Radio age (Jan-Dec 1925)

78 RADIO AGE for December, 1925 The Magazine of the Hour Non-Vibrant Ceramic Horn For EVERY Radio Set A stunning piece of furniture that restores order in the room where you have your Radio! No more cluttered table-tops, nor litter of equipment under-foot. No unsightly horn in evidence, either! This console has its own loudspeaker, inbuilt. It's out of sight, but with very apparent tonal SUperior'l The clearest tone pro4-',r*r. T?~ '.* 1 „~ ducer on the market. ties, tor it has Made of specilll com. the highest -de Position which defeats , j r vibration. veloped type or unit. With horn built of special non-vibrating, extra-hard, ceramic material. Produces clear non-vibrant tone. There's ample room for everything; space for largest A and B wet batteries — or battery eliminator—required for any home set; and for a big charging outfit, too. Finished in mahogany, or walnut color. Dainty design of parqueterie on two front panels. Top, 38 in. x 18 in. Substantially built; the product of a 40-year-old furniture maker. The price, forty dollars, is for the complete console and includes the loudspeaker horn and unit. Thousands of dealers are showing this artistic addition to home radio equipment. Rear View— Set Hooted Up The New Word in Radio In radio, "kilocycle" is gradually taking the place of "wavelength" says the Bureau of Standards, Department of Commerce. All listeners and users of sets will want to know and understand the new rating which increasingly governs their tuning in. The making or logging of dials is found to have certain advantages when in the newer terms. Already one of the oldest stations is announcing its broadcasts on the "kilocycle" or frequency rating. It is really quite simple, for frequency (waves per second) replaces wavelength (in meters). Just as a musician can vary the number of oscillations of his vocal chords but cannot control the length of the sound waves, which vary with the medium, so a radio station can vary the number of oscillations per second, and let the wavelengths be what they will. A high tenor "C" gives sound waves 2 feet in length but the standard rating is frequency, or pitch, in this case 512 vibrations per second. Frequency is the number of waves produced per second, the number of waves on the air after one second of transmission. "Kilocycle" means a thousand cycles, hence a broadcast on a 500-kilocycle frequency emits 500,000 radio waves per second. To aid radio amateurs and experts the Bureau of Standards is about to issue a table so that all can, at a glance, translate from the old rating by "wavelength" (in meters) into the new rating by frequency (in kilocycles), and vica versa. Radio waves travel with the speed of light, about 300,000 kilometers per second. This is the sum of all the waves emitted in one second. Dividing this by the wavelength gives the frequency; dividing by the frequency gives the wavelength. The bureau gives the simple rule to obtain the frequency when the wavelength (in meters) is known : Divide 300,000 by the wavelength in meters. The answer is in kilocycles. Likewise the other way around; divide 300,000 by the number of kilocycles to get meters. It is interesting that the ratio is the same both ways; 100 meters equals 3,000 kilocycles; 100 kilocycles is 3,000 meters. Inexpensive Tube Test Set Made by Jewell An interesting booklet, known as 15-A has just been issued by the Jewell Electrical Instrument Co., of Chicago, for the information of the radio trade and experimenters. The Jewrell Company has placed on the market a simple tube tester, known as Pattern 110, which should meet the demand for an inexpensive tube test set desired by many of the experimenters in the game, as well as the dealers. It is fully described in the 15-A booklet. New Coils New Condensers Easier Control Watch for the JanuaryRadio Age Model Set All — Stand; rd *X* ™ Types <» ~ $2.50 E V/////SSSS//SS//S/S//////S//////////S///S//S/////////////. ■/////////////////////////St*. ■'S////////////////S///S, ED ilQW RADIO TUBES f/ ™ Cleartron is the only radio S 5 tube sold under an Iron-Clad ! S Guarantee of perfect service g I" or instant replacement. ->» At All Reliable Dealer!. JJ — Write for Free six pact tube folder. mm ™ Hi-Contlrofl Model C-T 101A— 83.00. The mm «■ original Hi-Mu Tube for Resistance-Coupled JJ J^ Amplifiers. ^» 2 CLEARTRON VACUUM TUBE COMPANY = — Executive Offices. kftj « ~ 28 West 44th Street, New York City. — — Factories: West New York, N. J.. U. S. A. Birmingham. Eno. iiiiimmiiiiiiiiiiiiiiiiiiiiiiiiiiii For Better Keception iiiiiiiimiiiiiiiiiiiiiiiiiiiiiiimii * Tested and Approved by RADIO AGE * THE ACCURATUNE is ideal for coarse or extremely fine tuning, segregating even those stations now so closely grouped on the lower wave lengths; it brings them in with absolute precision. Volume and clarity are matters of course to the Accuratune. Quickly substituted without alteration of your set. MYDAR RADIO CO. 17 CAMPBELL ST., NEWARK, N. J. Accuratune