Common features on a marine VHF/DSC radio

The main features that should be on any unit are as follows:

Channel Selector
This will either be a rotary knob or a pair of buttons marked up and down. The channel selector allows the user to change the channel manually.

Power Selection
All VHF radios have a high and low power option. Unless it is a distress situation, it is good practice to use low power on your first attempt to make contact to avoid interfering with other VHF transmissions.

Dual Watch
This allows you to switch between two channels. A Tri Watch allows you to scan between two and three channels, one of which will be Ch16. This is especially useful in busy port control areas where you can listen to Vessel Traffic Services and Ch16.

Scan
Pressing the scan button will start the radio scanning through all channels (or the ones you have preset). When the radio detects a transmission it will stop on that channel to allow user to listen.

Menu
Most radios will have access to some form of menu. Within this there will be lots of options but the most important is access to the DSC function.

On/Off Switch
Often combined with the volume control as a rotary knob.

Squelch Control
This is used to clear weak background signals that come across to interference. By tuning the squelch to the point when the background noise stops you will be able to hear the transmission with a stronger signal.

Distress
The distress button is protected from accidental activation, normal by a bright red spring loaded cover.

End or Clear
This buttons primary function is to cancel DSC alerts.

02/01/2007