Uniden UM255 User manual

UM255
27MHz Radio
AM-Marine / AM-CB
For more exciting new products please visit our website:
Australia: www.uniden.com.au

2
Table of Contents
Table of Contents .................................................................................................2 (this page)
Introduction................................................................................................................................3
Features..................................................................................................................................3
Manual overview.....................................................................................................................3
Conventions.........................................................................................................................3
Getting Started...........................................................................................................................4
What's Included...................................................................................................................................4
Parts of the Radio ...............................................................................................................................5
Using Your Radio.......................................................................................................................8
Turning on the Radio ..............................................................................................................8
Setting the Band Mode (AM Marine / AM CB)........................................................................8
Setting the Volume..................................................................................................................8
Setting the Squelch Level (Manual Squelch)..........................................................................8
Enabling the Auto Squelch (ASQ)...........................................................................................9
Chaniging the Channel...........................................................................................................9
Making a Transmission...........................................................................................................9
Instant (Priority) Channel......................................................................................................10
Channel 88|9 ........................................................................................................................10
Dual Watch ...........................................................................................................................10
ANL (Automatic Noise Limiter) .............................................................................................10
Scanning (Open Scan /Group Scan) ...................................................................................11
SCAN | MEM ........................................................................................................................11
MENU...................................................................................................................................12
MENU: DISPLAY BRIGHTNESS..........................................................................................12
MENU: OS/GS SCAN...........................................................................................................12
MENU: RF GAIN...................................................................................................................12
MENU: PA MODE.................................................................................................................13
MENU: CALL TONE .............................................................................................................13
MENU: ROGER BEEP .........................................................................................................13
MENU: KEY TONE...............................................................................................................14
MENU: SP MODE.................................................................................................................14
MENU: CONTRAST .............................................................................................................14
SIREN...................................................................................................................................14
Installing the Hardware...........................................................................................................15
Mounting the Radio...............................................................................................................15
Installing an Optional Flush Mount Bracket..........................................................................16
Connecting the Radio...........................................................................................................16
Connecting Accessories .......................................................................................................18
Connecting to an external speaker.......................................................................................18
Connecting to an external PAspeaker..................................................................................18
Maintenance and Troubleshooting........................................................................................24
Specifications..........................................................................................................................20
Channel and Frequencies......................................................................................................................22
Regulations and Safety Warnings.....................................................................................................23
Antenna Selection and Installation .......................................................................................23
Two Year Limited Warranty.....................................................................................................24
Mounting Bracket Template....................................................................................................25
Table of Contents

3
Introduction
Features
• Built for Rugged Australian Marine Conditions
• 2 Year Warranty
• Dual Speakers: One speaker is mounted at the front of the unit allowing better sound clarity
and the second speaker is built into the microphone hand piece.
• 4 Watts Maximum TX Output Power
• 27MHz Dual Band: The UM255 can operate in the 27MHz AM Marine band for Inshore
Boating Radio Services, or the 27MHz AM CB band
• 10 AM Marine Channels | 40 AM CB Channels: Allows you to choose from all the
Australian Inshore Boating Radio Services channels, or Australian AM CB channels to
transmit or receive messages.
• Splashproof: Meets the world standard JIS4 level. Being defined as no harmful influence by
receiving a splash of water from any direction.
• Rugged Speaker Microphone: With Channel Select, One Touch Ch88|9 and Dual Watch
keys.
• Variable Squelch Level Knob: Manually adjust the threshold of the receiver to eliminate
background noise whenever a transmission is not being received
• Automatic Squelch (ASQ): Set to ASQ to enable the Automatic Squelch.
• Volume Control Knob: Rotary Power on/off and Volume Control
• Backlit Keypad and LCD Display: The keypad and Extra Large Liquid Crystal Display (LCD)
is backlit for easy viewing at night or in low light situations, and features a dimmer function
• Built-in PA Output: Connect optional PA speaker for Public Address and Siren Function.
• Siren Alert Function: Alert nearby vessels with connection of an optional PA speaker
• RF Gain Function: Adjust to boost the strength on incoming signals.
• ANL (Automatic Noise Limiter) Function: Reduces unwanted signal noise for better
clarity.
• One Touch Channel 88|9 Recalling: Instantly switch to the emergency Ch 88 (Marine
band) or CH9 (CB band) with the touch of one button on the radio or the microphone.
• Open Scan: Scans all the channels in memory and locks on active channels.
• Group Scan (GS) with Priority Channel Watch: Allows the user to select the channel they
want to monitor / listen to in a group, along with a priority channel (priority watch).
• Dual Watch Function: Allows you to monitor Ch 88 (Marine band) or CH9 (CB band) for
activity intermittently while monitoring another channel at the same time.
• Roger Beep: Confirmation tone indicates the completion of your transmission.
• Call Tone Function: Choose from one of 5 ringing tones to initiate your transmission with
the touch of one button.
Manual overview
Conventions
This manual uses several different type styles to help you distinguish between
different parts of the radio:
• BOLD CAPITALS indicates an actual button or knob on the radio or microphone.
• Upper and Lower case bold indicates a connector or label on the radio.
• Italics indicate text on the display, such as menu options, prompts, and conrmation mes-
sages.
Introduction

