Main Glossary Index
Number Index Page
A Index Page
B Index Page
C Index Page
D Index Page
E Index Page
F Index Page
G Index Page
H Index Page
I Index Page
J Index Page
K Index Page
L Index Page
M Index Page
N Index Page
O Index Page
P Index Page
Q Index Page
R Index Page
S Index Page
T Index Page
U Index Page
V Index Page
W Index Page
X Index Page
Y Index Page
Z Index Page

 RadioShack Consumer Electronics Glossary: P

Electronics: see Power.
Measurement: see Peta- (P-).
Acronym: Peer-to-Peer
Internet: A type of file-sharing network that allows users with the same networking software to access the contents of a specified area on each other's hard drives.
Telephony, Computers: A piece of a information transmitted over a packet-switched network.
Packet-switched Network
Telephony, Computers: A communications system that breaks each individual transmission or telephone call into packets, which are sent separately. Packet-switched networks are slower, but more efficient than circuit-switched networks.
Telephony: A message that is broadcast from a group of cell sites that carries a mobile ID, for the purpose of alerting the cellular telephone that a call is waiting.
Digital Video: A thumbnail of all of the colors that are available to a computer or device, that allows the user to chose which colors are available for the computer to display. The greater the number of colors, the larger the data file becomes and more processing time is required to display your images. For example, if the system uses 24-bit color, then over 16.7 million colors are included in the palette.
Acronym: Phase Alternated by Line / Sequential Couleur Avec Memoire (French: Sequential Color with Memory)
Video: A color television standard or timing format that was developed in West Germany to correct some of the color inaccuracies in NTSC and which is used by most other countries in Europe, including the United Kingdom but excluding France, as well as Australia and parts of the Far East. PAL/SECAM uses a total of 625 horizontal lines per frame. Each field refreshes at 50 Hz. PAL encodes color differently from NTSC.
Panel Meter
Electronics: A measurement device or display that is designed to be installed into another device or circuit, rather than being a stand-alone component. 
Digital Video: An extremely wide-view image created by capturing a series of images.
Audio: A material traditionally used for cone construction. Paper are economical to product and provide a wide range of mechanical properties. The disadvantage to paper cones is that they are very sensitive to environmental conditions. Humidity particularly affects paper cones.
Electronics: A method of making multiple electrical connections in which all of the positive leads are connected to one power terminal and all of the negative leads are connected to the other power terminal, so that the current has multiple paths to follow through the circuit. Compare to Series.
Computers: A low-speed PC computer connection that is commonly used for printers. Macintosh« computers do not have parallel connections.
Parallel Port
Computers: A port on PC computers that is faster than a serial port but slower than SCSI, USB, or IEEE 1394 ports.
Partial Obscuration see Obscuration, Partial.
Measurement: A unit of pressure (in audio, a 1 kHz signal at 94 dB SPL). Named for Blaise Pascal.
Weather: the unit of pressure produced when one newton acts on about one square meter.
Computers: A programming language invented by Niklaus Wirth.
Pascal's Law
Weather: when an external pressure is applied to any confined fluid at rest, the pressure is increased at every point in the fluid by the amount of external pressure applied. It means that the pressure of the atmosphere is exerted not only downward on the surface of an object, but also in all directions against a surface which is exposed to the atmosphere. Formulated by blaise pascal (1623-1662), a french mathematician, theologian, and physicist.
Passive Component: see Component, Passive.
Passive Filter: see Filter, Passive.
Passive Noise Reduction: see Noise Reduction, Passive.
Patch Cable
Computers, Networking, Cables: A short length of cable used to connect two devices together.
Video: A movie or other special programming event that must be purchased individually.
Video: The color difference between the blue component and the luma in the Y'Pb'Pr color space. Also called B' - Y, and often abbreviated to Pb (without the apostrophe).
Acronym: Private Branch eXchange
Telephony: A telephone system (often used in businesses) that allows multiple telephones to be connected to a smaller number of telephone lines.
Acronym: Printed Circuit Board
Electronics: A component used for building circuits in electronic kits.
PC Card: see PCMCIA Card.
