Radio Broadcast (May 1927-Apr 1928)

174 RADIO BROADCAST ADVERTISER fipLGNAYOX Speaker Quality 'Plus for the Slectric Set and Electric Phonograph Guilder ALTERNATING CURRENT SOCKET POWER STEPPEDUP A C ENERGY RECTIFIED • RECTIFIED FILTERED; Oyl PUT ENERGY ; DIRECT CURRENT PULSATING DI-' RECTCUBRtNT. SPLIT UP ; INTO VAR'i 10US VOL' TAGES : A RECTIFYING FILTER CIRCUIT A TUBE o TO 110 VOLT A.c. SUPPLY REPLACE OR * SAVE THIS CHOKE BY USING THE FIELD OF THE MAGNAVOX „ R,5 UNIT " TO RADIO OUTPUT TRANSFORMER The field of the Magnavox type R-5 Electro-dynamic speaker unit provides the highest class high resistance choke for A. C. rectifier and filter units. The current passed energizes the field for its function as a speaker. Only the electro-dynamic type speaker can give the wonderful quality of radio reception possible with modern sets and broadcasting. Magnavox R-5 Electrodynamic Speaker-Unit Price #55.00 Easily installed in radio or phonograph cabinets. Beverly Model Table type cabinet, mahogany finish, curved top, equipped with R-5 Unit $80. Aristocrat model, floor type, butt burl walnut panels, two tone mahogany legs and corners, equipped with R-5 unit $90. Write for full description of this and other units and complete electro-dynamic type speakers. THE MAGNAVOX CO. Oakland California 1315 So. Michigan Ave. Chicago Hirers THE paragraphs below represent in part interesting announcements of new products which have been received by Radio Broadcast from important manufacturers within recent weeks. Many of our readers will welcome this section where they can find concise information on the interesting new offerings. Space does not permit the more complete discussion and remarks which many of these announcements deserve. Readers can preserve these columns and those which will appear in the future in this section of Radio Broadcast. Further information on the apparatus described may be obtained by writing to the Service Department of Radio Broadcast. It is hoped that those readers who write the manufacturers directly will refer to this department when writing. — The Editor. New Offerings by Amsco Products Co. Inc. Extra-spaced variable condensers, known as Duospace to be used in power oscillators, small transmitters or in receiving circuits where the tVo inch spacing between rotor and stator plates contribute toward extremely accurate alignment of single-control circuits. Samson Electric Co. Power chokes with an inductance of 30 henries under the following conditions: No. 30, 30 milliamperes, d.c. resistance 470 ohms, price $5.00; No. 380, 80 milliamperes, d.c. resistance 200ohms, price $ 1 1 .00; No. 3 12, 120 milliamperes, d.c. resistance 290 ohms, price $12.00. Power transformers, No. 132 rated at 40 watts, furnishes 200 volts plate supply at 80 milliamperes from 60 cycles, fitted with windings to furnish filament voltage for ux-280 and two 171's. Price, $ 1 5.00. No. 162, designed to furnish a 500-voIt plate supply to tubes such as the 210, rated at 75 watts, filament supply for ux-281 and 210. Secondary voltage, 725. Price, $19.00. No. 253, same as No. 132 but to be used on 25-cycle supply. Price $19.00. No. 256 same as No. 162 but to be used on 25-cycle supply. Price $27.50 No. 232, designed to supply 200 volts direct current to receiving set. Similar to No. 132 but supplies in addition filament current for five 226 type tubes, two 227, and two 171's. Rated at 100 watts. Price, $16.50. No. 262, similar to No. 232 except supplying power for a 210 amplifier. No. 463 furnishes a.c. voltage for all a.c. tubes. Has windings for 1.5-, 2.5-, and 5-volt tubes. Price, $14.50. No. 259 same as 463 except for 25 cycles. Price, $17.50. No. 217, rated at 20 watts. Supplies filament voltage for two 171's or two 2 10 tubes. Price, $12.00. Power block No. 713 to furnish necessary energy at 180 volts 50 milliamperes, rated at 30 watts, supplies filament windings for ux-280 and 171 tube, and contains chokes and transformer. Price, $24.50. No. 718, supplies 200 volts at 80 milliamperes. Otherwise same as No. 713. Price, $33.50. Jefferson Electric Mfg. Co. Output transformer with 30 inches of cord and equipped with telephone tip and pin type jacks. Model 395, price $6.00. Filament supply transformer, furnishing voltage for eight 1. 5-volt tubes, one 2. 5-volt detector tube, and two 5-volt tubes. Price $7.50. Plate supply transformer to be used with ux-280 rectifier tube, 5-volt center-tapped filament winding, 520 volt centertapped 125 milliampere plate winding, price $10.00. Combination filament and plate voltage transformer, price $15.00. Plate supply choke passing 125 milliamperes, price $6.00. Benjamin Electric Mfg. Co. New style of the well known Benjamin floating socket; also Y type socket for heater type tubes. Straight frequency-line condenser single hole mounting, No. 9080 capacity .00025. mfd. price $3.50; No. 9081 capacity .00035 mfd price $3.75; No. 9082 capacity .0005 mfd. price $4.00. Westinghouse Electric and Mfg. Co. Rectox A battery charger. Uses copper oxide rectifying elements providing full-wave rectification. Charges at f amperes, 6 volts. RADIO DEALERS Send for our catalog illustrating the products of over 100 radio manufacturers. WHOLESALE ONLY! F. D. PITTS COMPANY 219-223 Columbus Ave. BOSTON, MASS., U. S. A. Established 1919 BROWNING-DRAKE BLUE PRINTS? Write to Radio Broadcast Magazine Booklet Department Garden City New York $1.00 per set BRUNO QUARTZITE TUNING COILS have been repeatedly specified in new circuits for their high degree of efficiency, selecivity, and sensitiveness. The No. 99 Jr. Tuning Coil has been designed to be used with a .0005 mfd. condenser across the secondary winding. When used with the No. 99 TRF Coil, if the condensers have the same capacity, the two readings should be alike. Absorption losses are completely eliminated. Wavelength 200 to 575 meters. List price . . $5.50. The No. 99 Jr. TRF Coil when used in conjunction with a .0005 mfd. condenser will cover the entire wavelength band from 200 to 575 meters. Furthermore it is suitable for any circuit employing tuned radio frequency. List price $3.00. Both Coils are perfectly made and wound with green and orange silk covered wire on Quartzite — a special glass containing no metallic base. Get them from your dealer or write us. BRUNO RADIO CORPORATION Long Island City New York