Getting Started
4
What's Included
UM255 Radio
DC Power Cable
Mounting Bracket and
knobs
Microphone Hanger and
Mounting Hardware
Getting Started
CHANNEL

5
Getting Started
Table 1 - Front panel button functions
Button Press to... Press and hold to...
CHANNEL UP
Move up one channel at a
time. Move quickly up the channels.
CHANNEL DOWN
Move down one channel at a
time. Move quickly down the channels.
MENU
Go to MENU Mode Key lock
INST
Instant (Priority) Channel
recall Save channel as the Instant (Priority) Channel
88|9 | DUAL
Toggle channel between the
current channel and CH88 (in
Marine band) or CH9 (in CB
band).
Select Dual Watch Function
SCAN | MEM
Select Scan function Memory or remove scan channel
SIREN
Siren tone one cycle output Siren tone output continually
ANL | CALL
ANL (Automatic Noise Limiter)
on/off Initiate Call tone transmission
CHANNEL
ANL-CALL
SCAN-MEM
INST
88|9-DUAL
MENU
SIREN SQUELCH-ASQ
knob (turn clockwise
to decrease channel
noise)
LCD Display CHANNEL UP &
CHANNEL DOWN
button
VOLUME-PWR
(power) knob
(turn clockwise to
increase volume)
Parts of the Radio

Getting Started
6
Table 2 - Rear panel connector functions
Connector Connects to For details, see
Antenna connector External AM antenna with
a male PL259 (SO238)
connector and 50 Ω
impedance.
Minimum 1.2m, 3dB rated
antenna for sailboats, 2.4m, 6
dB rated for power boats.
Connecting the radio,
page 16.
Power connector Nominal 13.8 VDC power
supply with negative ground
(10.8 VDC to 15.6 VDC)
(Red wire +, black wire -).
Connecting the radio,
page 16.
PA connector External PA (Public Address)
speaker (optional). Connecting accessories, page 18.
Speaker connector External speaker (optional). Connecting accessories,
page 18.
Antenna Connector
(SO238)
Heat sink
PA Connector
Power Connector
Speaker Connector
Parts of the Radio

7
Getting Started
Table 3 - Microphone button functions
Button Press to... Press and hold to...
PTT
(PUSH TO TALK) Cancel scanning and stay on a
channel. Talk on a channel.
88 | 9 -
DUAL WATCH Toggle channel between the current
channel and CH88 (in Marine band
mode) or CH9 (in CB band mode).
Select Dual Watch
Function
CHANNEL UP Move up one channel at a time Move quickly up the
channels.
CHANNEL DOWN Move down one channel at a time Move quickly down the
channels.
PTT
(PUSH-TO-TALK)
Button
88 | 9 - DUAL WATCH
Button
CHANNEL UP & DOWN
Buttons
Parts of the Radio

