User's Manual

Doc. No.
Rev.
Date
1.00
2011-12-08
Damm Cellular Systems A/S, Denmark
TETRAFLEX
®
V7.5 MANUAL - Antenna System for BS41x
TetraFlex® 7.5 Manual 4-6
Cable 2dB loss
450MHz
850MHz
1/4 inch (RFS CF14-50)
21m
15m
3/8 inch (RFS LC38F-50)
27m
19m
1/2 inch (RFS LCF12-50)
42m
30m
5/8 inch (RFS LCF58-50)
55m
39m
1 1/4 inch (RFS LCF114-50)
93m
65m
1 5/8 inch (RFS LCF158-50)
128m
88m
For normal installations 5/8 inch cables or thicker is recommended. When thick cables are
used it is normal needed to have jumper cables in both ends to avoid stress to the connectors
on the antenna and BS.
Cables and connectors between antenna and TMD412/BS41x shall be resistance to water
ingress and migration.
4.1.3 GPS antenna
Each Base Station Controller includes a GPS receiver, which requires an antenna. The GPS
antenna connector delivers +5V for an antenna with built-in amplifier. The GPS antenna
should preferably be mounted on top of the building with good all round vision the whole
horizon. It should NOT be mounted in top of a high mast and should be kept at the greatest
possible distance from any transmit antenna.
The GPS signal is received on 1575.42 MHz with a bandwidth of a little more than 2 MHz
Special care with separation from the TX antenna is important especially, if any transmitter is
located in the range 393.5-394.2 MHz (4
th
harmonic). The current used GPS receiver module
in the BSC411 is a Motorola M12 and in BSC412 it is an iTrax.
Several manufactures have appropriate antennas, which match the receiver. An example is
shown below.
The GPS antenna shall include an amplifier with a gain of about 25dB. As a guideline the
cable loss should not exceed 14 dB, which gives the following maximum cable lengths:
Cable type
14dB
RG223/U
23m
RG214/U
46m
¼ inch (RFS CF14-50)
70m