq........................................................................................................................ 141
12.6 Power.......................................................................................................................... 141
12.7 Only RX ....................................................................................................................... 141
12.8 Alarm .......................................................................................................................... 141
12.9 Prompt ....................................................................................................................... 142
12.10 PCT (Private Call Type) .................................................................................... 142
12.11 RX TS ................................................................................................................. 142
12.12 TX TS .................................................................................................................. 143
DMR use with simplex hotspot .................................................................................. 143
12.13 RX CC (Color Code) .......................................................................................... 144
12.14 TX CC ................................................................................................................. 144

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12.15 Msg Type .......................................................................................................... 144
12.16 TX Policy ................................................................................................................. 145
12.17 RX Group .......................................................................................................... 145
12.18 Encryption List ................................................................................................. 145
12.19 Scan List ................................................................................................................. 146
12.20 Contacts ............................................................................................................ 146
12.21 EAS (Emergency Alarm System) .......................................................................... 146
12.22 Bandwidth.............................................................................................................. 146
12.23 RX SQ ................................................................................................................. 147
12.24 RX QT/DQT (RX CTCSS/DCS) ........................................................................... 147
12.25 TX SQ ................................................................................................................. 148
12.26 TX QD/DQT (TX CTCSS/DCS) ........................................................................... 148
12.27 APRS........................................................................................................................ 148
13 Firmware update ...................................................................................................... 149
Install program for firmware update.................................................................................. 149
13.1 Perform Firmware update ....................................................................................... 149
14 Firmware Release notes........................................................................................... 153
15 CPS Release notes .................................................................................................... 154
16 Quickstart for common use cases........................................................................... 155
16.1 Simplex analog FM operation with other station ................................................. 155
16.2 Duplex analog FM operation with a local analog FM-repeater .......................... 156
16.3 Analog FM operation including analog APRS ........................................................ 157
16.4 Simplex digital DMR operation with other station ............................................... 158
16.5 Simplex digital DMR operation with Single-HAT hotspot .................................... 159
16.6 Duplex digital DMR operation with Dual-HAT hotspot........................................ 160
16.7 Digital DMR operation with digital repeater ......................................................... 161
17 Common problems and how to solve them........................................................... 164
18 CTCSS and DCS sub audio signaling........................................................................ 166
18.1 Supported CTCSS frequencies ................................................................................ 166
18.2 Supported DCS (Digital Coded Squelch) ................................................................ 166
18.3 Supported DCS-I (Digital Coded Squelch Inverted) values .................................. 167

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19 Connectivity .............................................................................................................. 168
19.1 Power connector....................................................................................................... 168
19.2 HF Antenna ................................................................................................................ 168
19.3 GPS antenna .............................................................................................................. 168
19.4 RJ45 Speaker-Microphone ....................................................................................... 169
19.5 K1 connector ............................................................................................................. 169
20 Technical specifications of the DB25-D................................................................... 170
20.1 General specifications .............................................................................................. 170
20.2 Receiver...................................................................................................................... 171
20.3 Transmitter ................................................................................................................ 171
21 Certification .............................................................................................................. 172
21.1 FCC part 90 approval................................................................................................ 172
21.2 CE certificate.............................................................................................................. 173
22 Where to find support material............................................................................... 174
23 Revision history of this document........................................................................... 175

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Overview of Radioddity
‘You, our friend and customer, are our focus’
At Radioddity, Customers are important to us. As a Customer, your time and
money are important to you. When you buy radios online, you face a dilemma:
buy from a reputable website at a high price, or try to save money by choosing a
dealer who may or may not offer quality goods, service and advice. At
Radioddity.com, you do not have to choose between low prices and a secure
shopping experience. Whether you are buying from us for the first time or a
seasoned amateur radio operator, we always hope that with our products, prices,
content and sources, you will find exactly what you need. In recent years,
Radioddity has better met the needs of wireless device buyers by creating a secure
shopping experience. We do this by offering the highest quality products at an
affordable price and providing you with first-class service. You deserve no less.
Our promise: to give you the best shopping experience
Strong partnerships enable us to offer you the latest technology and outstanding
value for money under the Radioddity brand name. Our thoughtful and
responsive customer service teams help us deliver on our promise to you and
meet your everyday needs even better.
Whether providing you with the latest and greatest DMR and analog radios,
accessories and related products, providing outstanding technical support, or by
working with the leaders of the amateur radio industry to develop helpful content
to assist you with your purchase: Your concerns are our concerns.
We want to connect you with high quality radios at low prices. If, in your opinion,
we do not honor this promise in any way, please let us know by e-mail:
[e-mail]