Acronym: Pulse Code Modulation
Telephony: A method of modulating an analog signal that is sampled periodically, quantified and transmitted as a digital binary code. Commonly used with T-1 and T-3 carrier systems.
Audio, Video: A lossless audio encoding scheme used by audio CDs and DVD-Audio. This encoding method maintains the highest fidelity sound. Compare to
Acronym: Personal Computer Memory Card International Association
Electronics, Computers: An international organization that is responsible for establishing PC card standards.
Acronym: Personal Computer Memory Card International Association Card
Electronics, Computers: A credit card-sized device that can be a flash memory card, a network card, a modem or even a hard drive.
PCMCIA Adapter
Electronics, Computers: A device that allows the use of other memory cards in a PCMCIA slot. The adapter accepts the smaller memory card and transfers its connections to a standard PCMCIA connection.
Acronym: Personal Communications Service
Telephony: A telephone service that operates on the 1.9 GHz band, with a 120 MHz wide spectrum . It is licensed as two 30 MHz segments for the 51 major trading areas, and three 10 MHz segments for the 493 basic trading areas.
Acronym: PC Paintbrush
Digital Video: A lossy file format that supports RGB, indexed-color, gray scale, and bitmap color modes.
Acronym: Personal Digital Assistant or Personal Data Assistant
Electronics, Computers: A hand-held mobile device that provides at least limited computing functions and significant information storage and retrieval capabilities. PDA's are most often used for maintaining calendars, to-do lists and address book information.
Acronym: Personal Digital Cellular
Telephony: The cellular standard in Japan, based on the TDMA standard.
Acronym: Portable Document Format
Computer, Internet: A proprietary file format created by Adobe« that allows documents created in any application to be viewed, shared or printed on any computer platform.
Audio: The thermal capacity of a speaker driver in watts.
Audio: The maximum power output (for amplifiers) or input (for speakers). Exceeding the peak input or output power can damage the amplifier, speaker or both.
Electronics: The maximum or highest amplitude level of a signal or parameter. For example, Peak Wattage is the absolute maximum wattage that a device either draws or can provide.
Telephony: That part of the business day in which cellular customers pay full service rates.
Peak Inverse Voltage: see PIV.
Peak to Peak
Electronics: The difference between the maximum positive and the maximum negative values of an AC waveform.
pebi- (Pi-)
Measurement, Computers: New SI / Metric unit of binary measurement, not yet fully adopted, equal to 250 or 1, 125, 899, 906, 842, 624.
Peer-to-Peer: see P2P.
Personal Communications Service: see PCS.
Personal Computer Memory Card International Association: see PCMCIA.
Personal Data Assistant: see PDA.
Personal Digital Assistant: see PDA.
Personal Digital Cellular: see PDC.
Personal Handyphone System: see PHS.
Personal Information Manager: see PIM.
peta- (P-)
Measurement: SI / Metric unit of decimal measurement, equal to 1015 or 1,000,000,000,000,000.
Measurement, Computers: Unit of binary measurement, equal to 250 or 1, 125, 899, 906, 842, 624.
DIY, Electronics: 0.000000000001 farad. See pico- and farad.
Phantom Power
Audio: A method of providing power to microphones by applying a voltage to the same wires that carry the audio signals.
Electronics, Plug 'n Power: The name given to an electrical circuit of a building. Most houses have two phases, each being 110V. About half the lights and outlets are on each phase. 
Phase Coupler (Signal Bridge)
Electronics, Plug 'n Power: A device that connects two 110V phases together so that the Plug 'n Power X-10 signal can cross from one to the other. This allows Plug 'n Power units to work with each other even though they are on different phases.
Phase Locked Loop: see PLL
Phase Response: see Response, Phase.
Audio, Turntables: The low-level output signal from a turntable..
Audio, Connectors: see RCA Connector.
Photocell, CdS: see Photovoltaic Cell.
Digital Video: A small area on the surface of an image sensor that captures the brightness for a single pixel in the image. There is one photosite for every pixel in the image.
Photovoltaic Cell
Electronics: A component used to convert light energy into electrical energy. Also called a Solar Cell or Photocell.
Acronym: Personal Handyphone System
Telephony: The cordless telephone standard in Japan.
