GMR648-2CK
| | | | |
• 15 | GMRS / 7 FRS Channels | • Battery Charger |
• 38 | CTCSS Codes | • Battery Level Meter |
• Up to 6 Mile Range* | • Channel Monitor |
• | Internal VOX Circuitry | • | Channel Scan |
• | 5 Selectable Call Tone Alerts | • | Keypad Lock |
• Backlit LCD Display | • | NOAA Emergency / |
• Optional Headset Accessories | | Weather Channels |
• Headset Jack | • Emergency Weather Alert |
• Roger Beep | | |
*Range may vary depending on environmental and/or topographical conditions.
GMR648-2CK RADIO
1 | Antenna | 15 | Call Indicator |
2 | PTT (Push-To-Talk) Button | 16 | Scan Indicator |
3 | Monitor Key | 17 | Channel Indicator |
4 | Call Key | 18 | Alert Indicator |
5 | WX/Alert Key | 19 | Weather Indicator |
6 | Channel/Scan Key | 20 | Transmit Indicator |
7 | Speaker | 21 | Volume Setting Indicator |
8 | Headset Jack | 22 | VOX Indicator |
9 | Up Key | 23 | GMRS/FRS Indicator |
10 | On/Off/Select Key | 24 | Keypad Lock Indicator |
11 | Microphone | 25 | CTCSS Indicator |
12 | Down Key | 26 | Charging contacts |
13 | Battery Level Meter | 27 | Charging LED |
14 | Receive Indicator | | |
Congratulations on your purchase of the Uniden GMR648-2CK (General Mobile Radio Service) radio. This product is a lightweight, palm-sized radio. Use it at sporting events to stay in contact with family and friends, hiking, skiing, outdoors, or in a neighborhood watch for vital communication. This compact, state-of-the-art device is equipped with many features.
PACKAGE CONTENTS
Your package contains two GMR648-2CK radios, two rechargeable NiMH battery packs (#BP38), two AC adapters (#AD-0001), two charging cradles (#RC6488), two belt clips and this reference guide. You may operate the unit using the rechargeable NiMH battery pack or 4 AAA alkaline batteries (not included). The following optional accessories may be purchased by calling the Customer Hotline at 1-800-297-1023 (Mon-Fri 7 am to 7 pm, Sat/Sun/holidays--except Thanks giving and Christmas--9 am to 5 pm, CST). Use only Uniden accessories.
•NiMH Battery Pack - #BP38
•Charging Cradle - #RC6488
•Headset - #HS2467
GMRS LICENSE
The GMR648-2CK radio operates on the General Mobile Radio Service (GMRS) frequencies when using Channels 1-7 and channels 15-22. You must have a GMRS license issued by the Federal Communications Commission to legally use these channels. For licensing information and application forms, visit the FCC online at: www.fcc.gov/wtb/uls or call the FCC hotline at
1-800-418-3676. If you have any questions, you can contact the FCC direct at 1-888-225-5322. No license is required for operation on channels 8-14 or operation on any channel in Canada.
INSTALL THE BATTERY
Your GMR648-2CK radio uses the NiMH battery pack or 4 AAA alkaline batteries (not included).
To install the NiMH battery pack:
1)Make sure your radio is OFF.
2)Remove the battery compartment door by pressing the tab at the bottom of the compartment door allowing the door to be removed.
3)Install the NiMH battery pack into the battery compartment. Be certain to follow the instruction written on the label on the battery pack.
Installing the battery pack incorrectly will prevent the unit from operating.
4) Replace the battery compartment door.
BATTERY LEVEL AND
LOW BATTERY ALERT
This unit has a battery level meter on the display to indicate the status of the batteries. When the battery in
the unit is low, the battery level meter icon 
will flash. Recharge the NiMH battery pack immediately or if you are using the alkaline batteries, you must replace the alkaline batteries in order to continue using the radio.
Warning! To avoid the risk of personal injury or property damage from fire or electrical shock, only use the Uniden accessories specifically designated for this product.
USING THE CHARGING CRADLE
If you use the rechargeable NiMH battery pack, two GMR648-2CK radios can be charged by using the charging cradle.
Make sure to turn the radio OFF before placing the radio in the charging cradle. Otherwise the battery level meter icon won’t indicate properly.
1)Connect the AC adapter (# AD-0001) to DC IN 9V jack and to a standard 120V AC wall outlet.
2)Set the charging cradle on the desk or tabletop, and place the radio in the charging cradle with the keypad facing forward.
3)Make sure that the LED illuminates. Charge the battery pack for 16 hours and remove the radio from the charging cradle after charge.
Note: The charge indicator LED will remain on as long as the radios are left in the charger.
USING THE RADIO
In order to get the most out of your new radio, read this reference guide completely before attempting to operate the unit.
Turning the Radio On and Adjusting the Volume
1)Press and hold the sel/ 
key to turn the radio ON, and increase the speaker volume by pressing the ▲ key. To decrease the volume, press the ▼ key.
2)Press and hold the sel/ 
key again to turn the radio OFF.
Adjusting the Sound (Key Beeps)
Your radio emits a beep each time one of the keys (except for the PTT button and call key) is pressed. To turn this sound OFF, press and hold the call key while turning ON the radio. Repeat this step to turn the sound ON.
Navigating through the Menu
To access the advanced features of the GMR648-2CK, your radio has a Menu function.
Normal 
CTCSS 
VOX Level 
Call Tone 
Key Lock 
Normal
OFF, 1-38 OFF, 1-3 | 1-5 | ON-OFF |
1)To enter the Menu, press the sel/ 
key.
2)Additional presses of the sel/ 
key will advance you through the Menu until exiting to "Normal" operating mode.
