Indianapolis Times, Volume 36, Number 266, Indianapolis, Marion County, 19 March 1925 — Page 20

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HIRES OF RADIO SEE RESEMBLE NERVESOF BODY Each Is Insulated With Membrane Coating, In the nervous system of the kuman body each nerve Is a conductor of a current or Impulse. Each Individual nerve is well insulated with a protective coating of fibrous membrane. If this coatinjf is in any way injured or destroyed, the whole Mflptem may be thrown out of balance HttJd will not function properly. If we picture the wires in a radio circuit as the "nervous systems” of a receiving set, it will be seen that in case proper care and thought has not been given the selection of the different wires that go to make the complete radio receiving set, or if improper or poor insulations are used, it is quite likely that disturbances will be set up that will result in the "system” not working smoothly. Signal Energy Minute The signal energy from far away stations may often be less than a millionth of a volt and it is. therefore, readily conceivable that even a alight resistance introduced into the receiving circuit might reduce or destroy signals. In ofder to obtain the best res Its it is advisable for the builder provide the most suitable conductor so that resistance and leakage are reduced to a minimum. It is, of course, impossible to state definitely or within narrow limits what is the cor.ec size of wire or what type of insulation is most suitable for this or that unit of any circuit. This is apparent when we

KBORADIO “Play as You Pay 99 1111111 l Every Radio buyer will find that he will need SERVICE. Without it much jjgjH of the pleasure of Radio will be lost ||J|l We give two weeks FREE service ■M with every Radio Set we sell. Our U3 service men are competent, experi18] enced Radio experts prepared to give IN our customers service at all times—night or day. •

QUALITY We offer only Radio Sets that we have thoroughly tested. Every set is guaranteed to work properly or money refunded.

RECEIVING SETS Adler Royal Neutrodyne (5 Tubes), Radiola Superheterodyne, Day Fan (4 Models), Globe (4 Models), Lafayette Neutrodyne. Prices sllß to S4OO. Our prices are for complete sets installed.

TERMS: 20% DOWN—B MONTHS To Pay Balance

Indianapolis Music House 134 North Pennsylvania 1 St. Open Evenings. • MA In 218a . rr . .

Antenna Like a Stove Pipe Hu NEA Service DAYTON, March 19.—What has been termed a "stove-pipe antenna” has been designed by Maj. Orln E. Marvel, radio engineer of this <^ty. The antenna consists of a wire wound around a mast, and looking from a distance much like a small smoke pipe. Marvel claims for it more height, better selectivity and greater volume. At the same time it replaces the long wires which are much harder to put up.

consider the present state of the science, which is really as yet more or less in the experimental stage. Choice is Wide For the building of the coll untis we have a large field of different types of magnet wire to select from: Plain enameled, single cotton covered, double cotton covered, single silk covered, double silk covered, cotton covered enameled, and silk covered enameled wire. The plain enameled wire formerly was one of the inofet popular types for winding of the earlier and simpler types of colls. It was soon found, however, that the disturbed capacity in coils wound with this type was extremely bothersome. The plain enameled v<re has. therefore, been discarded almost entirely for this purpose and the demand is now for the textile covered wires. The best results are obtained when using the double cotton covered or double silk covered types. This does not, nowever, apply to certain types of R. F. transformers or A. F. transformers where enameled wire is used exclusively. In such coils the space factor is of extreme importance and it is not practical for the fan to attempt to wind those coils with the ordinary means at his iVsposal. The number of turns In an audio frequency transformer, for eiample, run as high as 20,000. The high frequency iLitzl cable

THE INDIANAPOLIS TIMES

The Voice From 1 KYW

: ; . BS| ?? v^j, jj 111 / w • j|B^

Logan (Steve) Trumbulk chief announcer and head of the "World Crier” service, giving world news to radio fans each half hour from KYW, Chicago, is a playwright as well as a short-story author.

