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RADIO. APRIL, 1963 26 Vol. 25 No. I TELEVISION and HOBBIES RADIO, TELEVISION HI Fl PDF

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APRIL, 1963 26 RADIO. Vol. 25 No. I RADIO, TELEVISSIIOONN , TELEVISION HI Fl, ELECTRO)NNIICCSS,, and HOBBIES AMATEUR RADIO, POPULAR SCIENCE, HOBBIES. Registered in Austrdlie for transmission by post as a periodical Mm I tr. ; 7 // / / / / rn ■■■ AHAIGAHATID WIRIUSS VAIVI COMPANY PlY. MM HID RADIOXROIM PICTURE TUBES PAGE 2 RADIO, TELEVISION & HOBBIES APRIL, 1963 o m <1 — o ... • • In radio communications, knowledge is progress. Only knowledge can mean progress; in turn, progress itself maintains our present high standard of living. u r- Radio-communications has its place in the community and the r I»» expansion of this industry with the ever changing techniques require specially trained personnel to keep the picture of progress moving. No one is in a better position to advance with this progress than the B trained technician. The Marconi School of Wireless has combined training facilities MUM with the most up-to-date methods to ensure that every graduate has the knowledge necessary to become thoroughly competent in this field. MARCONI Please send me without obligation your prospectus. FILL IN AND POST NAME COUPON TO-DAY TO ADDRESS OF MARCONI Call, write or phono— MARCONI SCHOOL OF WIRELESS SYDNEY 47 York Street 2 0233 SCHOOL OF Conducted by: MELBOURNE AMALGAMATED WIRELESS (AUSTRALASIA) LIMITED 167 Queen Street 67 9161 WIRELESS {Incorporated in New South Wales) AUSTRALIA'S NATIONAL ELECTRONICS JOURNAL RADIO, TELEVISION and HOBBIES ABC CERTIFIED CIRCULATION IN EXCESS OF 39,000 Volume 135, Number 1. April, 1963 Editors LETS BE REALISTIC! NEVILLE WILLIAMS M.I.R.E. (Auit.) (VK2XV). rpHE results achieved with the "Telstar" and * "Relay" communication satellites have in- Technical Editor: spired a lot of extravagant speculation as to PHILIP WATSON (VKUPW) what it all signities for the future. A.M.I.R.I. (Aust.). For example, our children are pictured, sev- Technical Staff: eral years hence, telephoning their friends over- KEITH JEFFCOAT (VKSBK) seas, as casually as they do now from one sub- JAMIESON ROWE urb to the next. Or better still, chatting half-way IAN POGSON (VK2AZN) across the world per medium of a tiny all- JOHN DAVIDSON (VK2ZJi) purpose transceiver strapped to their wrist. MERVYN HUDDLESTON What possible merit such "forecasts" can Advertising: have I fail to see. No great talent is required SELWYN SAYERS, Mgr. to paint vivid word pictures of the future; science BILL SUMMONS, Rep. Sydney. fiction writers have been doing it for a long DON HARPER, Rep. Melbourne. time and on a vast scale with the added burden of having to supply a plot as well! Circulation: But the present crop of forecasters, having lightly brushed aside W. CUMMINO, Mgr. enormous technical and physical difficulties, equally omit to waste any Subscription Rates: of their talents on such a small matter as economics. The C'waelth, Fl|l, N. Guinea, British Government, for example, is currently considering the •possibility of setting up a Commonwealth-wide satellite communication United Kingdom and N. 'iWi X. British Dominions £A2 p.a. system. Costs have been mentioned of £stgl00 million for 12 satellite Foreign £A2/10/- p.a. repeaters, another £100 million for the launchers, and a further enormous outlay for steerable antennas, transmitters, receivers and terminal equipment. Editorial Offices: 12th Floor, 235-243 Jones St. Can you really envisage all this being turned over to casual, four- Broadway, Sydney. Phone B0944. Ext. 2531, 2525-6-7. penny telephone calls? Or used as an ancillary to some sort of inter- national "Citizens Band"? One would need to be very naive, indeed, Advertising Offices; to believe so. (th Floor, 235-243 Jones St., Broadway, Sydney. Phono B0944, There has been a lot of talk also about satellites being used — or Ext. 2931, 2508, 2510. misused — by one country to flood another with undesired TV pro- paganda. In fact, of course, the historic transmission of television by Circulation Dept.: "Telstar" required the full cooperation of the receiving