Mathematics: The mathematical constant equal to the ratio of the circumference of a circle to its diameter. Pi is approximately 3.14.
Pi-: see Pebi- (Pi-).
Acronym: Pulse Indication
Metal Detectors: A metal detector with a transmitter circuit that pulses an electric current into the ground before quickly shutting down. The eddy currents dissipate immediately from wet salt sand and other ground minerals because they are poor conductors. Because they are better conductors, metals hold the eddy currents, and when the receiver circuit comes on, it picks up the returning signals from metal objects.
Telephony: A wireless base station with extremely low output power designed to cover an extremely small area, such as one floor of an office building.
pico- (p-)
Measurement: SI / Metric unit of decimal measurement, equal to 10-12 or 0.000000000001.
Acronym: Picture File Format
Digital Video: A graphics file format used primarily on Macintosh computers.
Picture-In-Picture: see PIP.
Electronics: Refers to a device that operates using a piezoelectric crystal.
Piezoelectric Crystal
Electronics: A crystal material that will generate a voltage when mechanical pressure is applied and undergo mechanical stress when subjected to a voltage.
Piezoelectric Effect
Electronics: The production of a voltage between opposite sides of a piezoelectric crystals as a result of pressure or twisting. Also the reverse effect that the application of a voltage to opposite sides causes a deformation to occur at the frequency of the applied voltage. This effect is used to converts mechanical energy into electrical energy and vice versa.
Acronym: Personal Information Manager
Electronics, Computers: A device or software package designed to organize personal information, such as a calendar, to-do list and address book.
Digital Video: A distortion effect that occurs with telephoto zoom, in which straight lines at the edges curve in toward the far corners.
Metal Detectors: Finding the exact target location with respect to a search coil's designated center. Accomplished by interpreting the centers of audio response width in perpendicular directions or scans. See also Detuning.
Acronym: Picture-In-Picture
Video: A television feature that allows you to view one channel in an inset box while another channel is displayed on the main screen.
Passive Infra Red
Security: A type of motion detector that uses a passive infrared receptor to detect motion.
Audio, Video: Refers to illegal copies of intellectual property, the act of creating such copies, a person or organization that creates such copies or a web site or other location providing such copies (whether the copies are provided for free or for profit).
Acronym: Peak Inverse Voltage
Electronics: The maximum rated value of a AC voltage acting in the direction opposite to that in which a device is designed to pass current.
Acronym: shorthand for Picture Element
Digital Video: An individual element of either a CCD sensor or a digital image. A pixel is a single color point in a display. The higher the number of pixels in a display, the higher the picture quality will be.
Digital Video: An effect seen when you enlarge a digital image too much and the pixels become obvious. See also Jaggies or click here for an illustration.
Audio: A file system for digital audio players that organizes the songs to be played according to the users preferences. A playlist can be either pre-generated, as in a radio station's programming, or custom-created by an individual user.
Audio, Turntables: The rotating part of the turntable on which the record is placed.
Cables: An air-return area in a HVAC (Heating Ventilation Air Conditioning) system. Plenum is not a type of cable coating or insulation; a "plenum cable" is a cable rated for use in a plenum area.
Acronym: Phase Locked Loop
Communications:An electronic circuit that uses either a voltage-controlled or current-controlled oscillator to match a particular frequency for greater stability in either reception, transmission or manipulation of a radio signal. This circuit allows greater precision and accuracy of tuning compared to a VFO (Variable Frequency Oscillator).
Plug 'n Power
Electronics: The name given to RadioShack's system of home automation products. 
Computer, Electronics: An add-on piece of software or hardware for a device or computer program.
Electronics, Plug 'n Power: A module or controller that is plugged into an outlet of the existing electrical system of a building.
Acronym: Portable Network Graphics
Digital Video: A compressed image file format similar to JPG.
PNP Transistor: see Transistor, PNP.
Point and Shoot
Digital Video:: A simple, easy to use camera with a minimum of user controls and automatic control of most functions.
DIY, Electronics, Batteries: 1) Having a fixed direction of current flow, from a positive terminal or lead to a negative terminal or lead.
2) An electrical condition determining the direction in which current tends to flow.
3) Having two opposite charges.
Electronics, Communications: The alignment or orientation of the waves of a signal (either circular or linear).
