Radio Broadcast (May 1927-Apr 1928)

RADIO BROADCAST ADVERTISER 257 Tone Control from your Easy Chair The New No. 3 ModirpluCjr With 20 Feet of Cord Just lounge in your easy chair, and let the program come in smoothly modulated as it changes in character. No more jumping up to adjust the dials every time the station changes from vocal to orchestration. Simply tune with your dials to maximum strength and clarity of station, then from your easy chair, with 20 feet of cord, use Moduplug No. 3 to smooth the reception down to any degree of tone, without changing the ratio of high and low notes. Centralab Modu-Plug gives any degree of volune from a whisper to maximum. Can also be used to provide a very convenientmethod of connecting two speakers in series at some distance from the receiving set. No 3, $3.00; Regular Cord Type or Jack Type, each §2.50. All mailed C. O. D. Centralab Power Rheostat This sturdy unit is a "knock-out" for warp-proof, heat-proof performance in socket power circuits. The heat-proof characteristic permits continuous operation at temperatures of 482° F. and beyond. Special design and construction assure this. The resistance wire is wound on metal core, asbestos insulated. The wire is firmly held in position at all times because the metal core will expand under heat in the same degree as the wire. This provides a smooth acting control under all conditions. Smooth regulation is further insured by narrow resistance strips. The narrow width gives small resistance jumps per turn. Compact 2" diameter; 1" behind panel. Single hole mounting. Bakelite knob. Ohms — 500,250, 150. 50, 15, 6, 3, .2, .5— price, $1.25. Can also be furnished as a potentiometer. At dealer's, or CO. D. Send postal for new circuit literature. Tou need this ideal Power Rheostat. Central Radio Laboratories 22 Keefe Ave., Milwaukee, Wis. I CT^LHE list of kits herewith is printed as an exten\~y sion of the scope of the Service Department of Radio Broadcast. // is our purpose to list here the technical data about kits on which information is available. In some cases, the kit can be purchased from your dealer complete; in others, the descriptive booklet is supplied for a small charge and the parts can be purchased as the buyer likes. The Service Department will not undertake to handle cash remittances for parts, but when the cou pon on page 258 is filled out, all the information requested will be forwarded. 201. SC Four-Tube Receiver — Single control. One stage of tuned radio frequency, regenerative detector, and two stages of transformer-coupled audio amplification. Regeneration control is accomplished by means of a variable resistor across the tickler coil. Standard parts ; cost approximately $58.85. 202. SC-ll Five-Tube Receiver — Two stages of tuned radio frequency, detector, and two stages of transformer-coupled audio. Two tuning control. Volume control consists of potentiometer grid bias on r.f. tubes. Standard parts cost approximately $60.35. 203. "HI-Q" Kit — A five-tube tuned radio-frequency set having two radio stages, a detector, and two transformercoupled audio stages. A special method of coupling in the 1 .f. stages tends to make the amplification more nearly equal over the entire band. Price $63.05 without cabinet. 204. R. G. S. Kit — A four-tube inverse reflex circuit, hav ng the equivalent of two tuned radio-frequency stages, detector, and three audio stages. Two controls. Price $69.70 without cabinet. 205. Pierce Airo Kit — A six-tube single-dial receiver; two stages of radio-frequency amplification, detector, and three stages of resistance-coupled audio. Volume control accomplished by variation of filament brilliancy of r.f. tubes or by adjusting compensating condensers. Complete chassis assembled but not wired costs $42.50. 206. H & H-T. R. f. Assembly — A five-tube set: three tuning dials, two steps of radio frequency, detector, and 2 transformer-coupled audio stages. Complete except for baseboard, panel, screws, wires, and accessories. Price $30.00. 207. Premier Five-Tube Ensemble — Two stages of tuned radio frequency, detector, and two steps of transformer coupled audio. Three dials. Parts assembled but not wired. Price complete, except for cabinet, $35.00. 208. "Quadraformer VI" — A six-tube set with two tuning controls. Two stages of tuned radio frequency using specially designed shielded coils, a detector, one stage of transformer-coupled audio, and two stages of resistancecoupled audio. Gain control by means of tapped primaries on the r.f. transformers. Essential kit consists of three shielded double-range "Quadraformer" coils, a selectivity control, and an "Ampitrol," price $17.50. Complete parts $70. 