countries! involving 9th Floor, 235-243 Jones St. Broadway, Sydney. Phone B0944, special aerials and special receivers to pick up the t-iny signal coming Ext. 2505, 2509. from space. After that, the signal lhad to be converted to the local standard and piped to normal TV stations for local transmission. Postal Address; Box 2728, G.P.O., Sydney. (Re To pour illicit transmissions directly into a nation's television re- technkal queries, see "Answers To Correspondents" page.) ceivers, on channels already occupied, would call for an order of trans- mitted power, completely beyond the present concept of satellites, satellite Melbourne Office; equipment and satellite launchers. 392 Little Collins St. Phono 67-8131. Please, gentlemen, let's get down to earth! Cover Picture: ^4/ In this rather unusual group, the geometric shapes are actually "free space absorb- ers" manufactured in the U.S. by Emerson & Camming Inc. and represented locally by Wm. J. MtLellan & Co. Pty. C O N T E N T S Lid. Exhibiting high absorption Pago Page and low reflection to RE Toward Limitless Energy 4 TV Test Patterns 56 energy from about SOMc. Viewing Atoms ... 7 24W. Transistor Amplifier 64 upwards, the materials arc Horizontal Linearity 72 used to line radio frequency Putting The Laser To Work 9 A Reader Built It 74 "anecholc chambers" in which Pay Television . II Lot's Buy An Argument 77 free space RE conditions can Computers Remember 12 Audio Topics 84 be simulated. Solar Powered Satellite 14 Classical Reviews . . 88 Review—Sunflower Optics 17 Variety Fair 93 Interstate Distributors: Review—LF & VLF Standards 21 Trade Reviews, Releases 105 Distributed In N.S.W, by Sungrevure Pty. Ltd., 21-29 Morley Avenue. Rosebery, Scientific, Industrial News 23 Amateur Band News 109 N.S.W.; In Victoria by Sungrevure Ply. Control Unit 104 28 On Shortwave 117 Ltd 392 Little Collins Sl„ Melbourne; The Serviceman Who Tells 35 Answers To Correspondents 121 in South Australia by Sungrevure Ply. Ltd., 104 Currle St., Adelaide; In Western The Answer Man Explains 41 Technical Book Review 125 Austretle by Western Press; In pueens- An Automotive Voltmeter _. 45 Buy, Sell or Exchange 128 lend by Gordon end Gotch 3-Band A-M Transmitter 49 Index To Advertisers 128 (A/eiial Ltd.; In New Zealand by Truth (N.Z.) Ltd.; In Tas- menle by Davlas Bros. Pty. « Radio, Television & Hobbies, April, 1963 Ltd.; "Mercunr." Hobert. ' I f ■ |t?- • •'I ••• tie-*- .■ si mM NOTE. Record storage on the left for 8" recordings and topes, and on the right for 12" recordings. The equipment shelf is 51" x 17|" large enough for the largest imported amplifiers Model 500, like all other Instrol cabinets is available both fully and players. stained and polished in your choice of timber finish, and, be- If required a well may be lieve it or not, it is also available as a complete kit to build specially constructed to suit yourself. your own tape recorder. Smooth Shepherd castors, Moulding mitred, alao Panela are machine piano hinges, beautiful mould- groover for metal strip mortined for smooth. ings and veneers. MAKE YOUR OWN HI-FI CABINETS & SAVE £££'$ So easy a child could manage it. The Instrol way — a new simplified method of assembly. A hammer, screwdriver, one evening of your time, and you can make your own cabinets for less than half cost. Kits are absolutely complete, with easy to follow instruc- tions, nails, screws, grille cloth, felt, moulding, gold trim, legs, castors, stays, etc. All parts are precision cut, fit together smoothly. External panels are from heavy laminated timber with beautifully selected veneer finish. Most Instrol cabinet kits may be posted to any part of Australia. Send now for illustrated price | Selected veneers on list. Beautiful arcoustic top, bottom, and sides. ?grille material. Lining ell also * supplied INSTROL HIGH QUALITY- HI-FI CABINET KITS liii mmpemnt0 rc>a.bhi!nnAet.m vNo,o., ei2r0n0lft,8 es poefa.kcerar fte;,nmcl,aons ucreasb in8eitns aanndd eIn0cinlo/1su2rmes,. tFheronm E qleufitp mtoe nrti gchat biwneet hNavoe. E10q0u,i p- POST COUPON 2 Radio, Te/eWsion & Hobbies, April, 1963 INSTKOI.