Radio today (Jan-Mar 1939)

SERVICE NOTES tomers with the completeness and modernity of his service equipment and to make it freely available at a number of bench positions in his shop, Moore has installed his major service instruments in a roller-mounted cabinet of eye-arresting design and proportions. The advertising that his customers have given him, as well as time saved through bringing his laboratory to the work as needed, instead of vice versa, has more tban repaid cost of construction. For a complete receiver cheek-up in his service work Moore employs latest time-saving dynamic methods with cathode ray, and so makes certain of turning out a perfect job at pleasing, prices to the customer. At the same time he assures a worthwhile profit for himself. Included in his rolling instrument assembly are a frequency-modulated r-f oscillator, oscillograph, capacity analyzer, vacuum-tube voltmeter, 15-watt amplifier, and a variable dummy antenna. BLIND MAN CHECKS TUBES, FIXES RADIOS BY BRAILLE Cecil Minard of Sandusky, Mich., is a man to remember. As far as we know he is the only radio dealer who tests tubes by Braille. Since 1925, Mr. Minard has serviced and sold sets. Yet he can't see a thing. Tests All Receivi Tubes, Including New 50-Volt Series, Loctal Types and Gaseous Rectifiers. Separate Plate Tests on Diodes and Rectifiers. Neon Short and Leakage Test. Illuminated Dial and RAD-GOOD Scale. • WITH THE 5 TRIPLETT SAFEGUARDS against ObioUicance i THE TRIPLETT ELECTRICAL INSTRUMENT | 192 Harmon Ave., Bluffton, Ohio ■ Please send me more information on □ Model 1615. □ I am also interested CO. in ! City . State complete in carrying case True dynamic mutual conductance tube tester with simplified push-button control, the ultimate for a complete tube test. Amplifier and power tubes checked under operating conditions. Direct GOOD-BAD tube reading on two-color scale. Both filament connections are made through push-button switches, allowing for roaming filaments. Same is true of plate screen, C. G. location switches, etc. Rotating chart has data for more than 200 receiving tubes — plus ballast tubes. Upto-date replacement charts available at any time on a nominal cost exchange basis. *A11 Triplett Testers Selling for Over .•(i^.'.OO Are Available on Attractive Time Payment Plans. See r*our Jobber or Write for Details * PucliUnt' ELECTRICAL INSTRUMENTS For checking tubes he uses a Supreme 506 Push Button Tester with a hinged meter case that permits him to feel where the needle rests. There is also a special jack so he can hear if a tube is leaky or shorted. Also by listening to the hum of the transformer in the tester he can tell whether a tube is good or bad. Instead of the usual roll chart, he uses a special Braille tube card that gives him needed data. Mr. Minard also services radios by listening to their reproduction or by using batteries and an earphone. Thirteen years in radio, he has steadily increased his business despite the terrific handicap of blindness, now owns his store and employs a service man. BOOK REVIEWS THE HISTORY OF RADIO TO 1926 By Gleason L. Archer, LL.D. President of Suffolk University Starting with fire beacons in ancient times the author hurries through important developments in communications to the discovery of radio. He gives the olive wreath to Guglielmo Marconi for discovering practical wireless, but recognizes Henry, Faraday and Maxwell as the scientists who first found electro-magnetic impulses travelling through space. It was Henry Hertz in 1887 who unlocked the wireless secret and proved electric waves could be sent at will. Then Crookes in 1892 prophesied "telegraphy across space" in a magazine article and Edouard Branly in the same year devised a detector. Portable service lab designed and built by Ernest Moore of Chickasha, Okla., saves time, impresses customers. 44 Radio Today