User's Manual

Operation GMH Series VHF Radio
Page 3-8 BK RADIO
Priority Mode C
In priority mode C the priority channel is pre-programmed. This channel is displayed any time
PRI is on, no matter where the Channel Select knob is set. Priority operation during scan
operation is the same as with Priority Mode A, except that the priority channel is pre-
programmed, not the selected channel. In priority mode C the transmitter always transmits on
the priority channel when PR is on.
Priority Mode D
Priority mode D operates exactly like priority mode C. However when PRI is on, the channel
name or number displayed is the knob-selected channel, not the fixed priority channel.
BUSY CHANNEL
If your radio has been programmed by your dealer for busy channel operation, it will operate in one of
the following three modes.
Busy Channel Indication
The yellow Busy Channel Indicator glows if there is carrier activity on the channel selected. If
the channel selected is a Code Guard channel and the correct code is not detected, the Busy
Channel Indicator remains on for the duration of the carrier activity and no messages are
heard. During Channel Scan and Priority Scan operation, the Busy Channel Indicator glows
when activity is detected on any channel that is on the scan list. When scanning Code Guard
channels, with the CG button on, and activity has been detected, the Busy Channel Indicator
glows for the time period necessary to determine if the proper Code Guard has been
received, causing the Busy Channel Indicator to flash at various rates. In Priority Scan
operation, with the CG button on, the Busy Channel Indicator remains on for the duration of
the carrier activity.
Busy Channel Lockout
The Busy Channel Lockout feature applies only to those channels programmed for receive
Code Guard operation. When carrier activity is detected on the channel selected, the radio
checks the receive Code Guard value. If the proper Code Guard value is present, the radio
can transmit on that channel, even if the CG button is not on. If the radio detects an incorrect
value or carrier activity only, the transmitter is disabled, an alert tone is heard, and the display
shows the word "Busy" when the PTT is pressed, regardless of whether the CG button is on
or off.
Channels not programmed for receive Code Guard operation transmit regardless of carrier
activity.
Busy Channel Lockout Override
This mode operates in the same manner as Busy Channel Lockout with the exception that
the user can override and transmit by pressing the CG button.