-I'I.AVMASTER I !NIT PLAYMASTER N... t STEREO AMPUEIEK The aU transistorised Kit of Farts I.iS-14/- Playmaster hi-fi am- Built & Tested £49/1H plifier Kit and built i EQUIFNENT price details now available. OITcrs you a wide range of high quality audio equipment to the original "R. T. V. and H." de- signs. Australian designed, Australian made, guaranteed and lifetime serviced. Available ready built and tested, or in kit form ready to bujld yourself. At a price well below that of similar imported amplifiers. 1NSTROL-PLAYM ASTER PROGRAM SOURCE No. 2 TUNER Kit of Parts £17/13/. Built and Tested H rite, /ihom- or tull for frrc ratiilofmr. £27/3/. INSTROL PLAYMASTER METALWORK AND LABELS FOR ALL GUITAR AMPLIFIER The new "R.TV & H." Guitar Amplifier "R. TV & H" DESIGNS models 102 and 103, now available as a complete kit of parts or ready built and INSTROL — not just a chassis, but really high class metal- tested. The kit is complete in every detail, work. We take all Playmaster, and other popular "R.TV including beautifully finished carrying case &. H." designs, and have the necessary boxes, chassis, panels and your choice of speakers. Full price and labels made to the most rigid specifications. Our price details, etc., in Instrol Playmaster hi-fi list details not only the ran^e of our own Instrol metal- catalogue. All parts also available work, but also the full range of Oxford chassis boxes, labels, separately. etc. Between Instrol and Oxford, we can supply metalwork Cadmium plated and passivated and labels for almost every "R.TV & H." design, Test chassis £ 2 15 10 equipment, TV, Hi-Fi, Instruments, Radio. P.A. amplifiers — all are included. Send now for free INSTROL-OXFORD Anodised Labell Black/Gold, £ I 7 6 metalwork price catalogue. Carrying case with choice of baffle (3 or 2 speakers) .. .. £10 4 0 V in first /imTMiufr jiumhi-<l unit itn/It'll. Then heavy vnilimum /tlafeif In Hu.y anil fnml fHinrl. Sirenm- it as 60 waswametotpsua)llsi,d f iecrd oemt(shocpvrleieebytree- . pfpinroesnMvile invtu< fvnenntmltr /rtuanmir 'ph/iioriinne«gv/ vo.e ,an tt/ h fei'nnnixgaue/lrryr . lalwiannlimedthd n *. umhH ilaaMehra tve tydtIr anemnuhavlaemrimrver lmd un r euvrlllrdlnniinnnligeg with 2 speakers, reverbera- finish for duruhihty. lion, vibrato, in carrying case for only:-— Kit of parts £88/14/8 or Built and tested £100/14 8 Please send details of the □ Instrol-Playmaster HI-FI. following. □ A.K..G. Headphones. □ Instrol Cabinet Kits. NAME □ "R.TV & H." T V Kit. ADDRESS □ Tester K'ts- □ Instrol Metalwork. (Place X in square) BROADWAY ELECTRONICS PTY. LTD. A. B A K B UILDING, CNR. BROAD WA Y & CITY ROAD, SYDNEY. (O P P. GRACE B R O S.) PHONE: BA4891, BA4892, BA4893. Radio, Te/evision & Hobbies, April, 1963 such force that they fuse to form nuclei of greater mass. In each case, the mass of the new nucleus is some- what less than the combined masses of those which fused to form it. The leftover mass is radiated in the form of energy. The fuel for the process is heavy hydrogen, an atomic variant of normal hydrogen, which is found in virtually Jt unlimited quantity in all of the oceans of the world. But while the fuel is plentiful, the means for employing it are so far non-existent. Creating the environment for con- trolled fusion is an immensely compli- cated task which science has yet to prove possible of achievement. The -V. incentives are so great, however, that hundreds of millions of dollars are being invested in fusion research pro- grams that occupy an imposing array The model C Stellarator installed at the Princeton University, NJ. A CLUSTER of large, angular buildings, placed like of scientific talents in the United States and other leading -'*• oversized boxes in the wooded landscape of central nations, including Russia. New Jersey, is the focal point of a major scientific thrust The formidable nature of the problem is evident in that could lead one day to all but inexhaustible sources the conditions that must be created in order to generate of energy for mankind. and sustain the fusion process. The required environ- ment is a vacuum vessel containing a heated plasma — Housed within the building complex is an oval- a gas so hot that all of its electrons are torn away from shaped 180-ton assembly of stainless