Polar Pattern
Audio: The graphic representation of the sensitivity of a microphone over all angles at a rated frequency. Examples of polar patterns are Omnidirectional, Cardioid, Hyper-cardioid and Ultra-cardioid. "0" represents the direction in which the microphone is pointed.
Omnidirectional Polar Pattern
Cardioid Polar Pattern
Hyper-cardioid Polar Pattern
Ultra-cardioid Polar Pattern
Polar Regions
GPS, Satellite: Consists of two areas; the southernmost area of the earth which is centered upon the South Pole, and the northernmost area which is centered upon the North Pole.
Electronics: A thermoplastic material composed of polymers of ethylene.
Electronics: A chemical compound formed by polymerization, resulting in the union of monomers (smaller chemical units) or the continued reaction between polymers with a lower molecular weight.
Electronics: The process by which monomers (smaller chemical units) are combined to form a polymer.
Audio: A cone material which provides a smooth frequency response of moderate range. Polypropylene provides consistent performance and is not easily affected by humidity.
Electronics: A plastic made by the polymerization of high-purity propylene gas in the presence of an organometallic catalyst at relative low pressures and temperatures.
Electronics: A thermoplastic produced by the polymerization of styrene (vinyl benzene).
Polyvinyl Chloride: see PVC.
Audio: Popping is the noise that is associated with vocally induced distortion in a microphone due to the hard sound of consonants like "b" or "p". When a microphone is used to capture vocals, either sung or spoken, the air burst that is produced heads straight for the unprotected microphone and can cause overload distortions in the microphone and any linked electronics. A windscreen placed on the microphone can correct this problem.
Audio: A hole or tube connecting the inside of a speaker enclosure with the outside of a speaker enclosure. Also called a Vent.
Computers: A connection point on the computer that accepts a cable, allowing communication between the computer and another device.
Ported Speaker: see Enclosure, Vented.
Computers: A print mode where the image or text is printed normally, on 8.5 x 11 inch paper, as opposed to Landscape, where the image is printed sideways.
Digital Video: An image taken with the camera held sidewise to obtain an image taller than it is wide, as opposed to Landscape, where the camera is in its normal horizontal orientation.
GPS: An exact, unique location based on a geographic coordinate system.
Positive Ground: see Ground, Positive.
Positive Response: see Response, Positive.
Pot: see Potentiometer.
Potential Difference
DIY, Electronics: A voltage difference between two points that will cause current to flow in a closed circuit.
Potential Energy
Electronics: A type of energy that has potential to do work because of its position relative to others.
Electronics: A variable resistor with three terminals, a resistor and an actuator (the adjustment shaft or dial) that is used to tune a circuit by changing the resistance and potential when the actuator is adjusted. For example, volume controls are usually potentiometers. Also called a Pot. There are several types of potentiometer, described by function, actuator type, resistance material, configuration and type, as shown below.
Function Antilog (Taper), Audio (Taper), Linear (Taper), Trimmer
Actuator Rotary, Linear (Slide)
Resistance material Carbon, Cermet, Conductive Plastic, Wirewound
Configuration Single-gang, Dual-gang, Dual-concentric
Type Single-turn, Multi-turn, Linear (Slide)
Potentiometer, Antilog (Taper)
Electronics: A potentiometer in which the increase in resistance is logarithmically proportional to the rotational change, with resistance increasing slower than the rotational change. Originally, antilog potentiometers were used in balance controls that had a log/antilog dual section potentiometer (or dual gang potentiometer); however, they are rarely used in modern electronics. Also called a Reverse Audio Taper Potentiometer. Compare to Audio Taper Potentiometer and Linear Potentiometer.
Potentiometer, Audio (Taper)
Electronics: A potentiometer in which the increase in resistance is logarithmically proportional to the rotational change, with resistance increasing faster than the rotational change. Compare to Antilog Taper Potentiometer and Linear Potentiometer.
Potentiometer, Carbon
Electronics: A potentiometer with a carbon composition ink resistance element on an insulating body. This is the most basic form of potentiometer construction.
Potentiometer, Cermet
Electronics: A potentiometer with a metallic resistance element on a ceramic substrate, normally used for trimmer potentiometers.
