Radio Broadcast (May 1929-Apr 1930)

. RADIO BROADCAST ADVERTISER. Single Control Perfect convenience in operation, with a tremendous gain in selectivity and sensitivity — that's what has been accomplished in the new S-M receivers. Newly developed shielded coils make possible, with straight single control, a degree of selectivity never before achieved, even uiith multiple controls or verniers. One tuning control, one volume control, an on-off switch — that's all. All these receivers have push-pull 245 output stages, and both broadcast receivers embody the latest band-selector tuning. AU-A. C. Operation These receivers are absolutely allelectric — even the 735 short-wave set, the first of its kind ever offered on the market. Power supplies are built into the receivers — not separate. The full advantages of the new a. c. screen-grid tubes are secured. The characteristic superior S-M tone quality, distancerange, and selectivity are in these receivers as never before, due not alone to band-selector tuning but also to still greater refinements of design and accuracy of manufacture. S-M Speakers and Power Amplifiers Nothing more beautiful in sound reproduction has ever been heard than the new S-M dynamic speakers, when supplied from a powerful S-M push-pull audio amplifier — giving straight-line amplification from 5000 cycles down even to below 50. These new medium-voltage highpower two-stage amplifiers, using 245 tubes in push-pull are built into the 722 and 735, and an extra high-grade Clough-system amplifier is obtainable separately, as the 677. Beautiful Cabinets The handsome new 707 table model shielding cabinet, finished in_ rich crystalline brown and gold, suitable for 722, 735, or 735DC, is only $7.75. Special arrangements have been made whereby these receivers may be housed in magnificent consoles especially adapted to them. Be sure to send for the new Fall S-M General Parts Catalog, for details of these cabinets. New S-M Custom Receiver Designs Shatter All Records 722 Band Selector Seven Providing practically all 1930 features found in most new $200 receivers, the S-M 722 is priced absurdly low in comparison. 3 screen-grid tubes (including detector), band-filter, 245 push-pull stage — these help make the 722 the outstanding buy of the year at $74.75 net, completely wired, less tubes and cabinet. Component parts total $52.90. Tubes required: 3 — '24, 1— '27, 2— '45, 1— '80. 712 Tuner Far more selective and sensitive even than the Sargent-Rayment 710, the new single-control 712 with bandfilter and power detector stands far beyond competition regardless of price. Feeds perfectly into any audio amplifier. Tubes required: 3 — '24, 1 — '27. Price, only $64.90, less tubes, in shielding cabinet. Component parts total $40.90. 677 Amplifier Superb push-pull amplification is here available for only $58.50, less tubes. Ideal for the 712. Tubes required: 2 — '45, 1 — '27, 1— '80. Component parts total $43.40. 735 ShortWave Receiver A screen-grid r. f. stage, new plug-in coils covering the bands from 17 to 204 meters, regenerative detector, a typical S-M audio amplifier, all help to make this first a. c. short-wave set first also in performance. Price, wired complete with built-in power unit, less cabinet and tubes, only $64.90. Component parts total $44.90. Tubes required: 1 — '24, 2 — '27, 2 — '45, 1 — '80. Two extra coils, 131P and 131Q, cover the broadcast band at an extra cost of $1.65. Adapted for battery use (735DC) price, $44.80, less cabinet and tubes. Component parts total $26.80. Tubes required: 1 — '22, 4 — '12A. Did You Get the Red-Hot News in the July RADIOBUILDER? Keep up-to-date on Silver-Marshall progress; don't be without THE RADIOBUILDER. New products appear in it in advance of public announcements — all of the receivers and cabinets above were described in detail and illustrated in THE RADIOBUILDER for July. Many hints on operating and building appear in it. Use the coupon. It Looks Like a Big Year For S-M Service Stations Custom-builders using S-M parts have profited tremendously through the Authorized S-M Service Station franchises. Silver-Marshall works hand-in-glove with the more than 3000 professional and semi-professional builders who display this famous insignia. If you build professionally, let us tell you all about it— write at once! SILVERMARSHALL, Inc. 6403 West 65th St., Chicago, U. S. A. IvorMarshall, Inc. 6403 West 65th Street, Chicago, U. S. A. .... Please send me, free, the new Fall S-M Catalog; also sample copy of The Radiobuilder. For enclosed in stamps, send me the following : . . . . SOc Next 12 issues of The Radiobuilder $1.00 Next 25 issues of The Radiobuilder S-M DATA SHEETS as follows, at 2c each: . .No. 3. 730. 731. 732 Short-Wave Sets . .No. 4. 255, 256, etc.. Audio Transformers . .No. 5. 720 Screen Grid Six Receiver . .No. 6. 740 " Coast-to-Coast" Screen Grid Four . .No. 7. 675ABC High-Voltage Power Supply . .No. 8. 710 Sargent-Rayment Seven . .No. 9. 678PD Phonograph-Radio Amplifier . .No. 10. 720AC All-Electric Screen-Grid Six . .No. 12. 669 Power Unit (for 720AC) . .No. 14. 722 Band-Selector Seven .No. IS. 735 Round-theWorld Six . .No. 16. 712 Tuner (Development from the Sargent-Rayment) . .No. 17. 677 Power Amplifier for use with 712 Name. • SEPTEMBER 1 929 • • 3 03