Antenna Assembly

These are the parts of the antenna:

· Flat plate antenna

· Antenna pedestal.

Flat Plate Antenna

The flat plate antenna transmits and receives RF pulses.

The flat plate antenna is an array of radiation slots. The RF pulses radiate from each of the slots. The antenna makes a beam 5.4 degrees high and 5.4 degrees wide. The antenna weighs 6 lb (2.7 kg). It is 23 inches wide.

Antenna Pedestal

The antenna pedestal contains these items:

· Scan motors

· Antenna position monitors

· Elevation and scan disable switches.

There is a horizontal scan motor to move the antenna +/- 90 degrees from the airplane centerline. There is also an elevation scan motor to move the antenna +/- 40 degrees up or down. This value includes manual tilt selection from the WXR control panel.

There is a zero position monitor and an incremental monitor for each motor. These monitors send antenna horizontal scan and elevation scan position data to the WXR R/T. There are elevation and azimuth scales that permit a visual measurement of the tilt and scan angles.

There are elevation and azimuth synchros. These synchros send the antenna positions to the WXR R/T. The WXR R/T gets antenna position data from the synchros. The WXR R/T also has a command position. The monitor circuit in the R/T tells when there is a difference between the two values. Then it sets an antenna failure.

There are elevation and scan disable switches on the antenna pedestal. They remove power to the scan and elevation motors. Use these switches to prevent movement of the antenna during maintenance. The switches do not stop RF transmissions from the WXR R/T.

A torque spring in the antenna pedestal balances the weight of the antenna. When you remove the antenna, the torque spring moves the elevation drive to the upper position.

Training Information Point

Use the elevation and scan disable switches for safety to make sure that the antenna does not move while you work on or around it.

WARNING: DO NOT OPEN THE NOSE RADOME IF THE WIND IS MORE THAN 15 KNOTS. IF YOU OPEN THE RADOME IN A WIND, THE RADOME CAN MOVE QUICKLY. THIS CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.

WXR SYSTEM - EFIS CONTROL PANEL - OPERATION

EFIS Control Panel

These are the functions of the EFIS control panel (CP) for WXR control:

· Supplies the on and off control of the WXR R/T

· Enables the navigation displays (ND) to show WXR data

· Supplies the selection of different ND modes

· Supplies the selection of different ranges for WXR data to show on the NDs.

Дата добавления: 2015-10-26