User Manual

76 BTR-30N, TR-30N, TR-32N
Frequency Plan
There are 48 groups in a BTR-30N system. The 48 groups are
divided up into 36 factory-defined groups and 12 user-defined
groups. A group referenced to a base station is comprised of two
TX channels and up to 12 RX channels.
User-defined groups are bl
ank initially and allow the user to
enter their own frequencies.
Factory-defined groups are composed of frequencies that
cannot be modified by the user. The 36 groups are composed of
the following:
Nine (9) Triplet Groups
– Groups 1a to 9c
Nine (9) Single Groups
– Groups 10-18
The factory groups are organized i
n different ways to provide
flexibility to the user on selecting frequencies. A groups is
composed of intermodulation free frequencies. The triplet
groups may be used together for up to three (3) systems that are
intermodulation coordinated. For example, three
intermodulation coordinated systems may be set up by using the
following groups and channels:
• System A = Group 1a, channels: 1, 2, 3, 4
• System B = Groups 1b, channels: 5, 6, 7, 8
• System C = Group 1c, channels: 9, 10, 11, 12
FIGURE 81.
Groups and Tv Channels Used
A group also contains frequencies within different combinations
of the TV channels. The user can select a group clear of
broadcast Tv channels in the area by selecting a group(s) not
using those channels.
Figure 81 indicates how the factory-defined groups used the
three (3) TV channels for TX and three (3) TV channels for
receive. These plans are based upon US broadcast TV channels.
A darkened TV channel indicates the group has frequencies in
the channel. The white TV channel indicates the group has no
frequencies in the channel. For example, Group 1A uses at least
one (1) frequency from each of the three (3) TV channels for
RX and only the 1st TV channel for TX. However, group 18
uses only the 3rd TV channel for TX and RX.
Dark = TV used
Light = TV not used