Bird Technologies 429-83H-01 Series-Manual - Manual (Page 17)

TX RX Systems Inc. Manual 7-9439-6 09/03/09 Page 9
Test Transmission Line
Proper installation of this system requires the
installation of a test transmission line in addition to
the main transmission line for system testing and
diagnostics. The system will operate normally if the
test transmission line is not installed or becomes
damaged, except the base status LED will continu-
ously display an alarm (red) condition. In addition,
one of the display sub-menu’s will show a test
cable not connected message.
Installing the System
Installation of the TTA system should follow the
installation standards listed in Figure 9A and 9B
on pages 10 and 11. Lightning arresters are incor-
porated throughout the system; refer to items 6, 7,
and 11 listed in figure 9. In addition, surge suppres-
sion is also provided for all cable connections
within the tower top box. Proper grounding tech-
niques MUST BE observed for these devices to
perform properly. See the following sections for
specific installation instructions.
Installing the Tower Top Box
Figure 10 shows some of the mechanical features
of the tower top box. Four mounting tabs are
welded to the back of the box to allow for fastening
to the tower. Because of the varied tower types,
the customer must fabricate the interface brackets
between the tower frame and the box. To install the
tower top box perform the following steps.
1) Mount a receiving antenna on the tower.
2) Run the main transmission cable as well as the
test transmission cable up the tower.
3) Mount the tower top box on the tower and con-
nect the antenna feedline, main transmission
line and test line to the box.
4) Connect the tower top box ground lug to a good
solid ground on the tower.
To insure stability, it is important to
fasten the box to the tower using all
mounting tabs. The box must be
mounted with the connectors and
moisture openings facing downward
to prevent water entry. After connecting the main
transmission line, test line, and the antenna feed-
line, we recommend that the connections be tightly
wrapped with rubber splicing tape (see Figure 11).
This will help prevent water entry into the cables.
Start the wraps on the cable several inches away
from the connector and wrap towards the connec-
tor, this will prevent water from seeping in between
the wraps of tape. Cover the connectors com-
pletely with tape.
5) If the tower box door is opened during the
installation it is important to re-tighten the door-
clamp locking screws uniformly so that the door
gasket seal is maintained. Tighten each clamp
about half-way, then start back at the first clamp
and fully tighten each one in the same order.
Tighten with a hand tool only. Insure that the
moisture vent holes at the bottom of the box are
unobstructed.
In-building Lightning Arresters
Two lightning surge suppressors must be installed
in the equipment room one each for the main and
test transmission lines, refer to Figure 9. The fol-
lowing steps are required for proper installation.
1) For the test line install a lightning arrester.
PolyPhaser part # DC50LNZ15MA (N-M/N-F
connectors) or DC50LNZ15 (N-F/N-F connec-
tors). The chassis of the lightning arrester
should be connected to the master ground bus
with a pigtail.
2) For the main transmission line install a lightning
arrester TXRX part # 8-21550. This device is
NOTE
Mounting Tabs
.312 Dia Thru
Mount Holes
4 Places 6.69"
12.00"
Figure 10: Tower-top box mechanical details.