NOTES AND COMMENTS

Radio Record, Volume I, Issue 39, 13 April 1928, Page 8

NOTES AND COMMENTS

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Professor Rogotti, of Milan, with two assistants, transported a radio receiver to the inside of the world-famous volcano Vesuvius, to test the radio-receiv-ing qualities of this somewhat sparsely populated area. ‘The tests seem to prove that radio reception is impossible near the eruptive cone of the volcano, while at a distance of 800 feet from the vone reception was rather poor, ‘I'he experimenters wore masks, as a protection against the stifling gases from the erupting cone. A new valve that has been patented by an Englishman is claimed to be tapable of acting as a radio stage, detector, and three audio amplifier stages, all combined in the one yalve, thus actually capable of giving loudspeaker strength of inter-State stations with one valve. ‘here are seven contact pins te the valve. It has been suggested that in order to discriminate valves and bases, each valve be given a colour. For instance, the detector socket may be coloured green. All detector valyes should have green bases, and it would -then be a timple matter to fit it into its own socket. | Howling in the loudspeaker may frequently be traced to the B battery, especially where more than one andio stage is used, ‘This is due to the high vesistance of the faulty battery, producing a coupling effect between the audio stages, which, in turn, creates an audio frequency beat note. Then, a microphonic valve is often the delinquent. The source of this trouble lies’ with the faulty construction of the valve elements. A micropllonic valve becomes very exasperating when regentration is over sensitive. ‘he detector yalve is usually to blame, Anti-vibra-tion valve holders help considerably, but it is usually imperative to change the valve. In the course of his speech at the Reichs Rundfunk Geselischaft’s reception held recently in Berlin, Dr. Hans Bredow, Commissioner of Broadcasting, said that with over 12 per cent. Berlin’ holds the leading position among big tities in the percentage of radio sub- | *Mribers to population, London coming next with 8 per cent., and then New York with 6 per cent. Thirteen per vent. of the total number of German. households are subscribers to broadcasting. The Commissioner also referred to the position achieved in European broadcasting by England and Ger‘many, quoting from the "RB B.C, Handbook"? for 1928. In conclusion, Dr Bredow mentioned the efforts towards world hroadcasting, which, he _ said, would be promoted by Germany’s convtrncting a great short-wave station. Ailsa Craig, the island rock at the mouth of the River Clyde; Scotland, where most of the good curling stones Jome from, is to be equipped with a ransmitter and receiver. Apart from the keepers of the lighthouse, the only other occupants are myriads of sea birds. The use of wired wireless as a means of distributing programmes over the telephone or electric light wires, instead of through the ether, appears to increasing both in Ametica and on the Continent. It offers the most practicable scheme for ensuring a choice of alternative programmes in large towns where selectivity unon a wireless receiver is rendered difficult by the $reserice of the local broadcast stawons. Several pro¢rammes are fed simultaneously into the same conducting wires on a common cartier wave. and are separated out .t the receiving end, simply by plueging in the ap. propriate filter circnit. The currents 30 received are enormousty s.ronger khan the wireless waves picked up on the outside aerial Broadcasting stations in America are endeavouring to do awav with the numerical call sign and jumble of letters, suggesting that a name would he more suitable. The argument is that if shins were identified same as hroad.tasting stations. we should need a ref: erence library if our friend told us he would he sailing for Great Britain on the 465,958.857 Certainly shine have license numbers, but they have hames also. and thev are known and recognised hy their names, New legislation in France will provide for the imposition of a new tax on receiving sets, ranging from 5 francs a vear on crvstal sets to 25 frances fot velve sets. This measure will throw an interesting sidelight on the actual humber of listeners in France. M. Bokanowski, the Minister of Posts and TelcFraphs, has placed the number at 95,544, which represents the number of receiving sets declared, whereas competent outside ohservers have estimated it at nearer half a million. This is probably the more accurate figure. A measure to tighten up the collection of the tax 1s also under consideration, As things how stand transmissions are practically limited to all the dull recital of market prices, stock exchange quotations, news, such music as has become public pro petty owing to the Japse of copyright, and lectures. France is to have a Communist broadfasting station. M. Vaillent Couteurier, tfommunist Deputy, is the donor of the jtation, which is to be known ag the Red Star,