User's Manual

154 Mercury Reference Manual 05-4446A01, Rev. C
cable at 3650 MHz. The choice of cable depends on the required length,
cost considerations, and the acceptable amount of signal loss.
The tables below outline the minimum lengths of RG-214 coaxial cable
that must be used with common GE MDS omnidirectional antennas in
order to maintain compliance with FCC maximum limit of +36 dBi. If
other coaxial cable is used, make the appropriate changes in loss figures.
NOTE: The authority to operate the transceiver in the USA may be
void if antennas other than those approved by the FCC are
used. Contact your factory representative for additional
antenna information.
5.1.5 Conducting a Site Survey
If you are in doubt about the suitability of the radio sites in your system,
it is best to evaluate them before a permanent installation is underway.
You can do this with an on-the-air test (preferred method), or indirectly,
using path-study software.
An on-the-air test is preferred because it allows you to see firsthand the
factors involved at an installation site, and to directly observe the quality
of system operation. Even if a computer path study was conducted ear-
lier, perform this test to verify the predicted results.
Perform the test by first installing a radio and antenna at the proposed
Access Point (AP) station site (one-per-system). Then visit the Remote
site(s) with another transceiver (programmed as a remote) and a
hand-held antenna. (A PC with a network adapter can be connected to
each radio in the network to simulate data during this test, using the
PING command.)
With the hand-held antenna positioned near the proposed mounting
spot, a technician can check for synchronization with the Access Point
station (shown by a lit
LINK LED on the front panel), then measure the
reported RSSI value. (
See Antenna AimingFor Directional
Antennas on Page 144 for details.) If you cannot obtain adequate signal
Table 5-1. Length vs. Loss in Coaxial Cables at 3650 MHz
Cable Type
10 Feet
(3.05 m)
50 Feet
(15.24 m)
100 Feet
(30.48 m)
500 Feet
(152.4 m)
RG-214 .76 dB 3.8 dB 7.6 dB Unacceptable
Loss
LMR-400 0.39 dB 1.95 dB 3.90 dB Unacceptable
Loss
1/2 inch HELIAX 0.23 dB 1.15 dB 2.29 dB 11.45 dB
7/8 inch HELIAX 0.13 dB 0.64 dB 1.28 dB 6.40 dB
1-1/4 inch HELIAX 0.10 dB 0.48 dB 0.95 dB 4.75 dB
1-5/8 inch HELIAX 0.08 dB 0.40 dB 0.80 dB 4.00 dB