Identifying Your Dvrs Model; Frequency Band Of Operation; In-Band; Table 2 In-Band Dvrs Models - Futurecom Mobexcom P25 Installation & Programming Manual

Identifying Your DVRS Model

Frequency Band of Operation

Depending on the frequency band of operation of the XTL
Subscriber Unit (MSU) and DVR, the DVRS models are classified as follows:

In-Band – when the MSU and DVR operate in the same frequency band.

Cross-Band – when the MSU and DVR operate in two different frequency
bands.

In-Band

The following In-Band DVRS Model Groups are available:
136-174
TM
XTL 2500
TM
XTL 5000
136-174
BAND OF
OPERATION
[MHz]

Table 2 In-Band DVRS Models

The in-band DVRS models are equipped with two sets of filters, which are required in
order to ensure interference-free operation when both the MSU and DVR are
transmitting and receiving simultaneously. The DVR is a full duplex repeater and is
equipped with a duplexer, which provides sufficient isolation to prevent desense during
DVR repeat activation. The DVR duplexer also provides 40 dB isolation on the Mobile
radio transmit / receive frequencies. The filters installed at the output of the MSU are
designed to provide 40 dB isolation on the DVR transmit and receive frequencies.
IMPORTANT
The above filtering isolation must be complemented by 30dB minimum antenna
isolation (between the DVR and Mobile Radio antennas) in order to ensure
interference-free operation. It is recommended that the Mobile antenna is mounted
on the roof of the vehicle while the DVR antenna is mounted on the trunk.
Each DVRS is shipped equipped with custom filters tuned to the specified
frequency bands – note the frequency range specified on the filter Labels.
Programming the DVR / Mobile radio to operate on frequencies outside of the
original specified bands may result in intermittent or complete loss of
communications. Frequency
replacement.
The In-Band DVRS models are also equipped with an RF Bypass Switch, which
bypasses the filtering at the output of the MSU when a "DVR – Disabled" TG is selected
on the O5 / O3 / M5 Control Head.
April 2014
DVRS Installation & Programming Guide – PART I
DVR BAND OF OPERATION
380-430 450-470
380-470 380-470
OR OR
450-520 450-520
changes may
8M083X01 Rev. 16
TM TM
2500 / XTL
[MHz]
764-776
470-512 794-806
380-470 762-776
OR
794-806
450-520
OR
806-825
851-870
require filtering retuning
6881013Y39
5000 Mobile
806-825
851-870
762-776
794-806
OR
806-825
851-870
or
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