Radio- Electroñic1s F O R M E N W I T H I D E A S I N ELECTRONICS 6ERNSBAGK ELECTRONIC TIEPIECE5 BUILD Multipurpose IC Digital Clock Customize to fit your needs Timer -alarm you set to the minute Stop watch Interval timer 12 or 24 hours ,r.'s o. ocr- -wc -or_ NEW! IC Wristwatch ha s digital readout flW VTR's go portable U Special charger for rechargeable alkaline cells Jack Darr's Service Clinic solves your problems I(ECTIIO 1111011111KET EVERYTHING IN ELETRONICS! TAPE RECORDER MICROPHONE VARIABLE BALANCE STEREO Outstanding performance on music HEAD PHONE and speech for the price. Low im- EXPERIMENTER'S CIRCUIT HOBBYIST'S SOLDERING AND pedance matches late model BOARD KIT Unique "Sound Level" control TOOL KIT solid on state recorders. Removable desk Contains a 33/4" x each earpiece permits adjustment. Diagonals, 4" perforated long nose pliers, solder- stand; 41/2' cord with dual plugs Frequency range: 20 to 20,000 board. 15 terminals (No. 14636) + ing iron and solder. solder aid tool, that fit most models. Freq. Re- and 4 mounting feet w /screws. cps. 61/2' cord with stereo plug. heat -sink, and screwdriver. An ideal sponse: I00 8k Hz. Output: 77 Build small Impedance 4 to 16 ohms. gift item. - circuits, hobby and dB Impedance 200 ohms science projects, etc. Cat. No. Q4-132 $17.95 Net Cat. No. H3.378 $7.95 Net. Cat. No. Q4 -146 $4.95 Net Cat. No. 14 -660 $.98 Net WIN 1 Ye_ MINIATURE LAMPS Type PR2.2.5 volt 0.50 amp Cat. No. E2.430 Pkg. of 2 $.29 Net Type PR3.3.6 volt 0.50 amp Cat. No. E2.431 Pkg. of 2 $.29 Net THE "GC CALECTRO HOBBYIST TWO STATION WIRELESS HANDBOOK" INTERCOM STANDARD 1000 VOLT CAPACITOR The "GC Calectro Hobbyist Hand. Just plug into any electrical outlet. High quality, AUDIO ADAPTORS compact and reliable. book" is available at your nearest Completely portable. Expand sys- Calectro Electronic Supermarket. "Y" Audio Adaptor has a phono pin tem anytime with additional units. RESISTORS jack One is located near you WRITE on one end and dual phono Two unit system complete in dis- Attractively packaged 2 per pack, TODAY and we'll rush you pin plugs on the other. play pack. the name showing values, color codes and and address of your nearest Calec- Cat. No. Q4-288 $.99 Net Cat. No. N4 -110 $34.95 Net form, las. tro Supermarket. G-C ELECTRONICS e) lpg,,,,...," CALECTRO HYOROMETALS, INC. 400 SO. WYMAN ST, ROCKFORD, ILLINOIS 61101 Mr. Technician, You Can Move Ahead by Taking These Grantham School of Engineering NE -6 -70 Three Big Steps 1505 N. Western Ave., Hollywood, Calif. 90027 Gentlemen: to Success... Please mail me your free Bulletin which explains how the Grantham educational program can prepare me for my FCC in license and Associate Degree in Electronics Engineering. I understand no salesman or counselor will call. Name ELECTRONICS Address City State Zip ENGINEERING I have been in electronics for years. L J There they are - three big steps that lead electronics tech- nicians to greater success - three deliberate steps to greater recognition and more income. Your future is shaped by the moves you make - by the steps you take. Begin now with Step #1. 10:411111+:4111163K4MINIRKOIIIERKWtiIAKII STEP *1 is a simple request for full information on the iìaiyctm,tr`.tlrriíi. Grantham Electronics Degree Program. You take this first rEntsfLtt.ewffnr. 'HA-r.10. afnatrftito. coupon. Then, we mail aiMfuativón:stJtittiteNoJlw[oolim step by filling out and mailing the itsfojfo rlw.rirs.. our catalog to you; we do not send a salesman. STEP #2 is passing the examination for your first class FCC license. It is certainly true that an FCC license is important - sometimes essential - but it's not enough! Without fur- ill, ther education, you can't make it to the top. Get your FCC license without fail, but don't stop there. To prepare for the : _ best jobs, continue your electronics education and get your degree. STEP *3 is earning your Associate in Science Degree in j Electronics Engineering (the ASEE). If you have completed .......4e.,a-ä+Er:_s1M:é T-:ß3Z."ts rZi:Lf+,. at least one year of fulltime experience as a bona fide elec- tronics technician, you may earn your ASEE Degree almost entirely by correspondence - including a minimum resident attendance of only two weeks. Accreditation, and G.I. Bill Approval by the Ac- Scijoot of engineering Grantham School of Engineering is accredited @rantfjam crediting Commission of the National Home Study Council, ryas toilful-to on is approved under the G.I. Bill, and is authorized under the laws of the State of California to grant academic degrees. joint pot Home Method thr orgrtc of The -Study 7lggoúatt in eitntt in electronicg tangineeríng Grantham School of Engineering is a specialized, college - level, educational institution - established in 1951 -which !hereunto In mmne.s Wrest INS sp... mnh all Ito rights ..e .rmecae. .awrmmna by the so- called "new approach." This eui. faure ent wen mure Or m, mwi ae.mrr.i,nn uc. n re..mmenruol r rk teaches engineering is the method (often referred to by names such as "inde- WWI? III TIN .b.M km. M/~'.1_i'. ' pendent study ") that has recently created great interest among college educators. Actually, this "new approach" is / .refkN new at all. Grantham and many other good schools have M11/rM-,.,4-1 not been using it for years, under such names as "home study" and "correspondence instruction." As a technician, you already know the "hardware" side of CRANTHAMENGINEERING electronics, and you can upgrade from technician to engi- "the college that comes to you" neer while you continue your employment as a technician. 1505 N. Western Av, Hollywood, CA 90027 Get complete details. Mail the coupon for our free bulletin. Grantham is an Accredited Member of the National Home Study Council. ItCircle 1 on reader service card Circle 2 on reader service card NEW &TIMELY Volume 41 Number 8 RADIO -ELECTRONICS August 1970 AIRBORNE COMPUTER TO GUIDE SHUTTLE JETS DIODES USED IN HIGH -DENSITY IC MEMORY BOSTON LOGAN MURRAY HILL, N. .l.- rogation pulses. Bell predicts The tiny memory cell shown read speed rates to 50 bil- in the scanning- electron -mi- lionths of a second. LA GUARDIA AREA NAV. i WAYPOINT is a new IC A memory capacity of A NAV. croscope photo WAYPOINREA T type under development at 100,000 bits per square inch WHITMAN MADISON Bell Labs for future tele- may be possible, according to -- -____ `` NORWICH phone systems. PROVIDENCE switching Each .003 x .005 -inch cell Area navigation vs. conventional navigation (dashed line) from New York to Boston. Below, the display chart and (left to right) auto- in the IC array is a reverse - pilot controller, distance /time display, computer control and computer. biased Schottky diode con- nected in series with a diffused l á' pn junction diode. A large or small charge (1 or 0) is placed on the reverse- biased diode. ;,. Each bit must be replenished every 1/20 sec as the charge dissipates. The design is called "charge transfer diode memory" since the charge is temporarily transferred to the other diode during read and Bell. The company is looking write operations. Cells are ar- for better memory systems to navi- NEW YORK- Eastern Air- radio stations (or other ranged in an x, y structure handle the information that inputs) and contin- lines' Air -Shuttle jets oper- gation using a metal beam for "x" must be stored for telephone Bos- ually plots the posi- ating into Washington. aircraft's and a silicon bar for "y." calls. Two 10 -digit phone a chart. Pilots ton and New York -area tion on moving Readout is accomplished by numbers (for the called and see hearing to airports this fall will use a can range and detecting the charge stored in calling subscribers) require at computerized navigation sys- points along the route by se- a cell by sensing the foward least temporary storage of tem to fly shorter, less con- lecting the geographical posi- charge flow through the x, y some 80 binary digits. tion on the computer control gested routes. leads in response to inter- (N & T continued on page 6) Pilots will not have to 12 -key turret switch. Each thread their way from one digital key defines preselected navigational radio station to points. The autopilot control the next. Traffic now must unit couples the computer - slow down when aircraft on based navigation signals into the same or intersecting the aircraft's autopilot. routes overfly radio stations. Eastern is buying the sys- The system, called Omni - tem from Decca Navigator trac, uses a 4096 -word, 50- Co.. a British firm. byte digital computer that ac- cepts radio signals from FAA APOLLO 13 OVERLOAD HOUSTON -An overload of voltage applied to two heater switches in an Apollo 13 oxy- gen tank apparently caused the explosion aboard the spacecraft. The overload oc- curred during an attempt to drain the tank prior to the April 11 blastoff. Because of difficulty in draining the tank, 65 volts dc was applied to the thermostat A miniature electromechanical servo system attached to a camera in switches, which were designed a helicopter made the dramatic difference in these photos of the Jeffer- for 30 volts. This apparently son Monument in Washington, D.C. The shots were taken with a 400-mm Las Vegas -Some 300 radio -con- fused the switches, causing lens at 1/50 sec, but helicopter jiggling and vibration was sensed by trolled, scale -model aircraft will heaters to slowly bake away two tiny gyroscopes mounted in a bellow-like collar in front of the be matched in international com- camera lens.