Radio today (Sept 1935-Dec 1936)

SERVICE NOTES (From page 52) striking the diaphragm, cause it to move, thereby changing the capacity. The two electrodes and diaphragm and the stationary electrode are maintained at a potential of 90 volts or more from each other. Advantages : Frequency response is considerably improved over the carbon microphone and also has an inherent low noise level. Limitations : Low output which requires polarized potential for its operation and it is difficult to keep in operating condition due to the extremely small clearance between the diaphragm and the back plate. It is not used very extensively today. Dynamic mike The dynamic type of microphone is a complete self-contained unit that does not require field excitation. It consists of an extremely light voice coil, mounted on a diaphragm. The voice coil is maintained in an intense magnetic field which is supplied by a permanent magnet. Advantages: the dynamic microphone has a low impedance and its noise level is extremely low. It can be made with excellent frequency response. Limitations : It is heavy and must be handled with extreme care. It is essentially an extremely high impedance device and therefore is not applicable for long microphone runs. Also, it is an un-directional microphone. THIRD HAND * For the man who is having a struggle getting dial cables put back on after servicing a receiver, a third (To next page) . SUPERIOR WIRE WOUND REPLACEMENT RESISTOR «*£ PIN THIS AD LETTERHEAD AND MAIL FOR COMPLETE JOBBERS, DEALERS — look into the profit opportunities in this new, different and superior replacement resistor. It's flat, taking less room, permanently accurate within 5%, noiseless, with a nonporous, high temperature, waterproof cement coatingand adjustable leads. Zipohms are made in all standard values, each clearly marked. Write for information on Special Introductory Kit offer today! THE MUTER COMPANY 1255 SOUTH MICHIGAN AVE. CHICAGO, ILLINOIS A NEW POLICY fact&rvpAiceA TRIUMPH'S DIRECT SALES PLAN WW ,„«»>" ...art" ** Profit today through Triumph's new low factory -direct prices. SAVE middleman's profits. SAVE high interest rates. SAVE collection costs of long-time payment plans. SAVE Inventory losses on obsolete radio tube stocks. Buy direct from Triumph. Under the new plan, you are guaranteed Triumph's careful precision manufacturing. Get Triumph's top quality. Pay only Triumph's low prices. You be the judge. Every instrument sold under the Triumph factory-direct plan carries an unqualified money back guarantee. Modernize your tenting equipment NOW. Share in the profits. Be modern! Buy modern! Earn more money. ACT NOW and SAVE. Hear it See it THE VISOGRAPH ... vc e« <*• ■■* T, *.***' jtA-4" New sensational radio tube merchandise!1 . Tiiumph announces a new ideal radio tube BUper-salesman — the Visograph. You see the light — hear the sound. Tests and sells every receiver tube built. Glass, metaglass, and metal. Reversible indicator panel. Ideal counter size. Big, direct, easyreading scale. Attractive illuminated multi-colored test indicator panel. Direct reading speed roll test chart. Beautiful wrinkle finish. Stay modern with the Viaograph. Only S29.94 F.O.B. Chicago. Sent you immediately on order. Only 25% down, balance C.O.D. SMASH GO PRICES See how Triumph's factory -direct policy eaves money — IS to 3f % MODEL wt. Lb,. PRICE 180 Wobbulator 19 $ 46.00 800 Oscillograph .... 33 63.60 Combination Models 180 and 800 52 100.00 120 Signal Generator 300 IVlultirange Volt 15 23.95 5 16 15.95 23.95 420 L Tube Tester . . Portable Signal Generator, Multirange Volt Meter, and Tube Tester 41 65.55 150 Battery Gen 19 23.95 310 Volt-Ohmmeter . 3 7.85 CondenserBridge* Analyzer and 18 14.90 New Visograph 28 29.94 Prices F.O.B. C Chicago Money Back Guarantee We stand back of every piece of testing equipment we sell direct. Your money cheerfully refunded on merchandise returned within 10 days In or) gl nal condition. TRIUMPH MANUFACTURING CO. 4017 W. Lake St. Chicago, HI October, 1936 59