THE WIRELESS WORLD.

Otago Daily Times, Issue 19239, 1 August 1924, Page 4

THE WIRELESS WORLD.

NEWS AND NOTES. (By Magna Void [ltems of news, comment, suggestion*. *te.< will be welcomed by “Magna Vox.”i Dear Magna Vox. —Allow mo to compliment L. Dungoy on his interesting valve reception. As you know, you always ask for comments on achievements by radio amateurs. Why do they not submit to you for the benefit of others what their sets are capable of? Discussions of this kind give an impetus to other amateurs to do better. I am quite sure that many of the local amateurs have effected some performances of which they are proud, and they should submit them to you, so (hat other centres may see what Oiago amateurs can do. Included in my correspondence recently was a. letter from an Australian schoolboy. Can an amateur “trump” it? “Dear Mr O’Neill, —You may be interested to hear that your station comes in very well hero on one detector and two stages of Audio frequency. In fact, on Sunday night, July 13, I heard the sermon broadcasted from 4YA with a loop aerial. You are evidently using a fair amount of power, as I get you ©very timo you are ‘ on.’ I am using three dry sell valves. You do not seem to suffer from fading?—(Signed) T. F. Evans, Charles street, Blayley, New South Wales.—l am, yours etc.— F*. J. O'Neill, 4YA.”