1 5. 209. Gen-Ral Five-Tube Set — Two stages of tuned radio frequency, detector, and two transformer-coupled audio stages. Volume is controlled by a resistor in the plate circuit of the r.f. tubes. Uses a special r.f. coil ("DuoFormer") with figure eight winding. Parts mounted but not wired, price $37.50. 210. Bremer-Tully Power-Six — A six-tube, dualcontrol set; three stages of neutralized tuned radio frequency, detector, and two transformer-coupled audio stages. Resistances in the grid circuit together with a phase shifting arrangement are used to prevent oscillation. Volume control accomplished by variation of B potential on r.f. tube. Essential kit consists of four r.f. transformers, two dual condensers, three small condensers, three choke coils, one 500.000-ohm lesistor, three 1 500-ohm resistors, and a set of color charts and diagrams. Price $41.50. 212. Infradyne Amplifier — A three-tube intermediatefrequency amplifier for the super-heterodyne and other special receivers, tuned to 3490 kc. (86 meters). Price $25.00. 213. Radio Broadcast "Lab" Receiver — A four-tube dual-control receiver with one stage of Rice neutralized tuned-radio frequency, regenerative detector (capacity controlled), and two stages of transformer-coupled audio. Approximate price, $78.15. 214. LC-27 — A five-tube set with two stages of tunedradio requency. a detector, and two stages of transformercoupled audio. Special coils and spec al means of neutralizing are employed. Output device. Price $85.20 without cabinet. 215. Loftin-White — A five-tube set with two stages of radio frequency, espec ally designed to give equal amplification at all frequencies, a detector, and two stages of transformer-coupled audio. Two controls. Output device. Price $85.10. 216. K.H.-27 — A six-tube receiver with two stages of neutralized tuned radio frequency, a detector, three stages of choke-coupled audio, and an output device. Two controls. Price $86.00 without cabinet. 217. Aero Short-Wave Kit — Three plugin coils designed to operate with a regenerative detector circuit and having a frequency range of from 19,990 to 2306 kc. (1 5 to 130 meters). Coilsand plugonly, price$i2.50. 218. Diamond-of-the-Air — A five-tube set having one stage of tuned-radio frequency, a regenerative detector one stage of transformer-coupled audio, and two stages of resistance-coupled audio. Volume control through regeneration. Two tuning dials. 219. Norden-Hauck Improved Super 10 — Ten tubes; five stages of tuned radio frequency, detector, and four stages of choke and transformer-coupled audio frequency. Two controls. Price S260.00. 220. Browning-Drake — Five tubes; one stage tuned radio frequency (Rice neutralization), regenerative detector (tickler control), three stages of audio (special combination of resistance and impedance-coupled audio). Two controls. Celatsite Wire A cable of fine, tinned copper wires with non-inflammable Celatsite insulation. Ideal for sub-panel or point-to-point wiring. Strips easily, solders readily. Nine beautiful colors; sold only in 25 ft. coils, in cartons colored to match contents. Acme Celatsite Wire Tinned copper bus bar hookup wire with non-inflammable Celatsite insulation, in 9 beautifu 1 colors. Strips easily, solders readily, won't crack at bends. Sizes 14, 16, 18, 19; 30 inch lengths. Spaghetti Tubing Oil, moisture, acid proof; highly dielectric — used by leading engineers. Nine colors, for wire sizes 12 to 18; 30 i nch 1 engths. (We also make tinned bus bar, round and square, in 2 and 2% ft. lengths.) Stranded Enameled Antenna Best outdoor antenna you can buy. Seven strands of enameled copper wire. Presents maximum surface for reception, resists corrosion; this greatly i mproves the signal. Outside diameters equal to sizes 14 and 16. (We also offer solid and stranded bare, and stranded tinned antenna.) Loop Antenna Wire Sixty strands of No. 38 bare copper wire for flexibility, 5 strands of No. 36 phosphor bronze to prevent stretching. Green or brown silk covering; best loop wire possible to make. Battery Cable A rayon-covered cable of 5, 6, 7,8 or 9 vari-colored Flexible Celatsite wires for connecting batteries or eliminator to set. Plainly tabbed; easy to connect, an orderly appearance. Gives set Send for folder THE ACME WIRE CO., Dept. B New Haven, Conn. MAKES BETTER RADIO