Radio Broadcast (May 1929-Apr 1930)

RADIO BROADCAST ADVERTISER. Picking Out Imperfect Tubes is easy with our Type 443 Mutual Conductance Meter. This readily made measurement shows up incorrect spacing of the elements as well as faulty filament emission. Demand this test of the tubes you buy and make it on the tubes you sell. Bulletin UU3-T Describes It GENERAL RADIO COMPANY 30 State Street Cambridge, Massachusetts 274 Brannan Street San Francisco, California Universal Resistance! BY means of the adjustable micrometric resistance obtained with the Clarostat, the radio service man can instantly obtain the precise resistance for best results in any radio circuit. Clarostat means universal resistance— hand-fitted to the requirements. The Clarostat line includes a wide range of variable resistors, ranging from tiny Grid Leak and Volume Control types, to giant Power and Super-Power types for high-power amplifiers and auditorium installations. Also includes the Hum-Dinger — a perfected hum balancer for A-C tube circuits, and complete assortment of improved wire wound strip resistors. There is even a refined socket antenna plug in the Clarostat line, which will generally equal a good antenna in performance— just the thing for temporary receiver installations, or as a tonic for poor reception. In short the Clarostat line is to the radio service man what the first aid kit is to the doctor. Be prepared for all emergencies: include Clarostats in your repair kit! Write for literature *ftf*jj£ plete line of Clarostats and how the various types are applied to service problems. And if you have any special resistance problems, do not hesitate to call upon our engineering staff for cooperation. CLAROSTAT MFG. CO., Inc. Mem. H.M.K. Specialists in Rait io Aids — 55 284-7 N. 6th St. Brooklyn. N. Y. Whatever • •• ilttihiitiy from a Crystal Set . . to the 1 7 tube "Hoofus-Doofus" it'll be that much better for using Polymet Products and that goes for the man who builds one set for his family or the manufacturer who turns out thousands every day. It all comes down to this— "You can't make a silk purse out of a sow's ear". In the same way, a good radio, to be and to continue to be a good radio, must start with good parts; c. g.— Polymet Products. We know that you'll find them wellmade, uniform, carefully tested, accurately rated and thoroughly dependable, because that's the only way they leave our plants. Filter Blocks, By-Pass Condensers . . . Bakelite Mica Condensers . . . Resistances POLYMET MANUFACTURING CORPORATION 837 E, 134th St. New York City •'Visit our booth1' No. 7G, at the K. M. A. Show." PO¥,YI?IET PRODUCTS The Shielded Filtered Short Wave Converter Factory-Built, Ready to Plug Into Any Present Radio Set The Aero 192 9 Converter is a compact factory-built short-wave adapter equipped with special short-wave coils. It is designed for both A.C. and D.C. sets. Operates on A.C. or D.C. sets without motorboating, by an auxiliary filter system control, an exclusive feature (patent applied for. ) It can be plugged into any regular radio set. This amazing radio instrument now makes it possible for you to reach 'round the world. (Geo. Morcroft of Pa. received England, Australia and Holland on his initial test.) Permits you to enjoy international programs and many others from coast to coast that your regular receiver cannot get. What a thrill it is to plug this into a tube socket on your regular set and instantly be in another world! No change or wiring required. All complete, ready to operate, tubes and coils hidden, no apparatus in sight, except the neat, golden-brown, compact metal cabinet in crackle finish. Size, 9 x 5 V4 s !K in. Cushioned feet. The only converter we know of that really works on all sets. Two models — A.C. and D.C. Write for Catalog and literature, or send 52 5.00 less 40% and name of your jobber. New Aero Supplement now ready. Ask for it. Model A, without tube, for A.C. sets List Model D, without tube, for D.C. sets List, INICOR PORATED 4611 E. Ravenswood Ave. Dept. 269 CHICAGO, ILL. Ideal Condenser for Equalizing For balancing the sections of a multiple condenser — for neutralizing oscillations in radio-frequency amplifiers — for antenna coupling to improve selectivity. Ruggedly built with Bakelite base mount, mica dielectric and phosphor bronze spring plate, safe — cannot short. Compac t — fits in small spaces. Lug for direct attachment. Two sizes: — 35 ninifd. and 70 mmfd. Write Dept. R B 6 for descriptive folderof llainniarhmd Products. HAMMARLTJND MFG. CO. 424-438 W. 33rd St., New York » ammarlund PRECIS t£>N PRODUCTS • june, 1929 page 122 •