User's Manual

2. Preliminary Decisions
AMPS EAC-2100 Manual: (Draft, 02/01) Page 2-9
2.4.2 Placement (Continued)
• Isolation: Isolation between the D1 and M1 and between the D1 and M2 antennas must be
at least 75 dB. Isolation between the mobile antenna and all of the others must be at least 60
dB.
Figure 2-3 shows a typical installation. M1 and M2 are placed highest on the tower to
achieve the best coverage to the boosted area. D1 is placed below M1 and M2. At least 25
feet (8 m) of vertical separation is usually needed to meet the isolation requirement.
F NOTE: The isolation achieved at a given separation will vary greatly depending
upon the type of antennas, nearby reflections, etc. Twenty-five feet (8 m) vertical
separation may not be enough in all cases.
D1 must be placed high enough to receive the required minimum signal level from the
donor. The data mobile antenna can usually be placed close to the ground. At least 15 feet
(5 m) vertical separation between the data mobile antenna and the others is usually needed,
however, more may be required in some installations.