Specifications

If a channel with no busy tone is found, the portable
transmits a burst of busy tone to acquire the repeater. The
repeater then responds with a burst of acquisition tone. Upon
receipt of the acquisition tone, the portable proceeds to
transmit the group tones (either two or four tones). If a four
tone sequence is sent, the portable must detect all four tones
and busy tone before entering the Ready Mode. If a two tone
sequence is sent, the busy tone must be present within 90
milliseconds of the last tone in order for the radio to enter
the Ready mode. If no busy tone is present, or if the four tone
sequence isn’t valid, the portable will jump to the next
channel in the call originate set and check for busy tone as
described above.
READY MODE (Figure 10 on page 21)
When an incoming call has been detected, or an idle
channel has been acquired, the portable enters the Ready
mode. In this mode, the audio and push-to-talk circuits are
enabled, the speaker is unmuted, and the operator is alerted
an alert tone. The radio can then be used in the conventional
push-to-talk manner with the radio remaining on the channel
until the operator hangs up or the repeater drops the busy
tone, causing the unit to revert to Idle mode.
CONVENTIONAL SYSTEM
DESCRIPTION
In conventional mode (not trunked) the radio can oper-
ate either with tone Channel Guard, digital Channel Guard,
or carrier squelch; depending on personality programming.
Tone Channel Guard range is 67.0 to 210.7 Hz. Squelch Tail
Elimination (STE) is used with tone Channel Guard to elimi-
nate squelch tails at the receiving radio by phase shifting the
transmitted Channel Guard tone when the PTT is released.
NOTE
If a call is initiated and a sequence of five beeps is
sounded, the user cannot access the radio system
due to being out of portable receive range or being
inoperative. Any subsequent call will be ignored for
20 seconds.
LBI-38836B
18