steel tubing and its atomic nuclei to form what science now recognises immense magnets forming a unique research machine as a fourth state of matter that differs basically from known as the Model C Stellarator—a "stellar genera- liquid, solid, or gaseous states. tor" designed to raise ionized hydrogen gas to tempera- The plasma must then be heated to tens of millions tures approaching those that exist inside the sun and of degrees in order to impart sufficient energy to cause other stars. high-velocity collisions among the nuclei. At the same The C Stellarator and the massive electronic and time, the superheated plasma must be contained in a electric power systems that surround and feed it, repre- limited space for a long enough time to permit an appre- sent an outstanding achievement in university-industry ciable portion of the nuclei to fuse together. government co-operation to forge what is probably the Containers of solid material are useless for this most powerful single instrument for probing a vastly purpose, because the plasma would lose so much heat by challenging frontier of modern science—the quest for contact with the walls that the reaction would be means of achieving controlled thermonuclear fusion for quenched. Instead, scientists are experimenting with the production of power. extremely jtrong magnetic confining fields to compress The Stellarator—designated Model C to indicate the the plasma within the centre of the vacuum vessel, away third and by far the most powerful variant in a series— from the walls. was conceived and is now operated by Princeton Uni- These procedures are based upon well developed versity scientists in a broad research program sponsored theory for which direct proof is so far in short supply. by the U.S. Atomic Energy Commission. The machine For example, it is not yet certain whether the intensely and its extensive supporting facilities were designed and hot plasma can be confined by a magnetic field long built for the University and the A.E.G. by the Radio enough to sustain a fusion reaction. Furthermore, it is Corporation of America and the Allis-Chalmers Manu- equally uncertain whether presently contemplated tech- facturing Company in a five-year engineering team ef- niques can provide high enough temperatures or suf- fort drawing upon new and advanced concepts of elec- ficiently pure heavy hydrogen plasma. tronics and electrical technology. With the great new C Stellarator, the scientists of The mission of the C Stellarator is to explore basic Princeton University Plasma Physics Laboratory hope scientific problem areas in which solutions may open to obtain at least some of the answers to these basic the way to controlled thermonuclear fusion. Success in questions. To this end, the machine is intended to create achieving this long-range goal could tap an energy a laboratory environment in which the problems of source of unbelievable scope, capable of supplying all purity, heating, and magnetic field confinement can be human wants for a billion years to come, at a con- studied at first hand. sumption level perhaps 1,000 times greater than the total The raison d'etre of the powerful instrument is de- of world power requirements today. scribed this way by Dr Lyman Spitzer, jun., originator of Thermonuclear fusion is the energy-producing pro- the Stellarator concept and Chairman of the Executive cess that occurs in the sun and stars. In its simplest Committee of the Princeton Plasma Physics Laboratory: terms, it results from the collision of atomic nuclei with "Smaller devices at Princeton have shown promising Radio, Television & Hobbles, April, 1963 results, but plasma on a small scale cannot be heated suf- ficiently nor confined for a long enough time to carry out research on conditions most relevant to thermonuclear reactor. The Model C Sfellarator, with a diameter four times larger than most of our smaller Stellarators, should produce plasmas more similar to those required in a power-producing device. "Moreover, the auxiliary supporting facilities, includ- ing such systems as direct current generators for produc- ing the confining magnetic field and radio-frequency power sources for