1-17
DEFLECTION PLATES—Two pairs of parallel electrodes, one pair set forward of the other and at right
angles to each other, parallel to the axis of the electron stream within an electrostatic cathode-ray tube
[6].
DEGENERATION—The process whereby a part of the output signal of an amplifying device is returned to
its input circuit in such a manner that it tends to cancel part of the input [7].
DEGENERATIVE FEEDBACK—Feedback in which the feedback signal is out of phase with the input
signal; also called NEGATIVE FEEDBACK [8].
DEGREE-OF-FREEDOM—The number of axes about which a gyro is free to precess [15].
DEIONIZATION POTENTIAL—The potential at which ionization of the gas within a gas-filled tube
ceases and conduction stops; also referred to as extinction potential [6].
DEIONIZATION TIME—In a spark gap, the time required for ionized gas to return to its neutral state
after the spark is removed [18].
DELTA—A three-phase connection in which windings are connected end-to-end, forming a closed loop
that resembles the Greek letter delta. A separate phase wire is then connected to each of the three
junctions [5].
DEMODULATION—The removal of intelligence from a transmission medium [12].
DEMODULATOR—A circuit used in servosystems to convert an ac signal to a dc signal. The magnitude
of the dc output is determined by the magnitude of the ac input signal, and its polarity is determined by
whether the ac input signal is in or out of phase with the ac reference voltage [15].
DeMORGAN'S THEOREM—A theorem which states that the inversion of a series of AND applications is
equal to the same series of inverted OR applications, or the inversion of a series of OR applications is
equal to the same series of inverted AND applications. In symbols,
DENSITY—(1) The compactness of a substance. (2) Mass per unit volume [10].
DEPLETION REGION—The region in a semiconductor where essentially all free electrons and holes
have been swept out by the electrostatic field which exists there [7].
DEPOT-LEVEL MAINTENANCE (SM&R CODE D)—Supports SM&R Code I and SM&R Code O
activities through extensive shop facilities and equipment and highly skilled personnel [14].
DESIGNATION—Operational phase of a fire-control or track radar during which the radar is directed to
the general direction of a desired target [18].
DETECTION—The separation of low-frequency (audio) intelligence from the high-frequency carrier [17].
DETECTOR—A mixer or converter in a superheterodyne receiver [18].
DICE—Uncased chips [14].