Using Your Radio
8
Using Your Radio
Turning on the Radio
Turn the VOLUME-PWR knob clockwise to turn on the radio.
When it powers on, the radio selects the last channel used.
Setting the Band Mode (AM Marine / AM CB)
The UM255 can operate in the Australian 27MHz AM Marine band for Inshore
Boating Radio Services, or the Australian 27MHz AM CB band.
To switch between band modes:
Press and hold INST and 88|9-DUAL buttons of the main unit while turning power on.
Turn the VOLUME-PWR knob clockwise to increase the speaker volume; turn it
counter-clockwise to decrease the volume.
Setting the Volume
Setting the Squelch Level (Manual Squelch)
The squelch feature reduces the level of static on the speaker by filtering out the
background channel noise. At the lowest squelch level, the speaker plays all radio
signals, including any noise on the channel. Setting the squelch level higher filters out
channel noise and lets only actual radio transmissions through.
Weak signals
No
Squelch Medium
Squelch High Squelch
Strong signals
Noise

9
Using Your Radio
While listening to a channel, adjust the SQUELCH-ASQ knob until the noise is
filtered out and you can only hear the transmission. The SQ icon appears on the
display whenever squelch is in manual mode (not ASQ mode).
If you switch to a channel with a lot of noise or with a weak transmission, you may
need to adjust the squelch level again.
NOTE 1: Setting the squelch level too high may prevent you from hearing weaker
transmissions. If you are having difficulty hearing a transmission, try setting the
squelch level lower.
NOTE 2: For additional filtering effects, adjust the manual squelch in conjunction with
the RF GAIN setting, see page 12.
Changing the Channel
Press the CHANNEL UP or CHANNEL DOWN button briefly to scroll through the
channels one channel at a time. Press and hold the CHANNEL UP or CHANNEL
DOWN button to quickly scroll through the channels.
Enabling the Auto Squelch (ASQ)
Use the Auto Squelch and the raido will be optimised to hear medium to stong (nearby)
signals.
Turn the SQUELCH-ASQ knob to the ASQ position to enable Auto Squelch mode.
The AQ icon appears on the display when ASQ is enabled.
Making a Transmission
In AM Marine Band mode the UM255 AM radio uses the Inshore Boating Radio
Service Band channels.
In AM CB Band mode the UM255 AM radio uses the AM-CB Band channels (see
Channels and Frequencies, page 22).
Select the desired channel. Listen to make sure there is no activity on the channel.
Press PTT on the microphone handset and speak normally into the microphone. Hold
it approximately 7cm from your mouth. The TX icon appears on the display whenever
the radio is transmitting
Release PTT to end the transmission and listen for a reply.

Using Your Radio
10
Instant (Priority) Channel
Programmable one-touch Instant channel button.
Press INST button to go to the Instant (Priority) Channel.
To set the Instant (Priority) channel:
First press CHANNEL UP or CHANNEL DOWN to select a desired channel and then
press and hold the INST button to store the channel as the Instant (Priority) channel.
Channel 88 | 9
Instantly switch to emergency Channel 88 (AM Marine Band mode) or Channel 9 (CB
Band mode).
Press 88|9-DUAL on the handset or base.
Dual Watch
Dual Watch will monitor the Instant (Priority) Channel and the current channel for
activity. Dual Watch is suspended when there is activity and resumes after activity
ceases.
Press and hold 88|9-DUAL on the handset or base. The DW icon appears and a
short tone beep is heard.
To cancel Dual Watch press and hold 88|9-DUAL on the handset or base. DW icon
disappears.
ANL (Automatic Noise Limiter)
ANL will reduce harsh background noise caused by some transmission interference.
Press ANL-CALL to turn ANL ON or OFF.
If ANL is ON the ANL icon will remain on the display.

