INTERESTING JOTTINGS.

Waikato Times, Volume 101, Issue 16947, 9 November 1926, Page 10

INTERESTING JOTTINGS.

(By "Rheostat.") The most important item of interest to listeners this week is the following announcement from the Sydney Daily Telegraph. "Mr J. M. Prentice, 'Uncle .lack,' of 2BL, who has been associated wtih Broadcasters, Ltd., for the past two years, has resigned his position as announcer to accept the position as chief announcer to Radio Broadcasting Company of New Zealand. After negotiations extending over several months Mr Prentice has been engaged to organise the studio side of the four stations which the company operates at Auckland, which will be his headquarters, Christchurch, Wellington, and Duncdin, spending periodic visits at each, and training the the local announcers. In addition, Mr Prentice will act as adviser in all matters relating to programme preparation and presentation. Mr Prentice will sail from Sydney on the Aorangi on November 18." Though no official statement as to the correctness or otherwise of this announcement has been made by' the N.Z. Broadcasting Co., Ltd., there is no doubt about the genuineness of the statement, as on Sunday night the writer heard Mr Prentice speaking from 2BL. Sydney. He stated that that was probably his final appearance before the microphone in Australia, as he was sailing for New Zealand on the 18th inst. He said his work had always been a delight to him and it was with genuine regret that he was leaving those who had been so kind to him during the two years that he had been associated with Broadcasters Ltd. Though he would not be able to be with them personally he was pleased to know that when he faced tho microphone in New Zealand they would still be able to hear him, and he would feel as though he were still talking to old friends. Mr Prentice was making these remarks at the Thcosophical Society's meeting and his speech was greeted with loud applause. Mr Prentice is a fluent speaker with a perfect command of the English language and with none of the affectation that usually characterises the amateur announcer. Ho has the gift of infusing his personality into announoemtnts, giving each listener the impression, that to him alone is the announcement being made. As a teller of bed-lime stories Mr Prentice has the love of children throughout Australia and New Zealand. As an announcer he has only one equal in Australasia, viz., Mr G. Saunders, "Uncle George," also of the 2 B.L. staff.

"Uncle Jack's" breezy manner and perfect diction is known to every listener in Australia and he will be a distinct acquisition to New Zealand broadcasting. He has a wonderful knowledge of music and composers and his chatty little prefaces to the various items from various places of entertainment where he has been in charge, have greatly added to the enjoyment of the programme. It is to be hoped that when he takes charge in New Zealand that he will be given full scope for his wonderful organising ability and powers, of entertaining. With a few more men like "Uncle Jack" at the head of affairs in New Zealand broadcasting would be on, a very mueh better basis than it is at present. In the meantime good luck Uncle Jack and best wishes for your success in New Zealand. I have often wanted to shake you by the hand and congratulate you and now that you are actually coming here I hope to have the opportunity of doing so. WIRELESS IN HOSPITALS. The announcer of 2FC Farmor's Sydney stated on Saturday night that the Royal Hospital in Sydney had just been equipped with 140 pairs of headphones to enable patients to listen-in. This had been made possible by the generosity of various people in providing the equipment and by various unions doing the installing work free of charge. If such an installation couid be put in at the Waikato Hospital Rheostat feels sure it would be greatly appreciated by tho patients. If any of our wealthy residents will provide the equipment Rheostat will be only too pleased to give his assistance and to get others to do the installing work free of charge. Now who will be ihe 'first to offer to provide the equipment. About £2OO or £3OO would be required. OVERLOADING EARDRUMS. How long can signals be la the headphones before any strain is put upon the ear-drums? It is certain that a time must come when signals can bo too loud and harm, or possibly permanently injure, fhe delicate fabrication of the ear. Indeed, a case has been recently reported in which a listener suffered a "singing" or "buzzing" in the ears as a result of listening with headphones to signals that were too powerful. The set in use was designed for loudspeaker reception and tho operator changed the loud-speaker for a pair of phones. Of course, the signals were deafening—and the listener's cars were affected. Such an uncommon occurrence need occasion no alarm that anybody listening to loud phono signals will be affected in any harmful way, but it is just as well to realise that such a possibility does exist in Ihe case of those persons wiio have weak car-drums. Nobody can say just how loud signals can be before they become harmful—any such decision must perforce rest with the individual concerned. In this respect there seems to be some argument for the* inclusion in the detector-valve anode circuit ,of a set witli two or more stages of lowfrequency amplification of a pair of terminals for headphone reception. Tins allows of tuning-in on the headphones in comfort and . does not necessitate the complication of a switch to cut out the low-frequency stages. PLATE VOLTAGES. Not everyone realises that a considerable improvement . in reception may often be effected by experimenting a little witli tho plate voltage of the valves in the receiving set. if you use a common high-tension busbar for all the valves in tho set a compromise voltage which enables all lo give pretty good results must be found. Experiment will show thai though lliis is usually not' very critical there is a best point at which stability signal strength and quality are all satisfactory. Too high a voltage may lead to instability and poor rectification, .whilst if the voltage is 100 low there may be distortion in the low-frequency side of the set. Where there arc separate higli-tcn-sion positive leads for high-frequency, rectifying and low-frequency valves it is most, important lo find Ihe correct plate potential for each. On the high frequency side we must

