Motorola VRS750, Service Manual

Page: 33 / 104

21
ICM Transmissions
VRS BASE:
Press the mobile’s PTT to transmit on the frequency corresponding to
the mode shown on the control head’s display. If this mobile’s VRS is
the priority unit (in delay state zero), the VRS unit will then become
non-priority upon the mobile PTT. If you press the mobile’s PTT during
portable-to-base VRS activity, a talk-prohibit tone sounds and the mic
audio is disabled.
VRS BOTH:
Press the mobile’s PTT to transmit simultaneously on the frequency
corresponding to the mode shown on the control head’s display, and
the portable frequency. Use the ASTRO CPS to enable the VRS TX PL
generator option to transmit with the proper PL frequency. If you press
the mobile’s PTT during portable-to-base VRS activity, a momentary
talk-prohibit tone sounds and the microphone audio is disabled.
When using VRS BASE or VRS BOTH mode, all mobile transmissions
are on the mode that is shown on the control head’s display. If the VRS
is currently steering to another mode, that steered mode will be
displayed on the control head. Any mobile transmissions will be on
that new mode until the portable steers the VRS back or the mode
rocker switch is used to change modes. If the mode rocker switch is
used to change modes, the portable user will not be made aware of this
mode change. With Ack Tones are enabled, the portable user will hear
a “bad” tone if the mode is changed during the transmission.
VRS Reception
The VRS option has no effect on mobile radio squelch control or
normal mobile radio reception. The VRS portable unit’s squelch
setting is not user adjustable. Portable audio is heard from the mobile
speaker of the priority VRS unit as shown in Table 5.
Repeated portable transmissions will always be heard from the mobile
speakers.
Portable transmissions without proper PL will only be heard from the
mobile speaker if the microphone is off HUB.
Mobile Audio
Repeat
The VRS transmits to the portable when audio unmutes the mobile
speaker. This allows the user to set the monitor button “on” to defeat
the coded squelch requirements of the mobile radio on a base-to-
portable transmission or “off” to prevent the VRS from repeating
base-to-portable (HUB will also disable this), unless the coded squelch
requirements of the mobile radio are met. Button presses (that is,
Volume , Mode , etc.) on the priority mobile unit will also be
transmitted by the VRS.
Table 5. Portable Audio Heard from Mobile Speaker
Mobile
Microphone
Portable Audio Heard
from Mobile Speaker
On HUB PL*
Off HUB CSQ
* = any valid repeater access PL