ON ALL WAVELENGTHS

Evening Star, Issue 20316, 26 October 1929, Page 8

ON ALL WAVELENGTHS

HIGH FREQUENCY CONTROL. FILAMENT RESISTANCE USED. Here is a method of controlling the high frequency amplification of a shielded grid or a neutralised stage that has been found to be an improvement on many occasions. The method used consists of a filament' resistance connected to the tube. With the resistance fitted to the circuit as shown in diagram, the maximum amplification is obtained when it is short-circuited and falls off as the resistance is included. The reason for this is than the temperature of the filament of 'the tube decreases with the current passed through it.

A smooth control of volume by this method will not follow in the case of a tube of the independently heated cathode type. There is a lagging tendency in these tubes preventing the temperature from reaching a steady value for a considerable interval, and therefore success does not attend any attempts to vary the filament current. Amateurs frequently move the resistance beyond the point where the desired volume is to be found and several seconds are then lost waiting for the steady state to bo reached. ABOUT TELEVISION. DIFFERENT ANGLES VIEWED. Germany is progressing in the world of television, and a Berlin station, Witzhhen, has been transmitting pictures for some months now. There has been good reception of the broadcasts with the normal local range of the station, while a magazine writer in England on several nights heard a peculiar note on the air which ' e could not account for until he learned that it was on the same wave as the Berlin station It was evidently the tele vision note from the station. The Baird engineers in London went a step further than hearing the note. They were successful in transforming the noise into images at their receiving laboratories, and _ although the images were a little indistinct they were quite recognisable. With the reproduction of the image another mile stone in the progress of television was reached. Baird television has already crossed the Atlantic, and with

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the reception of the German station it has brought Berlin within optical range. There is another side to television that perhaps has not yet reached consideration. Will it ever become a bad master? An Australian paper treats the subject in humorous vein, and states that it is one thing to be called I b another to bo seen. The voice over the air may bo very impressive, oven commanding, but if the talker is seen it may become very embarrasing and undignified to be seen in one’s “deshabille.” The paper also says that television is likely to destroy one’s privacy, but its introduction to an existing wireless set in an advanced form would be nothing short of a scientific marvel. Television has now reached as far as Australia. A party of citizens and pressmen visited a hotel in Melbourne recently to watch a demonstration of the Baird system by Major M'Lulich, F.R., Met. Soc. After the apparatus at the hotel had been examined by the party it was put into operation The transmitting plant was situated on the top floor of the same hotel, and when Major M'Lulich rang the operator on the house telephone the face of a lady artist appeared at a special window in the cabinet. By adjusting the tuning of the set Major M'Lulich was able to make the face clearly visible to all present. “Good afternoon, would you like mo to sing something?” were the words that issued from the loud speaker,_ and immediately the company recognised both the face and the voice as belonging to Miss Molly Mackay. When Miss Mackay had "sung a second artist played a violin solo ? but the necessity for bold ing her violin in position restricted the play of h . features. Only the heads of the artists could be seen. One little puppy was put before the disc on the transmitter, but ho just wagged his ears and refused to lift up his voice even in complaint. After the demonstration _ Major M'Lulich said he did not think the day had come when television would bo within the reach of the average listener. It was unlikely, he said, that anything would bo done with the Baird television in Australia just yet, for he had received word to sail for Home, where a merger of certain interests was imminent that would vitally affect the future of television. PATENT ON WORD “ DYNAMIC.” According to a patent decree, probably handed down by the United States Patent Office, the Magnavox Compan.v ■secures the exclusive use of the wore "dynamic” in connection with radii loud speakers, telephone receivers, am parts (states a San Francisco journal), the Magnavox Company advises tha. the “ dynamic ” trade mark has beer continuously used and applied to its merchandise since 1915. The rccogui tion of this trade mark by the patent office establishes the priority of Magnavox in the dynamic field. The company has also officially announced its sole right of the word “ dynamic.”

