The Panel Setting Tool

There are over 8000 panel adjustment screws on the Green Bank Telescope (GBT), four at each actuator location. The initial adjustment of the surface will include setting the panel to panel heights at each actuator location to a high precision (25 µm or better). It is obviously highly desirable that this operation be performed just once and the panel setting tool has been designed to provide a fast simple way of measuring the panel to panel heights at each actuator. The original concept for the tool is described in "Setting the Panels on the GBT" [GBT Archive Memorandum AS005].

The tool slips over the actuator shaft and four electronic dial indicators make contact with the four panel corners. The panels are identified with a bar code reader. Inclinometers measure the angular position of the actuator shaft. The electronic dial indicators record the panel positions and a data base stored in a small, portable PC. The portable PC (8088 microprocessor) then produces a calculation of how to turn each panel screw by means of a simple program written in BASIC.

A drawing of the tool is shown in Figure 1 and a photograph in Figure 2. The electronic interfacing equipment which allows the portable PC to communicate with the panel setting tool is stored in a large aluminum box. The box is carried along with the panel setting tool from panel to panel. A drawing of the box is shown in Figure 3 and a photograph in Figure 4.

We will supply the antenna manufacturer three of these tools.

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This page was last modified on September 11, 1997.

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