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1Disclaimer
This document is intended as an enhanced version of the manual that comes with
the radio. It does describe all those details, that are required to know in order to
get the most out of your Radioddity DB25-D. If you find anything that needs
correction, please let us know via [e-mail].
We advise you to take a look at the document our engineers prepared for those
new to DMR. Check the corresponding blog-entry for more details. To be found
here: https://www.radioddity.com/blogs/all/radioddity-getting-on-air-with-your-
dmr-radio
Windows™, Linux™ and OS X™ are the properties of their respective owners.
Should any trademark attribution be missing, mistaken or erroneous, please
contact us as soon as possible for rectification.
Not all functionality is available in both operating modes of the radio. For easier
identification of those functionality, we used the following icons:
Parameter names , when displayed on the screen of the Radioddity DB25-D are
written bold&italic.
Described functionality is only available for digital DMR channels
Described functionality is only available for analog channels

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2Product safety and RF exposure for portable radios
Before using the radio, please read this manual carefully.
It contains important instructions for the safe and proper
use of the radio and operating instructions for compliance
with the limits of RF energy exposure in accordance with
applicable national and international standards.
2.1 Notes on the use of the radio
Please read the following quick start guide, as failure to comply with these rules
can be dangerous or in violation of the law.
1. Observe local regulations before using this radio, as improper use may violate
the law.
2. Turn off the radio before approaching flammable or potentially explosive
atmospheres.
3. Do not charge or replace the battery in flammable or potentially explosive
atmospheres.
4. Turn the radio off before you come near any areas with explosives.
5. Do not use a radio whose antenna is damaged, as touching the damaged
antenna may result in injury.
6. Do not try to disassemble the radio; any maintenance work should be carried
out by qualified technicians.
7. To prevent electromagnetic interference issues, turn the radio off in locations
that have signs displaying similar instructions to ‘Do not use wireless devices’
or ‘Turn cell / mobile phones off’such as inside hospitals and healthcare
facilities.
8. Do not place the radio in the area of airbag deployment in vehicles so
equipped.
9. Do not store the radio in direct sunlight or hot areas.
10. When transmitting with the radio, keep the antenna at least 5cm away from
your body or face.
11. If the radio emits any smoke or burning smells, switch the radio off
immediately and disconnect it from the car’s battery and contact your dealer.
12. Do not transmit for long periods as this may damage the radio or cause it to
become hot enough to cause injury.

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2.2 Maintenance and Cleaning
To ensure the best performance and prolong working life, please acquaint
yourself with the following for maintenance and cleaning.
Maintenance
1. Please do not scratch or puncture the device with hard or sharp object.
2. Please do not place the device in an environment which can corrode
electronic circuits or under direct solar radiation.
3. Please do not carry the device by its antenna or headset.
4. Please make sure the Speaker-Microphone plug is covered when not in use.
Cleaning
1. Please clean your device regularly by using a dry clean cloth or soft brush to
wipe the dust off the surface.
2. The keypads, control knob and housing of the device may become dirty from
use. Please use nonwoven wipes to clean them. Do not use chemicals to clean
it such as detergent, alcohol, spray or petroleum products, on the device
surface or printed labels. Chemicals can damage the housing, display and
remove the printing on the labels. Before powering on the radio, please make
sure the device is dry completely.

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3What is in the box?
Thank you for choosing a Radioddity DB25-D radio. We recommend that you first
check the delivery contents listed in the following table and keep the packaging
for later storage. If something is missing or damaged, please contact your dealer
immediately.
item
picture
Radioddity DB25-D
Mobile Radio
Adapter-cable with car-
cigarette-lighter-plug
Speaker Mic
Mini GPS Antenna
Mounting Bracket
Rack mounting Screws (2)
Programming Cable
Notes: Further accessories for your radio are available at:
https://www.radioddity.com/

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4Preparation for operating the radio
4.1 Radio installation
For sake of your own and passengers safeties, please find a safe and convenient
position in order to prevent the damage caused by moving car. Check about
suitable and allowed positions with the manufacturer of your car. Choose a
mounting location within the driver's reach that allows a view of the radio and the
road ahead. The small size makes this more of a possibility than larger under dash
radios. Typical under dash installations rely on devices with direct functions and
controls. 2 step controls are harder to perform while keeping your eyes on the
road. You can consider installing the radio in front of the front passenger seat
below the panel section or the car trunk. This will prevent your knees and legs
crashing the radio in case of an emergency brake. You should install it with good
ventilation and avoiding the direct sunlight.
1. Install the mounting bracket to the car with using the self-taping screws and flat
washers (2 pcs screws each kind).
•Screws can be put upside down (under the dashboard mounting) or upwards
the mounting bracket.
•When installing the mounting bracket, please make sure the screw side edge
with slots on the bracket are backwards.
2. Next take the radio body and it between the two side wings of the mounting
bracket. Secure the radio body to the mounting bracket using the two supplied
M4 x 10mm Rack mounting screws including their fixed washers.
•Please make sure all the screws are tight to prevent the radio's firm hold
from being lost due to the vibrations in the car.