WITH COMMANDER BYRD. CONVERSATIONS WITH THE OUT SIDE WORLD. The article reprinted hero from the Listener In ’ may prove of interest to readers of these columns With a thermometer recording 84deg of frost ono would hardly expect human beings to look upon that temperature as a “harbinger of spring,” hut it ali depends on where you have been dur ing the winter, or so it would seem when ono listened in to the chats which the operators at W.F.A. carry on with the normal world from their wireless station on the Great Ice Barrier, at the Bay of Whales, on' the newly-named “ Little America ” base of Commandei Byrd’s Antarctic expedition. Tha operator has been telling his wireless friends in America and in New Zealand a few sidelights on the daily routine during the first signs of the passing of the long Antarctic night. It would seem that the changing of the seasons, both down there and here, is responsible for the magnificent manner in which the wireless arc coming through at the present time. The other night f read about 1,000 words of talk aud messages sent out from W.F.A. to America and New Zealand stations. Never once did the operator at Commander Byrd’s base have occasion to repeat the message—that is to say, ho sent the entire message straight through, and did not follow tho usual “ safety ” method of sending each word twice. Ho gradually speeded up until _ he was sending at a trifle under thirty words per minute. On all occasions when ho asked for acknowledgment of tho traffic from either the American or New Zealanci stations, he got “R.” “ 0.K.” (re ceived 0.K.) at once, and nothing had been lost or smashed by static and fading. . . Rather a good performance, isn t it? Instantaneous contact with the world in a conversationalistic sense at a rapid and fluent speed. It can only be gauged in its true value when cno recalls that the former explorers down there —Amundsen, Scott, Mawson, and others—once their supply ships left the last port of civilisation, were “gone surrounded by a vast wilderness of silence for years. News of tho outei world and their folks at home, the news of the day, the ability of adjust requirements for future supplies when the ice pack opens again next season md permits a return of supply ships, were all entirely cut off formerly. But mt so to-day. Thanks to the small ’’ort-wave wireless installation, which ■nthfully “ perks ” out its messages •om a cold of about 100 degrees below ■cozing, all this has changed, and in ■bout one second a reply can be had ■Tom the TT uited States of America, and a long message in a couple ol minutes. Some of the conversation from WFA has been bright and humorous. The other night he was working with a “ W 6 ” amateur in the States, and said: “It’s 52 below here to-day. It looks as if spring is here. Hi!” (hi is the wireless equivalent of laughter). Gout-inning, he agreed with ■ the remark of his American friend, that. “ Yes, it seems an unusually good night t-o-nmht —yon should be able to work some good ‘ DN ’ (DX is the abbreviation for long-distance communication) to-night,” and then ho added a couple of hi’s. When you come to think of it, there was a grain of humour in that remark. since they were working almost tho longest circuit this little old world of ours can provide. Later on he was chatting to New Zealand, and said: “The temperature went down to 5S below this morning, and there has been a quite hefty wind all dav, so I staved inside this p.m. faY-ernoon). Sorry we won’t be able to test the portable set to-night, as the 1 iTmk ’ is out in a snowhonse igloo about 200 ft away from tho mam building, and the antenna is not vet erected. Also the power lino from the dynamotor is not yet laid on, but we hope to have it going in a couple of days, and then we will make a sited, and will be glad to test the portable transmitter with you.” After a little more conversation he said good-night to Now Zealand, and called a station and asked them to begin, the broadcast programme for Commander Bvrd’s party. , ‘What a wonderful boon during tho long winter nights and enforced comparative idleness must be those wirelessed programmes of tho latest songs and news! My lonely wanderings t on the border of Tibet proved to me just now lonely one can be and how long is twenty-four hours. Working station W-6xhi, an American station, whe replied to a C.Q. call from W.F.A.. he told W-6xbi: “ I guess there’s no traffic to-night, old man. Thanks for good report. _ Yes. your signals are good here to-night. Replying to a query from W-6xbi, he said; “We will not be getting mail till about February, 1980 hero, old man, -but if 1 want a ‘Q.S.L.) (an acknowledgement of having _ established com mnnication) address it care of Byrd’s Antarctic Expedition, Dunedin, N.Z. Our ‘O.R.A.’’ (address) is 700 miles north of tho South Pole, in Ross Sea. That’s 2.300 miles south of New Zealand. We are neither shin nor land station, but are on Ross Sen ice barrier. Hi! 500 watt set here; 500 cycle 73” 173 stands for “kind regards”). A little latei he calWl “C. 0.” acrairt, and worked W-fihtm. After yarning for about ten minutes he closed down transmitting to keep a schedule with someone else, and to’d 'V-Ohtm that ho now had to copy PN (Pi*ess news). j?, pr i ; er tfio evening, sneaking to N’o-v Zealand, he r-omrkod. in replv + p a fro™ Gm r f’wi • “ f i'’wn"™ nw"'* soon. fV” f-of G-o ,vo"ro+’' of t’-o ' pl-n'.-f fSo .1.1 TC 4-I. t* ~o+ IV-i- c.-* oro-V ‘M f- 1 -- "--ti ( ~’,..1-’ o--o O P >- ~'-,.,4.4.., fj-l-o+l-A o"’s now.-l fo+ol’ + t, o+ 1,„ mo r’-o-1 -o-o V„„, C. +o + IoTII (o-ll nlo-n. o-. —4-1-. V mbrnioo- on fonrfoon mof-rs. T!;->v came in (rood, a n d we w ; H he pT' l to make tests on fourteen metres when time permits.”

STRAY SPARKS. Ono American station at least is making a feature of the slumber hour, but an English paper asserts that there is nothing new about that. They had had one for a long time when the topical talkers were about. « ft * « Had it not been for radio, the land headquarters would have taken a long while to find out that the Imperial Airways air liner City of Ottawa, flying from Croydon to Paris,, had been forced to land in the Channel. Through wireless the pilot of the plane was able to keep in touch with the land until his machine touched the water, when the generators were consequently put out of action. « 9 * * ft is said that by placing the loud speaker near a heavy curtain its tone will bo considerably softened. 0 0 # * Two northern writers, reporting on reception of the official opening of the new 4YA state that ? -although there was an improvement in volume, it was not up to the strength of the Exhibition days. 0 0 % # In the matter of radio licenses Victoria holds the most licenses of any State in the world. There are at present 140,500 license-holders in Victoria, or roughly 2J times those in New Zealand. e « # # It is estimated that in 129 epuntries, irom Ethiopa with two receivers to America with nearly 10,000,000, there are over 20,000,000 receiving sets in uso to-day. • « * • With the advent of the talkies the once-popuiar comedian is going out of existence. The talkies don’t want him, and neither do the gramophone recorders or the broadcasting stations. His comic appearance is useless before the microphone or in the recording studio, and on the talkies ho is lost_ without the immediate response of his visual audience. What, then, will become of the one-time bright and popular entertainer? • » 9 • According to reports, one private broadcasting company in America spent over £1,000,000 in programmes in one year, and yet American listeners are not called upon to pay a license fee. However, the American companies depend on advertising per radio for revenue. * * » ♦ The announcer at the short-tvave station in Holland PCJ, whoever he may be. makes his announcements in English, German, Portuguese, French, Spanish, and Dutch, and is therefore understood by every white listener in the world. The question has been asked: “ What is the announcer’s nationality?” * # «■ i' After passing through 21,000 miles of .space a concert originally broadcast from Sydney reached Commander Byrd and his companions at Little America recently. 2ME Sydney put on the programme, which was received by KDKA Pittsburgh, which rebroadcast it for the benefit of the explorers.