3)Other methods of exiting the Menu function are:
a.Press and hold the sel/ 
key again.
b.Press the PTT, mon, call, wx/alert, or ch/scan key
c.Wait 10 seconds until the unit automatically returns to “Normal” mode.
Choosing a Channel
Your radio has 22 channels and 38 CTCSS codes you can use to talk to others. In order to speak to someone, each of you must set to the same channel and CTCSS code.
To choose a channel:
With the radio in "Normal" operating mode press the ch/scan key and press the ▲ or ▼ key to increase or decrease the channel number displayed.
Note: Channels 1-7 have an expectancy range of up to 6 miles. Channels 8-14 have an expectancy range of up to 3 miles. Channels 15-22 have an expectancy range of up to 6 miles. You can know which GMRS or FRS channel is active by the icon. The 
icon indicates scanning GMRS channel,
and the 
icon indicates scanning FRS channel.
Choosing a CTCSS Code
Each of the channels 1-22 may have any one of the codes, OFF or 1-38 selected. Code oF (OFF) indicates no CTCSS code selected and your radio can receive a signal regardless of the code settings of the transmitting radio.
1)Enter the Menu. The CTCSS code on the LCD display will appear.
2)Press the ▲ or ▼ key to increase or decrease the code number displayed. You can also select oF (OFF) at this stage.
3)Exit the Menu.
Talking on Your Radio
To talk to others using the radio:
1)Press and hold the PTT button and speak in a clear, normal voice about 2-3 inches away from the microphone. While you are transmitting, the 
icon will appear on the display. To avoid cutting off the first part of your transmission, pause slightly after pressing the PTT button before you start talking.
2)When you have finished speaking, release the PTT button. You can now receive incoming calls.
While receiving, the 
icon will appear on the display.
Voice Operated Transmission
Your GMR648-2CK radio is equipped with a user selectable Voice Operated Transmitter (VOX) that can be used for automatic voice transmissions. The VOX feature is designed to be used with a headset with a microphone. Transmission is initiated by speaking into the remote microphone instead of pushing the PTT button.
To select the VOX level:
1) Enter the Menu. Advance through the Menu until the vox icon appears on the display. The current level (OFF, 1-3) will be indicated. Level oF (OFF)
disables VOX, while levels 
- 
set the sensitivity of the VOX circuit.
2)Press either the ▲ or ▼ key to the desired VOX sensitivity level. Use level 1 for increased sensitivity to voice in normally quiet environments, and use a higher level to reduce undesired activation in very noisy environments.
3)Exit the Menu.
Transmitting a Call Tone
Your GMR648-2CK radio is equipped with 5 selectable call tones that will be transmitted when the call key is pressed.
To select a call tone:
1) Enter the Menu. Advance through the Menu until the call icon is shown on the display. The current call tone number ( 
- 
) will be indicated.
2)Press the ▲ or ▼ key to increase or decrease the number to the desired call tone. Each tone will be heard through the speaker.
3)Exit the Menu.
To transmit the selected call tone, press the call key. The selected tone will automatically be transmitted for a fixed length of time. Call Tone will be cancelled when the PTT button is pressed.
Channel Scan Feature
Your GMR648-2CK radio has a channel Scan feature that allows you to easily Scan all 22 channels. When an active channel is detected, the radio will pause on that channel until the channel is clear. Then after a 2 second delay, the radio will continue scanning. Pressing the PTT button while the Scan is paused on a channel will allow you to transmit on that channel.
To turn ON channel Scan:
Press and hold the ch/scan key until the scan...
icon is displayed. The channel number on the display will change as the radio rapidly cycles through the channels.
To turn OFF channel Scan:
Press the sel/ 
, call, PTT, or wx/alert key, or press and hold the ch/scan key for 2 seconds.
Key Lock
To lock the keypad:
1)Enter the Menu. Advance through the Menu until
the 
icon appears on the display. The current Key Lock status oF (OFF) blinks on the display.
2)To switch the Key Lock mode from oF (OFF) to on, press the ▲ key.
3)To confirm the setting, press the sel/ 
key. The radio returns to the "Normal" mode.
Note: If you exit the setting mode before confirming your selection by pressing the sel/ 
key, the Key Lock setting will be set to oF (OFF).
To unlock the keypad:
1)Press and hold the sel/ 
key to turn the radio OFF.
2)Press and hold the sel/ 
key again to turn the radio ON. The keypad is unlocked.
Automatic Power Save Feature
Your GMR648-2CK radio has a unique circuit designed to dramatically extend the life of the batteries. If there is no transmission nor an incoming call within 3 seconds, your radio switches to the Power Save mode. The radio is still able to receive transmissions in this mode.
LCD Backlight
The LCD Backlight will automatically turn ON when any key (except the PTT button) is pressed. The LCD display will illuminate for 10 seconds before turning OFF.
Monitor Mode Feature
Your GMR648-2CK radio allows you to listen for weak signals on the current channel at the press of a key.
To turn ON the Monitor Mode:
•Press mon for brief listening, the 
icon will blink.
•Press and hold mon for 2 seconds for continuous listening. The receiver circuit will stay open, and letting in both the noise and weak signals.
To turn OFF Monitor Mode:
Press mon to return to "Normal" mode, and the 
icon stop blinking.
Roger Beep
Roger Beep is a BEEP that is sent to notify the end of transmission (both PTT and VOX transmission). Roger Beep can be heard through the speaker when Key Beep is on. Roger Beep is transmitted even if Key Beep is turned off. However, Roger Beep will not be heard from the speaker.
To turn ON Roger Beep:
Press and hold the ▲ key while turning ON the radio.
To turn OFF Roger Beep:
Press and hold the ▲ key while turning ON the radio.