combine sensitiveness with stability; the detector valve must rectify without distortion, and the note magnifier must give a large volume of sound combined with purity. If an hour is spent in experimenting with plate potentials is will often lead to a marked improvement in results. HUGE AUDIENCES. A recent survey made in the United States of America reveals the fact (hat there are nearly five and a quarter million radio sets in tho United States; and statistics gathered by WEAF show a potential audience of 15,000,000, each receiver being estimated to have an average of five listeners. The following arc the figures for some of the most important cities: New York, 702,000; Boston, 380,000; Philadelphia, 265,000; Washington, 166,000; Buffalo, 125,000; Pittsburgh, 208,000; Cleveland, 172,000; Detroit, 224,000; Cincinnati, 187,000; Chicago, 354,000; St. Louis, 140,000; Minneapolis, 73,000; and Davenport, 88,000; making a total of 3,090,000. Based upon these figures it is believed that there .are 5,200,000 receivers in the United States. CAUSES OF TROUBLE. (Second Instalment). Muffled Signals.—l. Defective grid leak.' 2. A battery run down. 3. Grid leak of incorrect value. 4, B battery voltage too high. 5. Grid condenser of too higli capacity. 6. Phone cord of too high capacity. 7. Defective grid condenser. 8. Damp coils. 9. Potentiometer necessary. Distortion. —1 Defective valves. 2. B battery voltage 100 high. 3. In reflex sets, catswhisker corroded or not making contact with crystal. 4. A battery run down. 5. Phone cord of too high capacity. 6. Secondary or transformer reversed. 7. C. Battery needed. 8. Valves not making contact with sockets. 9. Grid condenser of 100 high capacity. Weak Signals.—l. Defective valves. 2. Defective grid leak. 3. A battery polarity reversed. 4. B battery of too low voltage. 5. A battery run down. 0. Poor aerial or ground. 7. Valves not making contact with sockets. 8. Grid condenser of too high capacity. 9. Phone cord of too high capacity. 10. Defective phones. 11. Loose connections. 12. Poor contact on secondary condenser. 13. Inferior parts, especially condenser.

LET THE WIFE LISTEN. It is not an uncommon tiling to hear that a married man who has a receiving set frequently gets called to book by his wife for being unsociable, especially if he has the 'phones on his ears, and sits there hour after hour caring only for his own enjoyment. This trouble is easily overcome by using a loud speaker. Furthermore, teach your wife and family to tune in for, the afternoon concerts, and you will receive the blessing of the whole family spontaneously. Every man's belter-half likes to be in the joke, and every mother likes to let the children hear the music during the afternoon and early, sessions. Try it; you will be surprised how often your family will prefer to stay home rather than go to the theatre. VARYING VOLUME. Many broadcast listeners attempt to retune their receivers when one programme number gives way to another. They notice a decline in volume, and immediately assume that the set needs adjustment. If the tuning dials are not altered, the rheostats or volume control, or perhaps both, are tinkered with, on the assumption that this is necessary. In almost every case there is no occasion for touching the receiver. The volume change is entirely due to conditions at the broadcasting stations, or really the studio. Perhaps a soprano singer has just given way to a brass band. The operator in the control room of the station takes care of the volume by adjusting resistance connected with the speech amplifier (an audio channel used for regulating the amplification of everything broadcast by the station). A different adjustment is needed for a band than for a soprano singer, and it may take a minute or so before the transmitter can be properly adjusted to suit the new conditions. Therefore, when a station seems to be suffering from an odd form of fading at the commencement of any new item, keep in mind the probable cause, and let your receiver alone. No attempt should be made at readjustment until a few minutes have elapsed. It is also wise to remember that when a church service is being broadcast, that the conductor of the service is often speaking to his congregation from various parts of the church, and that is is often very difficult for the engineer in charge of the amplifier to get just the right adjustment necessary for good transmission. NEW WELLINGTON STATION. Wellington listeners have been severely criticising their broadcasting station lately—partly as the result of comparison with the new transmitters at Auckland and Christchurch, and partly because it has fallen from grace lately, states a Wellington wr;tei. There is a rumour that a new station is to be opened shortly, but how long "shortly" means is a question. The writer ("Grid Bias") has been provided, as the result of an inquiry, with the following official statement from the head of the Post and Telegraph Department:— "The agreement between the Post-master-General and the New Zealand Broadcasting Company provides for the erection of a broadcasting station at Wellington by the Broadcasts Company when called upon by the Postmaster-General. The Fostma>terGcneral has intimated to the Bvoadoasting Company that a station should bo proceeded with, and negotiations arc now in train with a view to the establishment of a suitable station within the next nine or twelve month* The Post and Telegraph Department has no information as lo whether a definite order has been given for the •erection of the station. Such information could only be given b> the Broadcasting Company." 2FC Farmers Sydney put on a novel stunt on Saturday night. A small broadcasting plant was installed on a trawler and an announcer was sent out lo describe his experiences. These were picked up by wireless and revived by land line to the broadcasting station and re-broadcast. The aolua broadcasting arrangements worked oxcellentlv, and the announcer on the trawler was heard perfectly. The trawler however, was unfortunate enough' lo get its trawl caught in the ro cUs and to lose ils trawl consequently the announcer could not describe the fish caught. Evidently hewas not having 100 good a time on the boat because he said: "I don't mind an aeroplane but a trawler does some funny things." The laughter of the crew whicli this statement evoked, was clearly audible, and it was very evident they were keenly enjoying Ihe

discomfiture of the land lubber. As a result of the accident the experiment lost much of its interest but at the same time the transmission was eminently satisfactory from a technical point of view. In the near future, perhaps, we may hear motorists describing their transit through the ilood waters at Mercer, or a factory manager telling us how butter is made, while the work is in progress.