composed of a number of fine wires, each insulated with enamel, giving a liminated construction, has become very popular lately for the winding of variometers and varioeou piers for ise in R. F. circuits. These conductors effect a great reduction in distributed capacity and also practlcrJly eliminate eddy currents. For loop antennaes, a stranded bare wire consisting of 60 strands of No. 88 wire twisted with 5 strands of half hard phosphor bronze is especially suitable. The insulation may be a covering of cotton and over this a covering of silk, or It may have two servings of silk. •The ground wires need not, of course, be Insulated, but it is usual to have some sort of covering for appearance. It is advisable to use as heavy a wire as practical for the ground—l 2 or 14 B. & 9. gauge is suitable. Aims for Battery la>ads The battery leads should preferably be of the rubber covered braided conductor type. For the "A” battery No. 14 or 16 B. & S. gauge, and for "B” batteries No. 16 or 18 B. & S. gauge has been found satisfactory. Always use a flexible copper pigtail for this connection. A wiping contact may be good as first, but will son corrode and set up too much resistance. Loose Tube Contact When the vacuum tube does not fit properly in its socket, a toothpick or a match whittled down to form a wedge can be placed between the socket and the tube to hold it tightly in place. Radio in Hotel A Philadelphia hotel has a receiver in each of its 208 rooms and a loud speaker in each of the larger rooms. A telephone operator controls the reception. When Vacuum Tubes ‘Go West’ A dying vacuum tube generally becomes notey and the music distorted. Tubes will often lose their power to detect and amplify before they bum out. The symptom that a tube is "dying” is a gradual decrease in volume and the gradual disappearance of distant stations blending into a ranid decrease in volume. ■ " r Big “B" Batteries lave Longer Pry cell “B” batteries are rated according to ampere-hour capacity #nd also by weight. The same voltage may be delivered by one, three or five-pound batteries, but the heaviest ones will deliver the voltage over the longest period of time. Talks on Food Problems The University of Wisconsin has inaugurated a radio lecture course on home problems, broadcast every Monday evening at 7:45 through Its station, WHA. The lectures are given by Mrs. Nellie Kedzie-Jones, head of the home economics extension work of the college of agriculture Every Monday Night The University of Wisconsin radio station, WHA, Is conducting a course in food problems in home making. Every Monday at 7:45 p. m. the station broadcasts on 635 meters one of the aeries of lectures in this course. There are also correspondence The course may be taken up at any time and copies of the radio lectures will be supplied with each assignment^

NEW INVENTION IS USED Aviators Converse in Air Five Miles Apart. Rii Time a Special W ASHINGTON, March ID. According to reports to the War Department, two Army aviators at Dayton, Ohio, succeeded in talking to each other by radiophone while in the air and more than hve mill’s apart. The two ships were equipped with broadcasting and receiving apparatus for test, pur poses. It is the hops of the War Department eventually to equip all planes so that the pilot may carry on conversations while in the air. Spaghetti Insulators To secure ends of the wire on narrow coils, drill three holes a little larger than the diameter of the wire used. Through one of these draw the end of the wire and put a piece of stiff spaghetti over it. Now bend the spaghetti over and thread the free end of the wire through the small holes, forming one or more loops around the spaghetti. Windings for Headphones Headphones are the most sensitive when W'ound with a great many turns of very fine wire. Copper is the best wind of wire for this purpose, as it has a lower resistance than other forms of wire. The wire is usually insulated with a coating of enamel

Atwater-Kent Radio — Manufactured by one of tbe jMW most well - known manutheir guarantee and with the

Following are a few of the types and models carried in our Radio Dept.

ATWATER-KENT / RADIO No. 20 DeLuxe; 5-tube model. . Price $l2O

ATWATER-KENT RADIO No. 20 Cabinet; 5-tube model. Price SIOO

ATWATER-KENT RADIO Console Cabinet; built-in loud speaker; Louis XVI 6tube model. Price $350

ATWATER-KENT RADIO Console Cabinet, built-in Loud Speaker, 5-tube model. Price $2lO

Demonstration in your Lome if yon have the antenna or we full erect one at small cost. ■—Pettis radio and Vlctrola dept, fifth floor. Pettis Dry Goods Cos. The Store Est. 1853 JHn -. v

FOR THE NOTEBOOK Music ranks first as a broadcast feature. A piano makes an excellent indoor aerial. The prices of radio sets range from sl4 to $5,000. Stranded bare copper wire is generally more suitable for the aerial, and one wire is enough. A permanent magnet will retain its magnetism a long time if a piece of, steel is kept across the poles. The range of a receiving set should be based on the distance heard at any night at all under any atmospheric condition. Shield the back of the dials to overcome body capacity. The tinfoil should be grounded to the rotor of the eondesner, or the ground wire. A poor ground connection may cause a high loss of selectivity because of the increased resistance of the aerial circuit,- which broadens tuning. Smallest Studio What is said* to be the smallest broadcasting studio in the country is now being operated in Chicago weekly by station WJJD, Mooseheart, 111. ft’s at a famous case, from which entertainments are broadcast. Tent With Voltmeter The condition of the alkaline battery is tested by a voltmeter and not by a hydrometer. When fully charged each cell has a potential of 1.4 volts and drops during its use to 1.2 volts.

'Featured at Pettis

ATWATER-KENT RADIO No. 10 Open Set; 5-tube model. Price SBS

ATWATER-KENT RADIO Console Cabinet, built-in loud speaker; model 1100; 5tube model. Price $225

ATWATER-KENT RADIO Model No. 19. Cabinet; 4-tube model. v Price SBS

Terms can be had on all Radios without interest or charge.