EFJohnson 7780 Two-Way Radio User Manual


 
TRANSCEIVER OPERATION
2-6
November 1999
Part No. 001-7780-500
channel it can be programmed for times from 15
seconds up to 3 minutes, 45 seconds or disabled (not
used). If the transmitter is keyed continuously for
longer than the programmed time, the transmitter is
disabled and an invalid condition tone sounds. Five
seconds before time-out occurs, an alert tone sounds to
indicate that time-out is approaching. The timer and
tone are reset by releasing the PTT switch.
One use of this feature is to prevent a channel
from being kept busy for an extended period by an
accidentally keyed transmitter. It can also prevent
possible transmitter damage caused by transmitting for
an excessively long period. Conventional channels can
also be programmed with the Penalty and Conversa-
tion timers that are described in Sections 2.4.7 and
2.4.8.
2.3.10 TONE ENABLE/DISABLE
The supervisory tones (see Section 2.6) can be
enabled and disabled by the Tones On-Off option
switch if it is programmed. When tones are enabled by
this switch, “TONE ON” is momentarily displayed
and a tone sounds. Conversely, when tones are
disabled, “TONE OFF” is displayed and no tone
sounds. If the Tones On-Off option switch is not
programmed, tones are fixed in the on or off mode by
programming.
2.3.11 SCANNING
Introduction
Scanning cycles through a list of channels, called
a “scan list”, checking each for messages. When a
message is detected that your transceiver is
programmed to receive, scanning stops and the
message is received. Shortly after the message is
complete, scanning resumes (unless it has been
disabled).
There are two basic scan modes: Standard and
Radio Wide. The Standard mode is unique to the type
of channel selected (conventional or SMARTNET/
SmartZone), and the Radio Wide mode is the same
regardless of the channel type selected. Only one of
these scan modes can be enabled at a time. Therefore,
if standard scanning is enabled while radio wide scan-
ning is occurring, radio wide scanning is automatically
disabled and vice versa. More information on these
modes follows.
Standard Scanning
Standard scanning monitors only channels that
are the same type as that currently selected. There-
fore, if a conventional channel is selected, only
conventional channels are scanned, and if a
SMARTNET channel is selected, only SMARTNET
channels are scanned. Standard scanning is turned on
andoffbytheScanoptionswitchasfollows.Ifthis
switch is not programmed, standard scanning is not
available.
To turn standard scanning on, press the Scan option
switch. Scanning is enabled when the “
S
”iconis
indicated in the upper left corner of the display and
SCAN x (conventional) or SCAN ON
(SMARTNET/SmartZone) is briefly displayed. The
“x” is the number of the conventional scan list (1, 2,
or 3) that is selected. Refer to Section 2.4.11 for
more information.
To turn scanning off, press the Scan option switch
again. The “
S
icon is then no longer indicated and
“SCAN OFF” is briefly displayed.
If the zone or channel is changed while scanning is
selected, scanning continues on the same or a
different scan list (see scan list information which
follows).
Radio Wide Scanning
Radio wide scanning monitors the channels in the
preprogrammed radio wide scan list (see information
whichfollows).Thislistmaycontainupto16chan-
nels of any type (conventional or SMARTNET/Smart-
Zone) assigned to any zone. Radio wide scanning is
turned on and off by the Radio Wide Scan option
switch as follows. If this switch is not programmed,
radio wide scanning is not available.
To turn radio wide scanning on, press the Radio
Wide Scan option switch. The icon is then
displayed continuously and “RWS ON” is displayed
briefly.