Uniden UM425 VHF DSC 사용자 설명서

Due to its rugged design, the UM425 requires very little maintenance. Howev-

er, it is a precision electronic instrument, so you should follow a few precau-

tions:

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.

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 57).

Make sure you are transmitting at the correct 

power level for this channel (see the channels and 

frequency tables starting on page 57).

Make sure the duration of each transmission is 

less than 5 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 UIC channel settings (see Setting the 

UIC channel mode (USA/CAN/INT) on page 12).

I can’t read the display.

Adjust the contrast and backlight brightness level 

(see page 22)

The display is too bright at 

night.

Adjust the backlight brightness level.

(see page 22)

I can’t see any words on the 

display.

Reset the radio back to the default contrast level: 

turn off the radio; hold the menu key and turn it 

back on.

UM425 VHF OM.indd   51

28/9/11   11:55:22 AM