Radio Broadcast (May 1929-Apr 1930)

.RADIO BROADCAST ADVERTISER. Now — All-Electric ShortWave Reception The new S-M 735 Round-the-World Six brings every marvel of the lowwave bands within the perfect convenience of a. c. operation. A 224 screen-grid tube is connected so as to produce 2J/£ times greater amplification than the '22; the a. f. amplifier (245 push-pull) is free from hum, even in distance reception. Four plug-in coils cover from 16.6 to 200 meters. Two extra coils (cost $1.65) cover the broadcast band, with an altered connection built into the coil so as to greatly increase selectivity. Yet the 735 is low-priced — $64.90 net, wired complete with built-in power unit; the component parts total $44.90 net. Tubes required are: 1— '24, 2— '27, 2— '45, and 1— '80. 735DC, for battery use only, $44.80 net less tubes and cabinet. Tubes required: 1 — '22, and 4 — '12A. Component parts total $26.80 net. Either set fits perfectly in any of the cabinets referred to at the right. BandL '-Selector Tuning 3 A. C. Screen-Grid Tubes Custom~Built9 $74.75! AS trim and stylish-looking a one-dial set as was ever built to "sell on looks" — yet embodying such extreme performance as only Silver-Marshall can build into a set with three screen-grid tubes, band-selector tuning, and even screerugrid power detection — five times as efficient as '27 power detection. Four tuned circuits — highly shielded — an audio amplifier combining resistance coupling and 245 push-pull — complete built-in ABC power unit — chassis only 18%" by 9V2" — all at the price of $74.75 net, less tubes and cabinet, in the S-M 722 Band-Selector Seven. Tubes required: 3 — '24, 1 — '27, 2 — '45, and 1 — '80. Component parts total $52.90 net. For use with any 90-120 volt d. c. electro-dynamic speaker. Ideal for mounting in any of the cabinets mentioned below. Up-To-The-Minute Cabinets S-M 707 metal shielding table cabinet in beautiful crystalline brown and gold for 722 or 735, $7.75 net. Three beautiful console cabinets, adapted especially for mounting S-M 722, 735, or 712 with 677 by the I. A. Lund Corporation, are available from leading supply houses: see the new S-M Fall Catalog. Surpassing the Famous Sargent-Rayment Seven You know the Sargent-Rayment Seven — universally found to be the most sensitive broadcast receiver ever developed. Here, in the new 712 Tuner, is every feature of the 710 Sargent-Rayment — the five tuned circuits, the ultra-perfect shielding — the extra-fine r. f. coils — all built into an all-electric strictly single-dial tuner, with band selector tuning and power detection. Tubes required: 1 — '27, 3 — '24. Completely wired in satinfinish metal shielding cabinet, less tubes, $64.90 net. Works into any audio amplifier. Component parts, including shielding cabinet, total $40.90. Fits beautifully (with controls central) in any cabinet with space 18)^ by by 7ys-inch high. New 677 Amplifier An ideal audio amplifier for the 712 is the new S-M 677. Fully equipped with the famous Clough system (in push-pull) the 677 takes radio or phonograph input; supplies all ABC power required for the 7 12 (2 volts a. c, 180 volts B). Tubes required: 1 — '27, 2 — '45, 1— '80. Completely wired less tubes, $58.50 net (or for 25 cycles $72.50). Component parts total $43.40. Over 3000 Authorized S-M Service Stations are being operated; many are proving highly successful and profitable. The nearest one is ready to serve you if you want a custom-built set; write us for address if you do not know it. If you build professionally and do not have the S-M Service Station franchise — write us. Complete circuit diagrams of the 722 and 735 were first published in the RADIOBUILDER for August. Valuable suggestions on building and servicing are to be found in every issue. Use the coupon. SILVER'MARSHALL, Inc. 6403 West 65th St., Chicago, U. S. A. F" I Sil II Silver-Marshall, 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 : .... 50c 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 PhonographRadio Amplifier No. 12. 669 Power Unit No. 14. 722 Band-Selector Seven . . . No. 15. 735 Round-the-World Six . . . .No. 16. 712 Tuner (Development from the Sargent-Rayment ) . . . .No. 17. 677 Power Amplifier for use with 712 • OCTOBER 1929 • • 313