Cisco Aironet 1200 Series Upgrade Manual page 27

Note If your access point contains an internal 2.4-GHz radio card, a
2.4-GHz radio product compliance card should be attached to the
access point.
10. Remount the access point.
11. Install the antenna or external antenna cable (connectorized version
only). If you are installing one antenna, connect it to the connector
marked Right/Primary as shown in this illustration.
Note
5-GHz antennas must be installed. Cisco-approved 5-GHz antennas
are identified by a blue dot on the antenna near the connector or a
blue band on the antenna cable near the connector.
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