11
Using Your Radio
Scanning
The UM255 has a scanning feature that allows you to search for active channels
automatically. Furthermore, the UM255 is designed to have two types of scanning;
Open Scanning (OS) and Group Scanning (GS), to give you flexibility and allow you
to use the radio more effectively.
Open Scan Mode (OS)
Allows continuous scanning of all selected channels.
If an active channel is found, scanning will stop on that channel. If the received
signal ceases, the unit will wait 3 seconds for the signal to return, otherwise
scanning resumes.
The scan direction can be changed at any time by pressing a channel key.
After transmission in scan mode, the radio will wait 20 seconds for the signal to
return, otherwise scanning resumes.
To skip the active channel, press any of the channel keys on the base or handset.
Group Scan Mode (GS)
Includes the accessory feature Priority Watch which allows you to monitor the
Instant (Priority) Channel while scanning.
If the Instant (Priority) Channel becomes active the radio will stay on that channel
for as long as the signal is present. If the received signal ceases, GS Scanning
continues after 3 seconds.
If scanning stops on a channel which is not the Instant (Priority) Channel, the
UM255 will continue monitoring the Instant (Priority) Channel for activity while
listening to the active one.
Select which Scanning Mode you wish to use, OS or GS (see MENU, page 12)
Press SCAN-MEM and Scanning starts and ‘SC’ flashes on the display.
Press SCAN-MEM again to exit the scanning mode and return to the initial channel.
MEM: Store/Remove Channels from SCAN Memory
Select which Scanning Mode you wish to use, OS or GS (see Menu, page 12)
Select the channel you want to store.
Press and hold SCAN-MEM to add channel to SCAN memory. Micon appears and a
short tone beep is heard.
To remove the channel from SCAN memory, press and hold SCAN-MEM. The Micon
disappears.
SCAN

Using Your Radio
12
MENU
Menu Order List
1. Display Brightness BRIGHT
2. OS/GS SCAN SCAN
3. RF Gain RF GAIN
4. PA Mode PA MODE
5. Call Tone CALL TONE
6. Roger Beep ROGER BEEP
7. Key Tone KEY TONE
8. SP Mode SP MODE
9. Contrast CONTRAST
MENU: Display Brightness
MENU: OS/GS SCAN
MENU: RF GAIN
The RF Gain function increases the radio's sensitivity to signals. Set to a high level
to better tune to weak signals, or set to a low level if signals are close and strong
(distorted). Can be used in combination with the manual squelch.
Press MENU three times, the RF Gain setting flashes on the display.
Press CHANNEL UP or CHANNEL DOWN button to select a desired RF Gain level
(total 9 levels).
The Ricon displays whenever the RF Gain is enabled (not set to OFF).
Press and hold MENU to save the setting and exit menu mode.
Press MENU two times, the OS/GS Scan setting flashes on the display.
Press CHANNEL UP or CHANNEL DOWN button to select OS or GS.
Press and hold MENU to save the setting and exit menu mode.
Press MENU one time, the Screen Brightness setting flashes on the display.
Press CHANNEL UP or CHANNEL DOWN button to select a desired brightness
level (total 5 levels).
Press and hold MENU to save the setting and exit menu mode.

13
Using Your Radio
MENU: CALL TONE
MENU: PA MODE
Call Tone transmits a wake up (calling) tone when initiated, (see Front panel button
functions, page 5.)
To select a Call Tone pattern:
Press MENU five times, the Call Tone setting flashes on the display.
Press CHANNEL UP or CHANNEL DOWN button to select desired call tone (5
tones). The tone sounds through the speaker when changing selection.
Press and hold MENU to save the setting and exit menu mode.
An optional external PA Speaker is required to use this feature.
PA mode redirects the PTT audio to an optional external PA speaker for public
broadcast.
Press MENU four times, the PA setting flashes on the display.
Press CHANNEL UP or CHANNEL DOWN button to select PA ON or OFF.
Press and hold MENU to save the setting and exit menu mode.
If PA setting is ON the display shows PA. Pressing 88|9-DUAL also cancels PA
mode and changes to the channel to CH88 or CH9.
To use the PA Feature:
Press and hold the microphone PTT button. Speak clearly in your normal voice
(you don’t have to shout). Use VOLUME-PWR knob to adjust the volume of the PA
speaker. Release the PTT button when you're finished talking.
MENU: ROGER BEEP
Roger Beep adds a short beep tone pattern to the end of your transmission.
Press MENU six times, the Roger Beep setting flashes on the display.
Press CHANNEL UP or CHANNEL DOWN button to select Roger Beep ON or OFF.
The RB icon displays whenever Roger Beep is on.
Press and hold MENU to save the setting and exit menu mode.

