Interconnected telephone lines for use by

the general public public telephone exchange /,рлЬНк

'telafoun iks,tjeind3/ [27] switching centre

In a public telephone network which

switches the signals from one line to

another

puff /рлг/ [1, 28] see picofarad (pF)

pulse /рлк/ [ 12] a sudden increase then decrease in voltage or current

pulsed /pAlst/ [8] in the form of a rectangular wave with short duration

push-pull configuration /put pul kanfiga.reifn/ [13] circuit arrangement in which each half of the circuit is 180° out of phase with the other half. It allows the complete cycle of a signal to be used for driving loudspeakers.

PVC /,pi: vi: 'si:/ [26] polyvinyl chloride: plastic insulating material used to protect some cables

_□

R and D /,а:г эп 'di:/ [29] research and development

_{quartz crystal /'kwo:ts .kristal/ [19] naturally occurring silicon oxide crystal which vibrates at a fixed frequency when an AC voltage is applied to it. It is used in oscillators to produce a very stable resonant frequency.}

radar/'reida:(r)/ [8, 26] radio detection and ranging: electronic system which uses the reflection of microwaves to detect the presence of an object and measure its distance and position relative to the transmitter

radiate /'reidieit/ [26] give out rays in all directions

radiation /.reidi'eijn/ [8] electromagnetic

wave sent out in all directions radio (set) /'reidiau (.set)/ [1] device for

receiving radio frequency signals radio frequency/'reidi au .friikwansi/ [10]

frequency between 100kHz and 300GHz radio phone /'reidiau ,faun/ [27]

telephone which transmits and receives

radio frequency signals radio receiver /'reidiau ri,si:va(r)/ see

radio (set)

radio tuner /'reidiau ,tju:na(r)/ [13] part of a radio receiver for selecting the desired radio programme

radiopager /'reidiau ,рек1зэ(г)/ [28] mobile radio communications device which beeps to let the user know that someone is trying to contact them

radiopaging /'reidiau,peid3irj/ [28] communications service using radio pager devices which beep to let the user know that someone is trying to get in contact with them

radiopaging system /.reidiau 'peid3irj .sistom/ see paging system

RAM /гэет/ [23] random-access memory

random access /.rasndam 'askses/ [16, 23] access to any area of a recording without having to go through other recorded areas

random-access memory /'rasndam 'askses .memari/ [23] 1С chips used in computers for the temporary storage of programs and data. Data can be both written to and read from them.

range /remd3/ " 1 [6] selection between an upper and lower limit 2 [10] the maximum distance a wave can travel

ranging /'remd3irj/ n [29] process of calculating how far away an object is

raster pattern /'raesta.pastan/ [20] scan path of an electron beam going across and down the screen of a television receiver

ray/rei/ [19] narrow beam of light

read-only memory /ri:d 'aunli ,тетэп/ [15, 23] 1С chips used in computers for storing fixed programs and data. The user's data can be read from them but not written to them.

realign /ri:a'lain/ [24] go back into line with

receiver /n'si:va(r)/ [8] electronic circuit for receiving signals

reception /n'sepjn/ [21] receiving of transmitted signals

recharge /,ri:'tja:d3/ [5] restore the charge or energy to a battery

record /'reka:d/ n [6, 16] see gramophone record

record /ri'koid/ v [6] make a recording record player /'reko:d ,р1ею(г)/ [1] device

for playing vinyl record recordings recorder /n'ko:d3(r)/ [6] machine use to

record sound or video signals on magnetic

tape

recording /ri'ko:din/ [6] sound or video

signals stored on a disc or tape recording studio /n'kordirj ,stju:di9u/ [14]

place where recordings are made rectifier /'rektifai3(r)/ [5] electronic circuit

for changing AC into DC rectify /'rektifai/ [5] change AC into DC redial /.rii'daial/ [26] memory function on

modern telephones which can be used to

automatically dial a telephone number

again

reed switch /'ri:d switj7 [9] small electrical switch enclosed in a glass tube which operates when a magnet is brought close to it

reel /ri:l/ [21] circular holder for magnetic tape

reel-to-reel machine /riil ts ri:l ms'J'iin/ [21 ] tape recorder which moves the magnetic tape off one reel on to another reel as it passes the heads

reflected wave /n'flektid weiv/ see sky wave

reflection /n'flekfn/ [10] change of

direction of a wave after hitting a surface reflective /n'flektiv/ [24] causing reflection reflector /ri'flekt9(r)/ [10] device that

reflects energy relay /'ri:lei/ n [9] electromechanical switch

operated by an electromagnet relay /n'lei/ v [27] pass on a signal remote control (unit) /ri.maut kan'traul

(ju:nit)/ [8] device for controlling

equipment from a distance reset /,ri:'set/ v [9] restore to starting

condition

resistance /n'zistans/ [5] opposition to the

flow of charge resistivity /.rizis'tiviti/ [24] resistance

property of a material which depends only

on the type of material and not on its size resistor /n'zist3(r)/ [1, 4] electronic

component for opposing the flow of charge resonant circuit /'rezanant ,s3:kit/ see

tuned circuit resonant frequency /'rezanent

.friikwansi/ [10] frequency at which a

tuned circuit will naturally oscillate reverb /'ri:v3:b/ n [6, 7] see reverberation reverberation /ri'vsiba.reij'n/ [6,7]

artificial echo effect produced by

electronically delaying the sound signal reverse bias /n,v3:s 'baias/ [9] DC control