heating the plasma, will make pos- r sible an experimental program on a number of large devices of which the present C Stellarator is the first." The electronic aspects of the Stellarator underscore the major role to be played by advanced electronic technology in the quest for — and, hopefully, the eventual use of — controlled thermonuclear fusion. In meeting the unprecedented requirements of vacuum and heat, RCA's development program drew heavily upon long-established skills in electron tube tech- nology, high-power broadcast equipment engineering, and electronic data processing and control systems. Par- o ticipating in the work at various stages of the five-year effort were specialists of the RCA Electron Tube, Elec- tronic Data Processing, and Broadcast and Communi- cations Divisions, as well as scientists of RCA Labora- tories. RCA Laboratories administered the company's portion of the project, and engineers and technicians of .-i f- the RCA Service Company were involved in the in- stallation and testing of the system. LARGE VESSEL Measuring the magnetic field intide a unit of The heart of the Stellarator is an extremely large of the Stellarator't healing system. ultra-high-vacuum vessel — a stainless steel tube eight inches in diameter and 40 feet long, closed on itself to confine the heated plasma for far longer periods than to form an oval resembling a race track. The great had been possible with the earlier small machines used tube is almost entirely hidden within the array of large by the Princeton scientists. magnetic coils which create the strong confining field "The engineering program has been brought to an to hold the healed plasma away from the tube walls. outstandingly successful conclusion with the completion The associated high-speed pumping system can evacu- of the C device, together with the many intricate sub- ate the interior of the tube to a vacuum equivalent to systems and supporting facilities," says Dr Spitzer. "It the near-vacuum of space several hundred miles out from seems clear that the C Stellarator will be an important the earth's surface — about 10 trillion times below the research tool in the controlled fusion program." pressure of the atmosphere at sea level. An array of RCA superpower Rf tubes provides To heat the plasma to the immensely high stellar heal for the model C Stellarator. temperatures needed in experiments, RCA specialists have designed two types of electronic systems. The first is the largest electronic power supply of its type ever installed — an assembly of six to 10 super-power tubes with an output of up to 500,000 watts each. Pulses from the tube assembly generate an extreme- ly strong electrical field around the vacuum chamber, and the plasma inside the tube becomes hot as a result of its electrical resistance. Using this process, the re- searchers can raise the plasma temperature to approxi- mately 1 million degrees. r To carry the heat upward to the temperature levels i of the sun and stars, another type of process has been developed, using large banks of capacitors which store energy for release in bursts of up to 50 million watts. ^Tr- This immense energy is transmitted to the plasma by 1 '-^T. means of coils around one section of the tube. Its absorption by the ions in the plasma should result in further sharp rise in the plasma temperature so the heavy hydrogen nuclei may collide and fuse. 56 To control the operation of the Stellarator, engineers developed an Equipment Action Sequence Timer (EAST), 1 a sophisticated relative of the electronic equipment used in various industrial control applications. The system may "r be thought of in terms of 80 persons with stop watches, all synchronised with one another to a precision of a fraction of a millionth of a second. Twenty-five of the 80 are used for switching on and off the major appa- ratus such as the heating systems. The others provide trigger pulses for the instrumentation used to observe and measure experiments. Already, research with the great machine has start- ed to provide vitally needed information by its ability Radio, Television i Hobbies, April, 1963 (KAtiumaUatiwi WITH TAUT BAND SUSPENSION The Pa+on Range of Heavy and Light Duty Volt and Ammeters is now available at an OPTIONAL ALTERNATIVE with Revolutionary TAUT BAND SUSPENSION Move- ments. No jewels, no pivots, no springs, no hysteresis, no friction. The complete solution to shock and vibration problems. Extreme sensitivity from 10 micro- ■W amps F.S.D. — The ultimate of Consistent Reliability. Illustrating THREE VERSIONS OF MODEL 536 uare Pattern). 