Page 70 - The Illustrated Dictionary of Electronics

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axial leads • azusa 55

axial leads The centrally located leads emanating azel display A plan-position display that incor-
from the ends of cylindrical components, such as porates two different radar traces on a single
resistors and diodes. cathode-ray tube (CRT), one giving bearing, the
axial ratio The ratio of the minor to major axes of a other elevation.
waveguide’s polarization ellipse. azimuth Also called compass direction. Angular
axis 1. A coordinate in a graphical presentation or measurement in the horizontal plane, clockwise
display (e.g., horizontal and vertical axes in a from north. It is important in radio and television
rectangular coordinate system). 2. The real or communications, navigation, direction finding,
imaginary straight line around which a body ro- land surveying, and radar.
tates, or the line that passes through the center
of a symmetrical arrangement (line of symmetry).
axis of abscissas The horizontal axis (x-axis) of a
rectangular-coordinate graph or screen. Compare
AXIS OF ORDINATES.
axis of imaginaries The vertical axis of the com-
plex plane in which rectangular vectors lie. Com-
pare AXIS OF REALS.
axis of ordinates The vertical (y-axis) of a rectan-
gular-coordinate graph or screen. Compare AXIS
OF ABSCISSAS.
axis of reals The horizontal axis of the complex
plane in which rectangular vectors lie. Compare
AXIS OF IMAGINARIES.
Ayrton-Mather galvanometer shunt A step-
adjustable universal shunt resistor for varying
the sensitivity of a galvanometer. It has the virtue
of keeping the galvanometer critically damped.
The shunt is also useful in multirange
milliammeters, microammeters, and ammeters.
The sensitive meter movement is never without a
shunting resistor during range switching.

azimuth alignment In a tape recorder, the align-
ment of record and playback head gaps so that
their centerlines are parallel.
azimuth blanking In a radar system, blacking-out
of the image as the antenna sweeps across a
specified range of azimuth angles. Effectively
eliminates nuisance echoes from stationary, per-
manent objects (such as tall buildings or commu-
nications towers).
azimuth resolution In a radar system, the mini-
mum azimuth separation of two targets whose
range (distance from the station) are equal that is
required for the system to show two echoes, rather
than one. It is generally measured in degrees.
azusa An electronic tracking system, in which a
Ayrton-Perry winding A noninductive winding single station provides slant range and two direc-
comprising two inductors conducting current in tion cosines for a distant airborne object. This ac-
opposite directions; the opposing flow cancels the curately defines the coordinates of the distant
magnetic field. object in three-dimensional space.