User's Manual

MDS 05-2873A01, Rev. A MDS iNet 900 Installation and Operation Guide 21
DRAFT 6—8/29/01
5.2 Antennas
Two antennas are required at repeater stations—one for each radio.
Measures must be taken to minimize the chance of interference between
these antennas. One effective technique for limiting interference is to
employ vertical separation. In this arrangement, one antenna is
mounted directly over the other, separated by at least 10 feet (3 Meters).
This takes advantage of the minimal radiation exhibited by most
antennas directly above and below their driven elements.
Another interference reduction technique is to cross-polarize the
repeater antennas. If one antenna is mounted in the vertical plane, and
the other in the horizontal plane, an additional 20 dB of attenuation can
be achieved. (Remember that the corresponding stations must use the
same antenna orientation when cross-polarization is used.)
5.3 Network Name
The two radios that are wired together at the repeater site must have dif-
ferent network names. To set or view the network names, see “PRO-
GRAMMING” on page 21 and Table 5 on page 26 for details.
5.4 Interface Wiring
A null-modem cable (Figure 11) is required between the COM1 port con-
nectors of the two radios forming a repeater station. This allows them to
freely exchange data even though they are both configured as DCE
devices.
Invisible place holder
Figure 11. Data interface cable wiring for null-modem cable
(used for traditional repeater)
6.0 PROGRAMMING
There are no manual adjustments on the transceiver. Programming and
control is performed remotely, using one of these methods:
• HTTP (Browser) via the iNet 900’s ETHERNET Port
DB-25 DB-25
Spread Spectrum
Master
(DCE)
2
3
7
3
2
7
Spread Spectrum
Remote
(DCE)
TXD
RXD
GND
RXD
TXD
GND
Z? REVISON NEED TO DB-9 CONNECTORS