20 30 kV ^ » © © STANDARD QUADRANT CONCENTRIC 5" Scale 6" Scale 9" Scale PATON ELECTRICAL MAKE THE COMPLETE RANGE —OVER 40 CASE SIZES. From 2" to 10". In Square, Round (Flush or Projection), Edgewise, Sector, etc. Moving Iron, NOW The PATON Moving Coil, Dynamometer and Thermal—Synchroscopes, Frequency (Reed and Dyna], Watts, Power Factor, etc. Clip-on Multi-Range MULTIMETERS Series 32 (32 Ranges) AMMETER i Model M32, 1,000 Ohms/V, Pivoted Movement £14 17 6 „ Taut Band .... £16 7 6 with TAUT BAND | Model MX32, 20,000 Ohms/V, Pivoted Movement £23 10 0 SUSPENSION iq Taut Band .... £25 0 0 Model MXL32, 40.000 Ohms/V, Taut Band, only £29 5 0 Ranges: 0/10, 30. —100./^g OVERLOAD METER PROTECTION fitted to all multimeters. —300, —1,000 amps. Ac. Write for TERMS. PRICES PLUS TAX. Price: £29/10/. M. SERVICE: Paton Instruments are AUSTRALIAN MADE and backed by FACTORY SERVICE. PRICE LIST and CATALOGUE available from: PATON ELECTRICAL PTY. LTD. Established over 25 years Specialists in Meters and Rotary Switches Wm' ASHFIELD, SYDNEY—71.0381 (6 lines) REPRESENTATIVES IN ALL STATES Radio, Television & Hobbles, April, 7963 VIEWING ATOMS with a Field Ion { Microscope The world's most powerful microscopic device, developed recently by a well-known U.S. physicist, is destined to open new areas of scientific research and knowledge, especially in the field of metallurgy, according to scientific experts. THE super-powered "Muller Field Ion Microscope," developed by Dr If Erwin Muller (Pennsylvania State Uni- •versity), is capable of producing clear, precise magnifications in excess of two (Right): Itched to million diameters. Using the microscope, such a fine point {V scientists have been able to see indi- that it mutt be vidual atoms for the first time. examined initially ' Although the existence of the "atomic under a stereo- Lattice," composed of atoms measuring microscope, a me- only about 12 billionths of an inch in tallie specimen is tlil ' diameter, has been known for about 50 here being pre- V|||p|l years, it remained unseen by the eyes of pared lor exami- "jL science until the perfection of this new nation through the microscope. Muller field Ion First commercial models of the instru- microscope, ment were introduced by the Central Z' >' effect causes great magnifications on the screen, which illuminates — like a tele- vision screen—wherever the ions strike. The result is an exact image on the screen of the surface of the metal speci- men, magnified up to two million times. A mirror and attached camera enable the experimenter to photograph the mag- (Left). A nearly nification. perfect crystal of tungsten it por- Already the Field Ion Microscope has trayed in thil helped solve serious problems relating photo micrograph to the performance of metals under con- taken, with the ditions in outer space. Defects in the new field Ion atomic structure of the silver-white microscope. Mag. metal molybdenum, exposed to radiation nified 2,700,000 in space, could be seen with the ion times, each lumin. microscope when not visible under the most powerful electron microscopes ous spot repre- (which tend to blur in magnifications sents an individ- approaching one million diameters). The ual atom of mat- defect proved to be a missing atom in ter. the crystalline "atomic Lattice" of the metal. Scientific Company division of the Cenco Because of the principles upon which Scientists hasten to point out. however, Instruments Corporation at a recent the Cenco microscope operates, it is that the Field Ion Microscope, despite Chicago microscopy symposium. at present limited to use only on metals its superior power, is not a replacement According to A. T. Sheldrick, direc- possessing higher ionization potentials for electron microscopes. Price of the tor of