User's Manual

MDS 05-2708A01, Rev. D MDS TransNET I&O Guide 11
Table 2 lists several types of feedlines and indicates the signal losses (in dB)
that result when using various lengths of each cable at 900 MHz and Table 3
for 2.4 GHz. The choice of cable will depend on the required length, cost
considerations, and the amount of signal loss that can be tolerated.
Antenna System Ground
Precautions should be taken to assure the antenna and its support structure are
bonded to a good earth ground system to minimize the impact of voltages
created by lightning and atmospheric charges.
CAUTION: Safety grounding systems are beyond the scope of this manual. Below you
will find some elementary advice. These are generalities; every location and
installation is unique and requires a unique safety grounding system design.
Please consider consulting a radio system engineer or other professional for
advice or ground system design. A well-designed ground system will mini-
mize risk of electrical shock to personnel and the chances of equipment
damage.
Table 2. Length vs. loss in coaxial cables at 900 MHz
Cable Type
10 Feet
(3.05 Meters)
50 Feet
(15.24 Meters)
100 Feet
(30.48 Meters)
300 Feet
(91.44 Meters)
LMR 400 0.39 dB 1.95 dB 3.9 dB Unacceptable
Loss
1/2 inch
HELIAX
0.23 dB 1.15 dB 2.29 dB 6.87 dB
7/8 inch
HELIAX
0.13 dB 0.64 dB 1.28 dB 3.84 dB
1-1/4 inch
HELIAX
0.10 dB 0.48 dB 0.95 dB 2.85 dB
1-5/8 inch
HELIAX
0.08 dB 0.40 dB 0.80 dB 2.4 dB
Table 3. Length vs. loss in coaxial cables at 2400 MHz
Cable Type
10 Feet
(3.05 Meters)
50 Feet
(15.24 Meters)
100 Feet
(30.48 Meters)
300 Feet
(91.44 Meters)
LMR-400 0.70 dB 3.50 dB 6.61 dB Unacceptable
Loss
1/2 inch
HELIAX
0.35 dB 1.73 dB 3.46 dB 17.3 dB
7/8 inch
HELIAX
0.20 dB 0.99 dB 1.97 dB 9.85 dB
1-1/4 inch
HELIAX
0.15 dB 0.73 dB 1.45 dB 7.50 dB