Potentiometer, Conductive Plastic
Electronics: A potentiometer with a resistance element composed of a conductive plastic with well-defined resistance characteristics, normally used for high-quality linear (slide) potentiometers and rotary potentiometers.
Potentiometer, Dual-concentric
Electronics: A rotary potentiometer with two concentric shafts, that is designed to allow a single potentiometer to provide two different resistances (such a radio with a knob to control Front and Rear speaker volume).
Potentiometer, Dual-gang
Electronics: A potentiometer that is designed to change two resistances simultaneously, such as in stereo applications.
Potentiometer, Linear (Taper)
Electronics: A potentiometer in which the increase in resistance is directly proportional to the rotational change. Compare to Antilog Taper Potentiometer and Audio Taper Potentiometer.
Potentiometer, Linear (Slide)
Electronics: A potentiometer that has a sliding adjustment. Commonly used in fader controls and mixers.
Potentiometer, Multi-turn
Electronics: A rotary potentiometer in which the actuator can be rotated a multiple of 360 degrees; most commonly associated with trimmer potentiometers.
Potentiometer, Reverse Audio (Taper): see Antilog Taper Potentiometer.
Potentiometer, Rotary
Electronics: A potentiometer with a rotatable shaft or dial.
Potentiometer, Single-gang
Electronics: A potentiometer that is designed to change a single resistance.
Potentiometer, Single-turn
Electronics: A rotary potentiometer in which the actuator can be rotated a maximum of 360 degrees (one turn).
Potentiometer, Taper
Electronics: Originally, "taper" referred to the actual taper in the construction of the resistance element in audio (or log) potentiometers and antilog potentiometers. It has been extended to describe any potentiometer with a smooth gradient of resistance, including linear potentiometers, even though linear potentiometers do not have a tapered element. See Antilog (Taper) Potentiometer, Audio (Taper) Potentiometer and Linear (Taper) Potentiometer.
Potentiometer, Trimmer
Electronics: A potentiometer that is designed to be set and then left alone for normal operation. It is commonly used for calibrating instruments, and other areas where it is necessary to tune a circuit to provide an exact gain, output voltage, or current. Trimmer potentiometers (or trimpots) do not have a shaft and must be adjusted using a screwdriver or other tool.
Potentiometer, Wirewound
Electronics: A potentiometer in which the resistance element is wire wound on an insulated mandrel. Change in resistance occurs in discrete steps (rather than a smooth transition) as the contact moves from one wire to another, normally used for high-power and/or long-life applications.
Acronym: Plain Old Telephone System
Telephony: A standard, single-line basic telephone system.
Pounds per Square Inch see PSI.
Electronics, Measurement: The unit of measurement of the energy (measured in watts) converted by a circuit or component in a unit of time, normally seconds.
Power Supply
DIY, Electronics: A device designed to accept power having one set of electrical characteristics (voltage, AC/DC, etc.) and output power having different electrical characteristics, such as a power supply that accepts 120 volts AC and outputs 12 volts DC.
Power Supply, Regulated
Electronics: A power supply that maintains a constant output voltage under changing load conditions.
Power Supply, Unregulated
Electronics: A power supply in which the output voltage may vary depending on the load condition.
Acronym: Pixels Per Inch
Digital Video, Measurement: A unit of measurement used to describe the resolution of a printed image in terms of the number of pixels in a given area. The higher the number, the more detailed the image will be.
Video: The color difference between the red component and the luma in the Y'Pb'Pr color space. Also called R' - Y, and often abbreviated to Pr (without the apostrophe).
Audio: An electronic device used to boost weak audio signals before they are fed into an amplifier.
Weather: Any and all forms of water, liquid or solid, that falls from clouds and reaches the ground. This includes drizzle, freezing drizzle, freezing rain, hail, ice crystals, ice pellets, rain, snow, snow pellets, and snow grains.
Precipitation, Freezing
Weather: Precipitation that is liquid, but freezes upon impact with a solid surface, such as the ground or other exposed surfaces. Includes freezing drizzle and freezing rain
Precipitation, Frozen
Weather: Precipitation that reaches the ground in a frozen state. Examples include hail, ice crystals, ice pellets, snow, snow pellets, and snow grains.