Watson-Cenco Pty. Ltd. (Marrick- than helium and other rare gases used new microscope is about' one-tenth that ville, N.S.W.), Cenco's Australian in the magnification process. These of the average electron microscope. affiliate, the new microscope is expected metals include tungsten, platinum, Speaking at the microscopy sym- to bring dramatic new research dis- iridium and molybdenum. posium in Chicago. Dr Muller expressed cfioevldesr,i esa, nd esppreocvieal lyu sefiunl ams etaa llsucrigeinccael coTnvheen tiinosntarlu mteelnevt isoiopne ratutebse manudc hc olinkseis tas hscoipeen titshtsa t atrhoeu ndde vtihcee , wfuorrtlhd,e r mriegfihnte ds oobny eadnduC coaultnuioimvneb risatio tioelUs . niniv etrhsiet y wo(rNlde'ws coYlloergke)s, ogflefu noa.r easD cveewancta usru cmrvee espns,eu lma hpmoinledgtai nld gec volinicqeeu , iidna wnwihhtiricothe- twbieso suuulesd.e da foSfneuc ctbh i obalio ogldoiecgvayel lommpaumtctehenr t,aa sn hdet h hesu tamftiearssn,t user of one of the first commercially the specimen is enclosed, a camera, and Sputnik revolutionised the field of space produced field ion microscopes, plans to a 25,000-volt power supply. research. employ the instrument to investigate the atomic structure of metals, the atomic Helium is inserted into the apparatus Muller's hopes for major scientific at five microns of pressure. With high breakthroughs as a result of world-wide nature of defects in the crystalline struc- ture of metals and alloys, the interaction voltage applied, a field is created around distribution of the Field Ion Microscope between alloying atoms and these de- protruding atoms on the surface of the are not unfounded. fects, and for the study of various sur- metal specimen. This causes the helium Now, well into the second decade of face atomic reactions. in contact with the surface of the speci- the "Atomic Age," with the development Immediate applications of planned re- men to ionize. The field then "shoots" and world-wide commercial availability search employing the new microscope the helium ions toward the fluorescent of Cenco's Muller Field Ion Microscope, include improvements in the strength screen. TTie ions fan out, striking the man—it seems—has only begun to dis- and resistance of metals and alloys to screen in the same pattern they occupied cover and explore the secrets of the corrosion. on the specimen surface. The fanning atom. Radio, Televition & Hobbles, April, 1963 f/u\ LOUDSPEAKERS The Rola engineered 8" x 4" elliptical loudspeaker series, a new design concept now available for the first time in Australia permits substantial savings in cabinet space yet sacrifices nothing in the acoustic efficiency or reproduction qualities expected of larger types. These Rola 8" x 4" models set a new performance standard for the space- saving elliptical type loudspeakers required in modern "Slimline" TV and Radio receivers and will have^a ready application in current and future de- signs of Television, Stereo and Mantle and Auto Radio receivers. Three models — 8-4C, 8-4H, and 8-41 — are available to meet the various power handling requirements and acoustic efficiencies called for in TV and Radio receiver design. Apart from this, as will be seen from the brief specifications listed below, all of the 8" x 4" loudspeakers are identical, except for a reduction of the front-to-back depth in the case of Models 8-4H and 8-4C. PRINCIPAL. SPECIFICATIONS Model 8-4 C 'Model 8-4 H Model 8-4 L Power handling capacity 3/3 Watts Peak 6 Wans Peak 7 Watts Peak Voice coil Impedance All Models. 3.5 or 15 ohms at 400 c.p.s. Frequency response All Models. 105 c.p.s. — T k.c. Air gap flux density 7,250 Gausses 9.200 Gausses 10,200 Gausses Gap flux 16.200 lines 22.800 lines 25,300 lines Principal dimensions; Overall diameter of diaphragm housing All Wlodcls. 8)m" x 4)6" Diameter of baffle opening 7V x 3V TV x 3 V 7V x 3 V Diameter of voice coil %" %" Va" Depth from pad ring to rear 21/4" 2'/j" 2%"

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In radio communications, knowledge is progress. madulated systems, relavs and escapements, and no know,edge of what margin of.
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