User's Manual

Canopy 900 MHz AP and SM User Guide
Issue 2 August, 2004 Page 13 of 16
For this antenna:
Enter this Antenna Gain:
Flat Panel antennas certified with regulatory
agencies by Motorola
10 dBi
Antenna certified by third party
Consult antenna documentation
Leave the External Filters Delay parameter on the AP Configuration page (see Figure 1: Highlights of 900
MHz AP Configuration Page) at the factory default of 0 Nanoseconds, regardless of whether you have
cavity filters. (The External Filter Delay was included in the user interface in case it was needed, but turns
out to never be needed – leave it set to 0.)
Important! To remain within the legal regulatory limits for antenna output power, you must not set the
Antenna Gain parameter lower than the actual gain of your antenna. If you have a 10 dBi antenna, do not
enter an Antenna Gain of 8 or 9. This parameter must be set equal to or higher than the actual gain of your
antenna to remain within the legal regulatory limits for antenna output power.
The parameter has a range from 8 dBi to 32 dBi. When set to 8 dBi, the radio will have a power-out of 28
dBm at the connector, which along with an 8 dBi antenna will generate the legal maximum EIRP of 36
dBm (4 W). When set to 12 dBi, the radio will have a power-out of 24 dBm at the connector, which along
with a 12 dBi antenna will generate the legal maximum EIRP of 36 dBm (4 W).
Note! In some circumstances, it may be advantageous to set the parameter higher than the actual gain of
your antenna. This reduces the power (and range) of the link, and may be useful to reduce RF power levels,
multi-pathing, and jitter in some situations.
Important! When using connectorized antennas, the connector can be a point of failure over time due
to moisture. Accepted industry practices should be used to wrap the connector to prevent water ingress.
The male and female N-type connectors form a gas tight seal with each other, but the point where the cable
enters each connector can be a point for water ingress, with eventual corrosion and failure of the
connection. Wrapping and sealing is critical to long-term reliability of the connection.
One option for a weather-tight wrap around the N-type connector is Coax-Seal, made by Universal
Electronics, http://www.coaxseal.com. Sealing material may also be provided with some antennas.
Start the wrap on the cable 0.5 to 2 inches inches (about 1.5 to 5 cm) from the connection and finish on the
cable 0.5 to 2 inches (about 1.5 to 5 cm) above the connection. See the cable in Figure 1: Highlights of 900
MHz AP Configuration Page. Note this cable has been wrapped, but not yet tied or secured against the
wind. Once done wrapping, squeeze the wrap with your hand or fingers to compress and remove any
trapped air. For abrasion resistance and appearances, premium vinyl electrical tape can be used over the
wrap.
2.7 Spectrum Analyzer
Description
The Canopy 900 MHz SM provides a spectrum analyzer much like 2.4, 5.2, and 5.7 GHz SMs, as shown in
Figure 4: 900 MHz SM Spectrum Analyzer. Due to the heavy general use of the 900 MHz spectrum, it is
advisable to use the SM’s built-in spectrum analyzer or other equipment to confirm the RF environment
both at AP and at SM locations during site surveys.
Operation
On the SM, click on Expanded Stats, then on Spectrum Analyzer. Click Enable several times to scan and
collect data, then click Disable to return the SM to normal mode.