WIRELESS WORLD.

Taranaki Daily News, 20 September 1924, Page 12

WIRELESS WORLD.

A NEW INVENTION. REMARKABLE APPARATUS. (By “Honeycomb.”) The Westingin ■ Electric Manufacturing Company ci New York announce that the perfection of an electric ultraaudible microphone has been achieved by Dr. Phillips Thomas. This apparatus will allow scientists to record sound vibrations which are at present too faint or rapid for the human ea. to catch. While the invention was only in its experimental stage, Mr. S. M. Kintner, Director of Research for the Westinghouse Company, stated that the microphone was successfully used to transmit by wireless the human voice’s highest notes and those of musical instruments. Now, however, it could be used by vessels at sea to pick up the warnings of foghorns or other .sounds beyond the scope of the human ear. Also it had been shown to be of great use in studying the sound vibrations of the organs of the body such as the brain and Um heart, and even to picking up the sounds made by tiny insects. “The ultra-audible microphone ■will do for the ear what the microscope does for the eye,’’ Mr. Kintner concluded.

With a little care and thought it fa surprising how much longer a battery will last than without the attentions Most batteries have a notice attached to them giving particulars as to their care, but how many people pay attention to these? Distilled water must be added frequently, so as to keep the plates covered all the time. This fa often allowed to slide. Water should always be added to the battery before charging, as the action of this will make it evaporate a little. Do not read from the hydrometer immediately after adding the water, as it will not be accurate. Do not test the charge by shorting the poles; use a meter, or, better still a hydrometer. An “A” storage battery should never be completely discharged, and if ever completely discharged should be immediately recharged, otherwise the plates will sulphate. The sulphation on the plates will harden and the service life of the battery will bo reduced 75 per cont. It would also be necessary to remove th© electrolyte in the battery ' and replace it with a new solution. A | battery should not be discharged below 35 to 05 per ©ent. of its rated ampere hour capacity. TUBE MANUFACTURING UNCHANGED. Rumours have been current in radio circles, says World Wide Wireless, ti»e staff journal of the Radio Corporation of America, that the recent expiration of one of the vacuum tube patents under which the Radio Corporation of America has manufactured and sold Radiotron vacuum tubes would legalise the manufacture and sale of three element tubes of present-day construction generally. The Radio Corporation of America has issued the following statement, which indicates that with the expiration of the patent the tube manufacturing wnl remain practically unchanged:—*‘The expiration on January 15, 1924, of vacuum tube patent No. 841387 will not permit the general manufacture, sale, importation or use of three-element vacuum tubes as generally constructed, in which the grid or its equivalent fa interposed or located between the filament and the plate This type of vacuum tube is still covered by U.S. Letters Patent No. 897532, under which Radiotrons are manufactured and sold to the public. This latter patent has been sustained by the oourtß, and unlicensed radio tubes have been held by the courts to be infringements of the patent.”

Clean away any excess soldering paste from the terminals of your «et with alcohol and gave yourself a lot of trouble in finding out what is wrong with the set. A small quantity of vaseline taken on the finger and rubbed on the contacts of a switch wUi keep the contacts from wearing and grinding themselves away. Contrary to what one would naturally think, this also injures a better electrical contact. This “stunt” fa used in most of the large electrical research laboratories on delicate measuring instruments.

American amateur station 3BEI says the plate of hfa detector tube is getting very rusty from receiving so many damped oscillations. Another reason why there should be no spark seta. (QST). REVISED RADIO REGULATIONS. Many receiving sets howl on the slightest provocation. This is almost due to excessive inductance in the plate circuit. In the case of a set usiing a tickler the cure fa to remove turns. When using a variometer one can remove turns from both the rotor and the stator or use a rotor that does not fit the stator so closely. Excessive resistance in the secondary circuit will almost always cause to go in and out of oscillation very violently. In such cases the “howling point” fa always close to the oscillating point, and the set becomes very unpleasant to handle. The cure fa to lower the resistance of the secondary circuit by using a good coil and a good condenser and coupling it to the antenna. A shunting condenser of at least .001 m.f. should also be placed in the platt circuit. The University of Illinois, U.S.A., recently successfully transmitted music without employing a “carrier” valve, from it» broadcasting station. WRM. This is a revolution in transmission and no doubt has attracted a lot of attention among American experts. The proposed revised regulations governing radio in New Zealand are not embodied in the Bill to be presented to Parliament. The Bill provides for certain amendments in the Post and Telegraph Act to enable the authorities to licen.se and pay over portion of the list-eners-in license fees to the broadcasting company to conduct the four powerful stations. One is to be erected in radio districts of Auckland, Wellington, Canterbury and Otago. Any revision of the present regulations would be done by Order-in-Council. A receiving radio typewriter, invented by an American, attained an accuracy of 994 per cent., at 65 words per minute during a recent test in New York. A transmitter of 200 watte power is employed working on a wave length from 00 to 150 metres. THE AUSTRALIAN BOOM. Just as America and then Britain did, Australia has now struck the wireless boom that fa affecting all countries. It

i; many months now since th© famous “sealed set” regulations marked the first phase of Government regulation of broadcasting for our nearest neighbour, and the conditions then laid down were announced as the best in the world, avoiding all the mistakes and friction tlvat other countries had experienced. The sealed set system was doomed from within a month of its inception, and ere long its regulations were openly flouted. To-day, the new conditions framed under Government control have met with almost unanimous approval, and it fa contended that they are the most practical of any country. Time, alone, will justify this contention. Their effect, however, has been astounding even to the most far-seeing radio enthusiasts, and it hae caught business men napping. Such fa the abnormal demand for radio apparatus in Australia to-day that it would ‘be exceedingly difficult in Sydney at the present time to buy the complete parts for practically any circuit that one would wish to construct. The demand for radios has been phej nomenal, and one company alone is sending them out at the rate of two thousand five hundred per week. Australia has been badly bitten by what fa known as the bug, and, incredible as it may seem, there have been several im-tances of queues being formed outside the shops of wireless dealers.