TransCore Amtech IT2200, Installation Maintenance And Service Manual

Page: 99 / 204

Tuning the Lane
5-9
Figure 5-4 Ranges of RF Attenuation Statistics
9. Select a pair of attenuation settings that give acceptable attenuation response
counts. (Do not use 15dB attenuation.) Attenuation settings close to 8dB
downlink and 12dB uplink are typical in many installations. In Figure 5-3,
settings of 13dB downlink and 7dB uplink are an acceptable choice.
Check Tag Test
The check tag works best if the check tag antenna whip is placed directly in front of
the active elements of the transmit antenna. If a UTA or beacon antenna is used for the
transmit antenna, the patches on the antenna lie directly down the center of the
radome, equidistant from the long edges. If the check tag antenna is mounted on the
same rail as the transmit antenna, the check tag antenna should be rotated down so that
the whip is directly in front of the center of the transmit antenna radome. This is a
good approximation for the check tag antenna placement. Ensure that the uplink and
downlink RF power levels are set at the lane tuning levels previously set in the Lane
Tag Test.
IT2000 Check Tag Test
This test verifies that the IT2000 check tag and check tag antenna are working cor-
rectly.
Acceptable RF
Attenuation
Settings Marginal RF
Attenuation
Settings Unacceptable
RF Attenuation
Settings