
Operating Instructions—Type 324
Bandwidth—The frequency range through which a circuit
will provide an output which is at least 0.707 times the
voltage output provided at a reference frequency within
said range. The limits are referred to a "Half Power", or
" —3 dB Points." The lower frequency lim it is under
stood to be DC if only one value is given.
Beam—The electron beam emitted by the cathode of a
CRT. Its impinging on the phosphor creates the light on
the face of the cathode-ray tube.
Bezel—The flange or cover which holds the external grati
cule, light filter, viewing hood, etc. in front of the
cathode-ray tube face.
Blanked—Condition under which the electron beam is pre
vented from striking the cathode-ray tube face.
Blanking—The process of creating the blanked condition.
Blooming—An increase in display size accompanying an
increase in CRT IN T E N S IT Y setting.
Calibration—Process whereby an instrument is adjusted to
perform within specified limits.
Characteristic Impedance—An ohmic value which expresses
an electrical quality of a transmission line or cable. It is
the impedance the line would present if it were of infin
ite length.
Circuit Board—Any of various boards on which are
mounted circuit components and interconnections. The
circuit board is usually fastened to a chassis with screws
or clips.
Compression (Display)—An increase in the deflection
factor, usually as the limits of the quality area are ex
ceeded.
DC Balance—The condition existing in the Type 324
Oscilloscope when, with the vertical input grounded, no
trace shift occurs as a result of any change in vertical
deflection factor.
DC Coupling—The condition existing when no capacitor
interrupts the path between the signal take-off point and
the oscilloscope circuit to which the signal is applied.
DC Reference Position—The position on the oscilloscope
graticule which is occupied by the trace when the input
is grounded. Normally refers to the vertical circuit, but
also pertains to the horizontal circuit during EXT
H O R IZ operation.
Decoupling—The process of removing AC signals or tran
sients from the power supply voltages applied to a cir
cuit. Usually refers to shunting AC and transient signals
to ground by connecting a capacitor from the decoup
ling point to AC ground, and an impedance between the
power supply and the decoupled point.
Deflection Blanking—Blanking by means of a deflection
structure in the cathode-ray tube electron gun which
traps the electron beam inside the gun to extinguish the
spot, permitting blanking during retrace and between
sweeps, regardless of intensity setting.
Deflection Factor—The ratio of the input signal amplitude
to the resultant displacement of the indicating spot
(volts/div).
Deflection Plates—Metal plates contained within a cathode-
ray tube. Application of voltage to these plates creates
an electrostatic field which controls horizontal, vertical
or blanking deflection of the electron beam.
Deflection Polarity—The relation between signal polarity
and spot displacement direction. The Type 324 Oscillo
scope has a positive deflection polarity, indicating up
ward and right deflection in response to + vertical and
horizontal input signals, respectively.
Deflection Sensitivity—The div/volt ratio which describes
the amount of deflection resulting from a unit of applied
signal.
Differential Am plifier—An amplifier whose output signal is
proportional to the algebraic difference between 2 input
signals.
Differential Signal—The instantaneous algebraic difference
between two signals.
Display—The visual presentation created by the electron
beam on the face of a cathode-ray tube.
External Horizontal Signal—Any signal applied to the Type
324 Oscilloscope T R IG OR H O R IZ IN PU T connector
for purposes of EXT T R IG oscilloscope operation.
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