Abstract: An adaptive canceller construction for cancelling signals received by a radio receiver operating in close proximity to a transmitter having means for extending the usefulness of the device over a wide band of frequencies. The canceller is provided with a memory which will remember the adopted parameter from one time in a given band to the next, so that as a jammer frequency jumps back and forth among several narrow frequency bands, the canceller will jump among a corresponding set of remembered parameters.

Abstract: The disclosed apparatus provides a mercury electrode for making non-destructive tests, especially for Schottky-diode tests of semi-conductors such as silicon. By developing vacuum under a test wafer on a support, a column of mercury is drawn into contact with the test wafer through a bore in the support that accurately establishes the area of the contact. The vacuum system also holds the test wafer securely in position, it avoids spillage of mercury, and additional circuit-completing contact can be made to the wafer with independently controlled pressure.

Abstract: The disclosed apparatus provides a mercury electrode for making non-destructive tests, especially for Schottky-diode tests of semi-conductors such as silicon. By developing vacuum under a test wafer on a support, a column of mercury is drawn into contact with the test wafer through a bore in the support that accurately establishes the area of the contact. The vacuum system also holds the test wafer securely in position, it avoids spillage of mercury, and additional circuit-completing contact can be made to the wafer with independently controlled pressure.