Effective area of the antenna of the RT-22 CrAO RI radio telescope

Based on the results of calibrator observations at 13.5-mm and 8.2-mm wavelengths in 1985 and 2005, the dependence of the effective area of the RT-22 CrAO RI antenna on ambient temperature and elevation was determined. The obtained results confirm a high quality of the RT-22 antenna at millimeter wavelengths. A high accuracy of the reflector surface makes it possible to observe at millimeter wavelengths right to 2 mm. At 8.2-mm wavelength, the effective area changes by no more than 5% when the antenna is reinstalled from the zenith to 15° elevation angle. Large antennas, intended to operate at maximum frequencies, should be built either taking into account the climatic conditions of the antenna sites or taking measures to provide thermal stability of the antenna.