Weather: The force per unit area exerted by the weight of the atmosphere above a point on or above the earth's surface. Pressure in weather generally refers to either atmospheric pressure or barometric pressure.
Pressure, Actual
Weather: The atmospheric pressure at the level of the barometer.
Pressure Altimeter: see Altimeter, Pressure.
Pressure Altitude
Weather: The altitude in standard atmosphere at which a given pressure will be observed. It is the indicated altitude of a pressure altimeter at an altitude setting of 29.92 inches of mercury, and is therefore the indicated altitude above the 29.92 constant pressure surface.
Pressure, Atmospheric
Weather: the pressure exerted by the atmosphere at a given point. It can be expressed in millibars or in inches or millimeters of mercury (hg).
Pressure, Barometric
Weather: The pressure exerted by the atmosphere at a given point. It can be expressed in millibars or in inches or millimeters of mercury (hg).
Pressure Characteristic
Weather: the pattern of the pressure change during the specified period of time, usually the three hour period preceding an observation. This is recorded as one of the following three categories: falling, rising, or steady.
Pressure, Standard Surface
Weather: The measurement of one atmosphere of pressure under standard conditions. It is equivalent to 1,013.25 millibars, 29.92 inches of mercury, 760 millimeters of mercury, 14.7 pounds per square inch, or 1.033 grams per square centimeter.
Prevailing Wind: Wind, Prevailing.
Preview Screen
Digital Video: A small LCD display screen on the back of the camera used to compose a shot or look at stored photographs. Also called Electronic Viewfinder.
Pressure Zone Microphone™: see PZM.
Batteries: A non-rechargeable battery designed to deliver the rated capacity once, then be discarded.
Electronics: The first winding of a transformer, that is the input winding connected to the source. Compare to Secondary, that is the output winding connected to a load.
Priority Channel
Communications: A channel on a scanner that is checked regularly during normal scanning.
Private Branch Exchange: see PBX.
Probe, Multimeter
DIY: The part of a multimeter that is used to make directly contact with the circuit or electrical field. Multimeter probes may be either built into the multimeter (as with lower-cost meters) or be separate items, that can be changed out depending on the need. Also called a Test Probe, a Test Lead and a Multimeter Lead.
Progressive Scan:
Digital Video: An image sensor that gathers its data and processes each scan line one after another in sequence. Compare to Interlaced.
Digital Video: Programmable Read Only Memory
Electronics: An integrated chip (IC) that can be programmed with information.
Computer, Electronics: 1) A technology, product or software that is owned exclusively by a single company that restricts technical information on the technology, the product or the software's source code.
2) A technology, product or software that will only function with other technologies, products or software owned by the same company.
Communications: The action of a radio wave to travel through a material (such as the atmosphere).
Computers: A standard for connecting and communicating between devices.
Internet: A standard for transporting data and files. Because protocols are standardized, files being sent can be interpreted by the receiving machine. See FTP.
Weather: Pounds per Square Inch
Weather: A unit for measuring pressure. One PSI equals the pressure resulting from a force of one pound force acting over an area of one square inch.
Acronym: Public Switched Telephone Network
Telephony: The standard wired telecommunications network.
Weather: An instrument used to measure water vapor content of the atmosphere. It consists of two thermometers, a wet bulb and dry bulb. May also be referred to as a sling psychrometer.
p-type Semiconductor, p-type Semiconductor Material: see Semiconductor, p-type.
Public Switched Telephone Network: see PSTN.
Pulse Code Modulation: see PCM.
Pulse Induction: see PI.
Acronym: PolyVinyl Chloride
Cables, DIY, Electronics: A material commonly used in enclosures and as an insulator for cables. PVC cables should not be run in a plenum, as when it is burned it gives off a toxic gas that the plenum would distribute throughout the building.
Acronym: Pressure Zone Microphone (A trademark of Crown International)
Audio: An omnidirectional microphone mounted on a large flat surface in order to take advantage of the natural increase of levels at a surface.

About RadioShack Corporation | Contact Us | Privacy Policy | Store Locator

Copyright© RadioShack Corporation 2004. All rights reserved.