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1. With the rotatable fixed point on the left and right sides of the Mounting
Bracket, it can tilt the main body at an appropriate angle.
4.2 Power supply options
Mobile Operation
The radio comes with a cigarette-style plug. After connecting a proper antenna
this allows immediate use within a car but due to often bad electrical connections
between the cigarette lighter socket and the cigarette plug, we recommend to use
a fused, but direct wiring to the car´s battery.
The vehicle battery must have a nominal rating of 12 V. Never connect the
Radioddity DB25-D to a 24V battery. Be sure to use a 12 V vehicle battery that has
sufficient current capacity. If the current to the DB 25-D is insufficient the display
may darken during transmission or transmitting output power may drop
excessively.
Notes: If the car battery is not fully charged or when the engine is switched off
but the battery is still not fully charged, the battery may discharge and
there will not be enough power to start the car. Please avoid using the
radio in such situations.
1. Route the DC power cable supplied with the Radioddity DB25-D directly to the
vehicle's battery terminals using the shortest path from the transceiver We
suggest you do not use the cigarette lighter socket as some cigarette lighter
sockets introduce an unacceptable voltage drop that may cause the radio to
turn off or reboot when starting a transmission. The entire length of the cable

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must be dressed so it is isolated from heat, moisture and the engine secondary
(high voltage) ignition system/cables. If you use a noise filter, the metal parts of
the car shall be fitted with an insulator to prevent it from touching the car.
2. After installing the cable, in order to avoid the risk of damp, please use heat-
resistant tape to tie together with the fuse box. Do not forget to reinforce the
whole cable.
3. Confirm the correct polarity of the connections, then attach the power cable to
the battery terminals: Red connects to the positive (+) terminal and black
connects to the negative (-) terminal.
4. Reconnect any wiring removed from the negative terminal.
5. Connect the DC power cable to the transceiver's power supply connector. Press
the connectors firmly together until the locking tab clicks. Additional clip-on
ferrites applied to the power cable and close to the radio will prevent any HF
radiation to enter the power supply lines.
Notes: If you use the Radioddity DB25-D for a long period and the vehicle battery
is not fully charged or when the car engine is OFF, the car battery may
become discharged and will not have sufficient power left to start the
vehicle. Avoid using the Radioddity DB25-D in these conditions.
Base Station Operation
In order to use the Radioddity DB25-D for fixed station operation you will need a
separate 13.8 V DC power supply (not included). Please contact your local dealer
about it. The recommended current capacity of your power supply should be at
least 5 A.
Notes: Before connecting the DC power to the Radioddity DB25-D, be sure to
switch the DC power supply OFF. Do not plug the DC power supply into
an AC outlet until you make all connections.

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1. Make sure that both, the Radioddity DB25-D and DC power supply are off.
2. Connect the DC power cable to the regulated DC power supply and ensure that
the polarity is correct. (Red: positive; Black: Negative}. Use the supplied DC
power cable to connect the Radioddity DB25-D to a regulated power supply. Do
not substitute a cable with smaller gauge wires.
3. Connect the radio's DC power connector to the connector on the DC power
cable. Press the connectors firmly together until the locking tab clicks.
Additional clip-on ferrites applied to the power cable and close to the radio will
prevent any HF radiation to enter the power supply lines.
4. Connect a properly matched dual-band antenna to the radios antenna port.
Replace fuse
If the fuse is blown, please find out the cause and then solve the problem. After
the problem is fixed then replace the fuse. But if after re-installation the fuse is
still blown, please disconnect the power cord and contact the local authorized
dealer or authorized service center for assistance.
Fuse position
Fuse rated current
Radio (in DC cable)
5 A
DC power cord
10 A
Notes: Please use only the specified type and the rated value of the fuse;
otherwise it might damage the radio.

Radioddity Extended manual for Radioddity DB25-D v1.0
© Radioddity page 20 of 175
4.3 Antenna connection
Before operation, you must first install a properly matched antenna for the
optimal transmit coverage. The radio will have best performance if the
appropriate antenna is properly installed. A low loss coaxial feeder line with 50 Ω
impedance is used to match the input impedance of the radio. If the transmission
impedance of the feeder line is less than 50 Ω the antenna connection will reduce
the effectiveness of the antenna system, and will cause interference to the nearby
radio and television receivers, radio receivers and other electronic devices, and
even damage the radio.
Notes: If transmitting without an antenna or other matched load line, it could
damage the Radioddity DB25-D. The antenna must be connected to the
radio before transmitting. All base stations should be equipped with
lightning arrester to reduce the risk of fire, electric shock or radio damage.