Operator's Guide

handset
A held-held device that is used to control the functions of a radio. It most commonly consists
of an earpiece, microphone and PTT button. A handset may also have a display and a
keypad.
HF network
The part of the radio configuration that defines specific details for making calls using Codan
Selcall, 2G ALE or 3G ALE.
macro
A set of instructions to automate a task you perform with the radio. When a macro is
assigned to a key, the key can be used to execute the task quickly.
PTT button
The Press-to-talk button is located on the left side of the handset. This button switches the
radio to transmit mode for analogue and digital voice communications, switch mute off
temporarily. Push-to-talk can also cancel voice calls prior to the point where voice can be
transmitted, cancel calls where data is being transmitted, and exit out of editable screens
without saving changes.
RFU
The unit in a radio that modulates audio signals onto radio frequencies that can be
transmitted on air, and that demodulates the radio frequencies it receives into audio signals.
standing wave ratio (SWR)
The ratio of maximum and minimum voltages on a transmission line of the starting wave
resulting from the interaction of the forward and reflected waves. It is a measure of how well
the antenna matches the radio output.
station
A radio in an HF network used for communications.
Definitions
Page 64 Sentry-H 6110-MP Operator Guide