These are pictures of the equipment used in the antenna gain calibration project carried out by Jim Gibson and Jack Welch of UC Berkeley in September, 2000. The idea is to use a 5.5x7.5 cm rectangular horn of known gain mounted on the side of one of the HCRO 6m antennas (Antenna 1), and to switch between this horn and the main antenna. The absolute gain of Antenna 1 can then be measured by making interferometric measurememts of a strong source while switching. Once the antenna gain is determined, it can be used to establish the absolute flux of Jupiter. The aim of the project is to determine the antenna gains to an accuracy of ~1%, and then to measure the flux density of primary flux calibrators (mainly planets) to this accuracy.

Click on the thumbnail to see the full picture.
Jim Gibson with the 1cm receiver Waveguide connecting the outside horn to the 1cm receiver Receiver package Receiver Receiver Receiver Receiver Jim with the offset hornOffset hornOffset hornOffset horn