Using Your Radio
14
For best results an optional external PA Speaker should be connected to use this
feature.
The Siren feature generates a siren output via the Front speaker, Microphone
speaker and optional PA speaker for situations where you wish to alert nearby
vessels.
1. Single Cycle Siren: Lift the siren cover and press SIREN. The SIREN icon appears
and the UM255 emits a siren tone via the Front speaker, Microphone speaker and
optional PA speaker. After one cycle output, the SIREN icon disappears and the
UM255 stays in the PA mode.
2. Continuous Siren: Lift the siren cover and press and hold the SIREN button until
the end of the 3 second display count down. The SIREN icon flashes and the UM255
emits a siren tone continuously.
3. To cancel the single cycle or continuous siren; Press SIREN or PTT key. The
UM255 stays in the PA mode. Pressing 88|9-DUAL also cancels the siren and
changes to CH88 or CH9. The siren volume via PA speaker cannot be controlled.
The siren volume via Front speaker Microphone speaker can be controlled.
SIREN
MENU: CONTRAST
Press MENU nine times, the Contrast setting flashes on the display.
Press the CHANNEL UP or CHANNEL DOWN button to select desired contrast level
(total 9 levels).
Press and hold MENU to save the setting and exit menu mode.
MENU: SP MODE (MIC Speaker)
MENU: KEY TONE
Press MENU eight times, the SP Mode setting flashes on the display.
Press the CHANNEL UP or CHANNEL DOWN button to select microphone Speaker
ON or OFF.
Press and hold MENU to save the setting and exit menu mode.
Press MENU seven times, the Key Tone setting flashes on the display.
Press the CHANNEL UP or CHANNEL DOWN button to select Key Tone ON or OFF.
Press and hold MENU to save the setting and exit menu mode.

15
Installing the Hardware
Mounting the radio
The UM255 can sit angled in the mounting bracket so it can easily accommodate
the best location. First, determine the best place to mount the radio. For optimum
performance, find a location that can:
• Properly support the weight of the radio, approximately 1.1 kilograms. You may
need to use some type of anchor with the mounting screws to hold the radio,
depending on the surface.
• Keep the battery leads as short as possible.
• Keep the antenna lead-in wire as short as possible.
• Allow free air flow around the heat sink on the rear of the radio.
• Avoid interference with the ship’s compass.
Installing the Hardware
1. Install the radio into the mounting bracket, and connect the power cable and
accessory cable.
2. Position the radio into the desired location. Mark the edges of the bracket on the
mounting surface.
3. Remove the mounting bracket drill template from the back of the manual, and use
the template to mark the drill holes on the mounting surface.
4. Drill the holes for the mounting bracket; be sure to follow any special
requirements of the mounting surface.
5. Remove the bracket from the radio, and use the mounting hardware to secure the
bracket to the mounting surface.
6. Install the radio back into the mounting bracket.
Hex bolt
Washer
Spring washer
Hex nut
Mounting
bracket
Mounting
surface

Installing the Hardware
16
A optional FLUSH MOUNT BRACKET is
available for mounting the transceiver to a flat
surface such as an instrument panel.
Connecting the Radio
To operate correctly, your UM255 requires two electrical connections:
• providing it with power from the boat’s electrical system
• connecting a 27MHz AM marine antenna to the antenna connector
Power supply requirements 27MHz antenna requirements
Nominal 13.8 VDC power supply with
a negative ground (10.8 VDC to 15.6
VDC).
Power leads should be kept as short
as possible. A direct connection to the
power supply is ideal.
Minimum of #14 AWG copper wire for
extensions up to 6m, 12 AWG wire for
extensions from 6m to 10m, or 10 AWG
wire for extensions from 10 to 18m
Male PL-259 connector
50 Ω impedance
Minimum 1.2m, 3 dB rated antenna for
sailboats or 2.4m, 6dB rated antenna for
powerboats
Minimum RG-58 lead-in wire for antenna
leads up to 6m to 10m, RG-8X for an-
tenna leads from 6m to 10m, or RG-8U
for antenna leads from 10m to 18m.
13.8V DC
Power
cable
Power
connector
Black wire
(-)
Red wire
(+)
Installing to an Optional Flush Mount Bracket

