Radio today (Sept 1935-Dec 1936)

SERVICE NOTES If tuning meter does not perform properly or is not sensitive enough, difficulty usually is with the control tube — try a new 6C5 tube before looking for trouble elsewhere. Also check meter for open circuit. VOLUME CONTROL REPLACEMENTS * Reviewing the experiences of thousands of servicemen in handling volume control replacements, George Mucher, Chief Engineer of Clarostat Mfg. Co., offers the following "don'ts" : D'on't attempt to replace C-bias and antenna C-bias controls before checking — 1. Control tubes for "shorts." 2. Bleeder resistor (if used). 3. Whether original control has a built-in bias resistor. In such eases use external bias resistor if exact duplicate control is not available. Don't attempt to replace screen grid control before checking— 1. Control tubes for "shorts." 2. Screen by-pass condensers for "shorts." Don't attempt to replace plate circuit tone controls before checking series condensers for "shorts." Due to high AC voltages generated across control on loud signals, we strongly recommend the use of wire-wound controls for such applications. Failure to heed the foregoing "don'ts" may result in burned-out controls. HEADPHONES ON ANY SET * Addition of headphones to supplement speaker reproduction is comparatively simple and will produce additional profits for the wideawake serviceman. When installing headphone jack or adapters there are a few musts to be followed : high voltage DC must be eliminated from headsets, and some method of disabling the speaker must be employed. High voltage can be eliminated by connecting the headsets in low voltage circuits — such as secondary of a-f. transformers, or by placing condenser (.1 to 1 mfd.) between one terminal of phones and high-voltage and grounding other terminal. Phones can well be placed from plate terminal of audio tube to ground, across secondary of interstage audio transformer, or across secondary of output transformer. (To next page) July. 1936 Tka Wm&U 3*a£ ?)xi£<u> " :JK£®@W§ INTERNATIONAL RADIO CORPORATION. ANN ARBOR, MICHIGAN. U.S.A. NATION POPULAR P. A. SYSTEM on UNION PLAN The Largest Per Cent of Increase This Year in the Radio Business is Being Done in Sound Equipment... National Union believes this field should gravitate to the radio service dealer. Now is the time to get started. National Union makes it easy for you to go into this business by furnishing equipment on National Union deals, '^HUlK Uebster-Chlcago Model PA-41/A requiring minimum outlay of cash. Further, National Union will help you learn the busi A^«™«1«*^ -.«.^*.-.ui« <,^,-.~A ness; how to sell, how to rent, how to expand, complete portable sound how to explore the possibilities, just the psam<: *' CHICAGO/*"-/ svstem having a dual Qia way that they did in helping service dealers V^^SSSj/ phragm crystal micro build up service work. Don't delay— Get into ^^ phone, a 4-stage amplifier sound now! usmg 6 tubes (furnished) a dual input Tfce No,;ona, Unlon w mixing system, ana one D.C dynamic Shaker; all contained in carrying case. Through National Union's help radio service dealers everywhere have been able to set up better equipped shops to do better work; also Other National Union Offers to obtain merchandise helps that produce more customers. National Union has constantly put In SOUND EQUIPMENT items available in tne latest advances in scientific equipment as elude 17-watt portable system, 10-watt portable well as modern selling aids within reach of the system. 6 watt portable system, phonograph service dealer. The National Union deal calls pickup and turntable, etc. for a dealer deposit which is rebated when the In SERVICE EQUIPMENT items available specified number of tubes have been purchased, include tube testers, analyzers, oscillographs, °vf 5°'00° 9°mP «<=d deals Every service signal generators, modulators, meters. Stc. dealer should investigate. In SHOP EQUIPMENT items available in u . e j /» i elude stock cabinets, coats, display signs, etc. Act Now. Send Coupon. All items available free on attractive National , . .. _. .... ... w , Union deals. Let National Union Help You! National Union Radio Tubes are handled and recommended by more Service Dealers than any other make. See your National Union Jobber. Write for complete information. NATIONAL UNION RADIO CORPORATION. j\ hationai^M 570 Lexington Ave., New York City (RT736) w) union ^_ W< S7~^SS\^M .... Free offer for Webster-Chicago Model PA-417A .... Free offer for | Dealer's Name I Address | City State | 65