Operating Instructions—Type 324
Phase Shift—The change in the phase angle (of a sinusdoidal
waveform) which is introduced when the waveform
passes through a network.
Phosphor—The substance coating the inner face of a
cathode-ray tube. It emits light when bombarded by
electrons.
Plate—In a cathode-ray tube, any one of the deflection
plates.
Preventive Maintenance—Cleaning, inspecting and lubri
cating equipment to insure continued reliable operation.
Probe—A pointed metal tip within an insulating handle.
Used for temporary connecting to a signal source. It can
include attenuation capability. Generally includes the
associated cable and connector.
Probe Tip—That part of a probe which makes contact with
the signal pickoff point.
Pulse Width—The time between specified equal amplitude
points on both slopes of an electrical pulse. Usually
measured at the 50% amplitude points.
Push-Pull—Currents or voltages which are equal in ampli
tude but opposite in polarity. Also defines a circuit
which has that type of response.
Reflection—A signal caused by reflected signal energy.
Usually thought of as energy returned by a transmission
line which is not terminated in its characteristic imped
ance, or which has impedance discontinuities within it.
Response Characteristics—A quantitatitive description of
the input-output characteristics of a device or circuit.
Usually amplitude versus frequency response.
Retrace—Return of the spot to the left of the cathode-ray
tube face upon completion of a horizontal sweep. Also
that portion of the sweep waveform which causes the
spot to return.
Retrace Blanking—The process of creating a CRT blanked
condition during retrace.
Return Trace—A path created by the spot during retrace.
Should not be seen during normal sweep operation.
Ringing—A damped oscillatory transient occurring in a
system as a result of a sudden change of input.
Ripple—AC superimposed on a DC level. Commonly asso
ciated with filtered DC power supplies.
Risetime—The interval between the instants at which the
instantaneous amplitude first reaches specified lower and
upper limits. In the display of a step function of time,
these limits are 10% and 90% of the nominal or final
amplitude of the step.
Rounding—In the display of a step function (usually of
tim e), the loss of the corner following the step.
Sawtooth Waveform—A waveform containing a linear
sloped rise and return to its initial value, the two por
tions usually of unequal duration. Commonly describes
the waveform created by the oscilloscope horizontal
sweep generator.
Semi-Conductor Device—Any one of several devices made
of semi-conductor material; usually diodes or transistors.
Sensitivity—See deflection sensitivity.
Short Circuit—A low impedance connection across circuit
branches or power sources.
Signal Pickoff Point—A point at which a circuit is tapped
into to provide a signal for any of various purposes, such
as oscilloscope display.
Signal Source—The point of origin of a signal. Also used to
describe Signal Pickoff Point.
Slope—In oscilloscope waveform presentations, the term
describes the direction and ratio of change of vertical
deflection related to a change of horizontal deflection
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Source—The point of derivation of power or of a specific
type of power (line, +300 V , —150 V , battery). Also the
element in a Field Effect Transistor which operationally
corresponds with the cathode of triode vacuum tube.
Sweep—An independent variable of a display; unless other
wise specified, this variable is a linear function of time,
but may be any quantity that varies in a definable
manner.
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