User's Manual

A separate antenna (not included) is necessary for use with the repeater. Typically, a one-
quarter (1/4) wave length antenna maximizes radiation efficiency when installed at the
center of the vehicle roof. If it is necessary to mount the antenna on the vehicle’s trunk
lid, an appropriate 3dB gain antenna should be used. See "Installation," Chapter 4, for
details.
A filter for the battery lines (TLN5277B)is available for use with ASTRO Spectra
mobiles. This filter can be used to prevent excessive alternator whine noise from being
heard on the mobile speaker during VRS operation.
The VRS ships from the factory with the low output power setting at 275mW and a high
output power setting of 2W. The low output power setting is the default setting. We
recommend the LOW Transmit Power setting of 275mW for optimal performance. This
output power provides the VRS with a similar range as the portable when attached to a
mobile antenna. Any deviation from this setting could result in a loss of communication
from the portable to the base.
The Global Tuning Tool (not included) can be used to tune the VRS output power in the
field. For more information refer to “Tuning,” Chapter ?.
VRS Features
The VRS operates with the ASTRO mobile radio and contains the following integrated
features:
o Automatic, multiple-unit, priority-resolution algorithm.
o Portable priority interrupt (PPI) function.
o Conventional/trunked operation.
o Remote switch enable/disable capability for control charger interface.
o Remote activation of emergency alarm feature.
o In-car monitor operation.
o VRS mobile access tones.
o Mobile radio transmitter steering of up to eight modes via Private-Line (PL) code
transmission from the portable radio.
o TX PL generator.
o Base repeater operation for two-frequency, simplex, fixed-repeater systems.
o Mobile audio repeat.
All VRS features can be programmed in the field using ASTRO Spectra mobile CPS.
For more information, refer to “Programming,” Chapter ?.
IMPORTANT NOTE: All ASTRO Spectra VRS systems with the same VRS RF
transmit/receive frequency need to be CPS programmed identically to ensure proper
operation. Failure to do so could result in erratic system operation.
The VRS does not have to be installed in the system for programming - only the mobile
radio is programmed. If the VRS is not connected after programming the mobile system,
an error message "ERR 12/10" will be displayed on the control head.