The writer has been shown a. letter received bv Mr W. K. Line, formerly of High street, Motueka.. and now of Station 4YA, from the director of tho Chicago Tribune broadcasting statioii in which it is established that Mr Lane did receive the famous Chicago tests at the end of March last. The letter says; “There can bo no possible doubt that you received our station fairly continuously for a period of four hours.” Mr Lane used a De Forest reflex set and outdoor aerial. Tho Radio Society of Christchurch has decided to present Mr Ivan O’Meara, of Gisborne, with a silver cup in commemoration of his being the first amateur transmitter in New Zealand to establish intercommunication with either North or South America. It will b© remembered that Mr O’Meara, a few weeks ago, maintained a Morse conversation with an Argentine amateur. Melbourne, Adelaide, and Perth will each shortly have a high-power broadcasting station in operation. Tho Melbourne station will work on 1720 metres, and Perth on 12S0 metres wave-length. New Zealand amateurs with suitable receiving sets should bring in tho music from each, of the big Australian stations. HEART BEATS BROADCASTED. Heart throbs, the interesting demonstration of the super sensitivity of Dr Phillips Thomas’ glow-discharge microphone, whereby heart beats were broadcasted from Westinghouso Station KDKA. recently, reechoed over tha whole of North America and probably on the European Continent. The test of heart beats was heard from Maine to California, and from Canada to Mexico, and in some points in Great Britain according to reports received by the Westan ghousa Company. Owing to (he fact that heart beats have such a low period of frequency, as compared to the voice in speech or song, or to musical instruments, it is exceedingly difficult to find any “pick-up” to properly register them. After a long series of tests with the Thomas “ultra-audible” microphone, it was determined that this form of “pick-up” had the proper sensitivity to record the heart beats. Even then there was almost a continual testing of the apparatus far some weeks before the actual event was broadcasted. Broadcasting the heart boats was an interesting demonstration, to thousands. How tho actual equipment was made to operate is also interesting. The apparatus necessary for the proper pickup of the beats was in the Westinghouso research laboratory. There was installed the amplifying apparatus, which is used with all microphone “pickups,” the microphone itself, and a telephone lino to the broadcasting station in East Pittsburgh. Tho amplifying apparatus was arranged by Dr Thomas, and consisted of a number of vacuum tubes balanced with other tubes. : In the arrangement the apparatus was so hooked-up that tho high frequencies were eliminated. Tills was done so that extraneous noises which might occur in tile room wore eliminated and thus the heart beats made to register more clearly. Then, in tho actual broadcasting of (he boats, the microphone was placed just above the heart of the subject and (he sound, impulses registered. These heart beats, sent out by KDKA, are said to be the faintest sounds ever picked up by a radio microphone and intensified so clearly as to be audible to all listeners. To those who heard the heart heats tho pound was most unusual. One radio enthusiast stated that tho heart beat broadcasting sounded to him something like the telephone when tbo operator rings a busy signal. Others compared (he sound to other familiar noises. The s u person si bi vi ty of Dr Thomas’ microphone has made it the subject of a considerable discussion in the scientific world, so much so that physicians, biologists, and others are endeavouring to find means of applying the instrument to their own problems. THE DE FOREST lITIGATION. The radio industry was fairly thrown into a state of frenzy early lash month when Dr Leo De Forest was given control of the oscillating vacuum tube patents by the Court of Appeals for (he district of Columbia (says an exchange). The decision giving Dr De Forest these rights .terminated a seven-year legal battle and affects vitally practically every part of the radio industry in the United States. According to the decison handed down. Ur De Forest gets not only the control of the vacuum tube oscillators as used for transmitting, but also exclusive patent rights over tho so-called feed-back circuit, which will bring the tickler feed-lack regenerative circuit and the oupcr-Hoterodyne circuits under his control. As a matter of fact, attorneys are well agreed that in any case where a vacuum tube is used as a generator of alternating currents of any frequency that use will bo subject to tho Do Forest patents. A FAR-REACHING DECISION. Tho effect of this decision is obvious, since, at tho present time, all tubs transmitting stations being manufactured and installed in the United States will come under the control of Dr Do Forest’s patents. Those firms engaged in the manufacture of transmitting sets, regenerative and SuperHeterodyne receivers, will have to make their peace with Dr De Forest, and their further use of the oscillating auction in any form will depend entirely on the doctor’s goodwill. Whether they will bo granted licenses to continue their manufacture or not is a question that cannot be answered at present writing. It is positively certain that there will be no end of litigation brought, with a view to straghtoning out this tangle, and it is a tangle, since all future vacuum tubs transmitters-—this includes all broadcast stations —must Bo mad© only with tho sanction of Dr De F orest. HISTORY OF THE LITIGATION. The history of the litigation which resulted in this derision is by no means uninteresting. The fight started in March, 1917, with tho filing of an infringement suit’in New York against Dr Do Forest by the Wostinghouso Company, which, at that time, was in control of tho Armstrong patents for generating continuous waves by means of a vacuum tube—tbo patent which was given to Dr De Forest by tho decision. Shortly after (his case was filed a third claimant went, before tho patent office in Washington, claiming tho discovery of tho same idea. At that time there was still a fourth claimant contesting his own discovery. The result was that the Commissioner of Patents issued a Writ of Interference which directed all four of the claimants concerned to take their case to court and obtain a legal decision as to the rightful ownership of the feed-back oscillator idea. These four claimants were Dr De Forest, Mr Alaxander Meissner, a German inventor. Dr' Irving Langmuir, of the General Electric Company, and Mr Edwin H. Armstrong. , The first decision against Dr De Forest was handed down by Judge Mayer, of New York. The case was appealed and Dr L)o Forest lost again. It was then taken before the three patent office tribunals, from where it was appealed to the court of final authority which handed down last month’s decision. INVENTION NOT DISPUTED. Tho question was never one of invention. From tho first entry of the litigation it was admitted by all the attorneys concerned that Dr Do Forest had originally discovered tho idea. The most important single piece of evidence in tho case is tho two-page excerpt from tho note-book of Dr Do Forest’s assistant, Mr Van E'tten, which shows the original circuit and gives the oscillation result obtained from the hook-up. ’lho lower courts all maintain that the patent rights should go to Mr Armstrong because the lapse of timo between Dr De

Forest’s original conception of the idea August 6, 1912, and the time of his filin application for a patent covering it wa sufficient proof to establish tho fact tha: he had abandoned tho idea. One of th greatest points in favour of Mr Annstrom seemed to bo that Dr De Forest did no mention the use of tho oscillatory circa" for radio work at the time of discovery Mr Armstrong’s application for patent co: tains specifically the radio application c the system. The court which, banded down the late decision, however, took tho position th; since Dr De Forest was investigating t! use of the vacuum tube as tolephoi amplifier and repeater in order to obtab funds to carry on his other research wo; at the timo of his discovery, the lapse i time before, tho filing of the patent apphe tion did not actually constitute abandon merit.