17
Installing the Hardware
1. Connect the BLACK wire of the included power cable to the NEGATIVE (-) side
of your power source.
2. Connect the RED wire of the included power cable to the POSITIVE (+) side of
your power source.
3. Connect the power cable to the power connector on the back of the UM255.
(The power connector only fits one way.)
4. NOTE: To extend the life of the radio, use waterproof tape to seal electrical
connections.
5. Install your antenna according to the manufacturer’s instructions.
6. See Antenna Selection and Installation on page 23 for more details.
7. Connect the PL-259 connector from the antenna lead-in wire to the SO238
connector labeled ANTENNA on the back of the UM255.
Radio connector,
SO238 (female
PL-259) Antenna lead-in
connector,
male PL-259

Installing the Hardware
18
Connecting to an external speaker
You can use an external speaker to monitor the radio from a different part of your
boat or in a noisy environment. If you adjust the VOLUME-PWR knob on the radio, it
will also adjust the external speaker volume.
The UM255 supports an external speaker with the following specifications:
• Minimum impedance of 4 Ohms
• Minimum power handling of 10 Watts
Connecting Accessories
Connecting to an external PA speaker
You can use an external PA speaker to monitor the radio from a different part of your
boat or in a noisy environment. The UM255 supports an external PA speaker with the
following specifications:
• Minimum impedance of 4 Ohms
• Minimum power handling of 10 Watts
1. The External PA Speaker connection is a standard 3.5mm audio pin connection.
NOTE: To extend the life of the radio, use waterproof tape to seal electrical
connections.
1. The External Speaker connection is a standard 3.5mm audio pin connection.
NOTE: To extend the life of the radio, use waterproof tape to seal electrical
connections.

19
Maintenance and Troubleshooting
Maintenance and Troubleshooting
Due to its rugged design, the UM255 requires very little maintenance. However, it is
a precision electronic instrument, so you should follow a few precautions:
• If the antenna has been damaged, you should not transmit except in the case of an
emergency. A defective antenna may cause damage to your radio.
• You should arrange for periodic performance checks with your Uniden dealer.
Common questions
Problem Things to Try
The radio won’t power on. Check the power connections.
Check the fuse.
Check the master battery switch and branch
circuit that connect to the radio.
The radio won’t transmit. Make sure you are not in scan mode.
Make sure you are not trying to transmit on a
receive-only channel (see the channels and
frequency tables starting on page 22).
Make sure the duration of each transmission is
less than 3 minutes.
Noise comes out of the
speaker all the time Adjust the squelch level; it is probably too low.
I can’t hear anything (no vol-
ume) from the speaker. Adjust the squelch level; it is probably too high.
I can transmit, but no one can
hear me. Check your band setting (see Setting the Band (AM Marine mode / AM CB mode) on page ).
I can’t read the display. Adjust the contrast level (see page 14)
The display is too bright at
night. Adjust the display brightness level. (see page 12)
Where can I nd my radio’s
serial number? Look on the rear side of the radio
Engine Noise Suppression
Interference from the noise generated by the electrical systems of engines is
sometimes a problem with radios. The UM255 has been designed to be essentially
impervious to ignition noise and alternator noise. However, in some installations it
may be necessary to take measures to further reduce the effect of noise interference.
The UM255 radio DC battery wires, antenna lead, and accessory cables should
be routed away from the engine and engine compartment, and from power cabling
carrying high currents. In severe cases of noise interference, it may be necessary to
install a noise suppression kit. Contact the dealer where you purchased the radio for
more information.

Specifications
20
Table 4 - Radio specifications
(All specications are subject to change without notice.)
Specifications
General
Controls Volume-Pwr, Squelch-ASQ
Status Indicators Transmit, Receive, Scan mode, Dual Watch mode,
RF Gain on, Roger Beep on, Memory channel,
Squelch, Auto Squelch, PA and Channel Display
Display LCD (Dot Matrix)
Buttons MENU-Keylock, Channel UP, Channel DOWN,
INST, 88|9-DUAL, ANL-CALL, SIREN, and SCAN/
MEM
Connectors and Cables Antenna, Ext.SPKR, Ext.PA, and DC power
Size H 66 mm x W 162 mm x L 100 mm
Weight 1.0 kg
Supply Voltage Nominal 13.8V DC, negative ground (10.8 VDC to
15.6 VDC)
Standard Accessories Mounting bracket and hardware, microphone
hanger, DC cable with fuse