OVER THE AERIAL.

Auckland Star, Volume LVIII, Issue 99, 29 April 1927, Page 13

OVER THE AERIAL.

WHAT WAS IT?

WIRELESS NEWS FROM FAR AND NEAR.

IYA is being heard afar. A writer from mid-Canada communicates with the local station recording excellent reception of it, and particularly commending the quality of the announcing.

Accounts of football matches at Eden Park are to be broadcast this winter, but preparations are not yet complete, so that there will be no running radio comment on Saturday's games. Many complaints are being voiccd over the plethora of piano solos on the local programmes. Four of these in one evening is surely much more than even the enthusiast for the piano would expect. Last week was published a letter from New South Wales in which the writer referred to a vocal item rendered by "Miss Dutton." The performer was Miss Thelma Duflin. Distance is probably accountable for the correspondent's slight mistake. Iu the writer's opinion there is nothing more enjoyable to be picked up in the shape of musical entertainment than that relayed from our Town Hall when the municipal band performs. Last Sunday night's programme, in particular, was a treat that must have appealed to all tastes. Several in New Zealand who have picked up JOAK, tlie humorouslylettered Japanese station, will be interested to hear that a new ten thousand watt station is in course of erection in Tokyo. Japan at present has over 300,000 listeners, over 80 per cent of them using crystal sets. On Thursday evening next there will be a slight departure from the usual form of the "foreign affairs talks" from I\A. On this occasion listeners will be invited to send in questions on any aspect of foreign affairs on which they desire information, and these questions, together with answers to them, will be broadcast. Mr. Jack Lumsdaine, already known to many listeners through his enjoyable contributions to the programmes of 2FC, will be heard in his specialties at the piano from IYA on May 12. As a humorist who writes and composes most of his songs, Mr. Lumsdaine is well known in Australia. After his first appearance at the local station Mr. Lumsdaine will on later occasions be heard in relays from the Majestic Theatre.

Business people in many quarters of New Zealand must have visioned a stupendous boom in the radio trade. Something of a boom there has been, and will be, for years, but nothing to justify the astounding rush that has occurred to enter the wireless business. Last year over 1400 radio dealers were licensed in the Dominion, which at present boasts only about 20,000 licensed sets. There must be many disappointed ones among this vast army of dealers; or perhaps thev are still anticipating the boom.

The broadcasting of the Anzac Day service was an effort to the credit of IYA. Mr. Prentice tackled a difficult task in describing the scene at the cenotaph, and carried it out well. Speeches, prayers and singing were received excellently, but the organ was again a disappointment. Many people who listened outside the Town Hall to a loud speaker reproduction of the service within were inclined to criticise the broadcasting station as a result. This amplifier, in fact, was an entirely separate affair, quite unconnected with the microphone used for the IYA relay.

The P. and T. Department has notified that the Christchureh wave length has been raised to 405 metres, only 15 short of that of IYA. The Department has given no reasons for this alteration, though it is presumed they must have some. There are hundreds in Auckland, however, who could supply excellent reasons for a change in the opposite direction, and they will remain far from satisfied until there is a radical readjustment that will enable them to tune in, without interference, a programme fiom the southern city. At present the Christcliurch transmissions are barred by proximity of IYA to the great majority who possess valve sets.

ADELAIDE IN DAYLIGHT. Mr. W. Leather adds further interest to last week's correspondence on the reception of the new South Australian station. "Re the station heard by Mr. Fenton, I would like to say that on Good Friday morning I was 'fishing,' and tuned in the station he mentions, SGK (or CK), Adelaide. We had him from 10.20 to 11.45 approximately. I am still wondering if it was a hoax of some kind, because it came in as strongly as IZB (for comparison), and I cannot get SCL as strong as that. It was a good loudspeaker strength. I make his wavelength about 250 metres, as I get IZB on 24 dial reading, and I got this on 20 on my dials. For daylight reception it is unusual, to say the least." HOW IT IS DONE IN AMERICA. . Recently in New York it was arranged to broadcast for the first time the famous operatic tenor, Martinelli. The fee for such an artist would be a staggering one, but it has to be remembered that his items were put on the air by no less tiian nineteen stations, and the call signs of these, published in the announcement, would delight the eye of a cross-word puzzle fiend. ALONE AND FORGOTTEN. Often urgent messages are broadcast for relatives and friends who are in distant and sometimes unknown parts. Many reunions are brought about—alas! in some cases, at the death-bed. Only a few days ago an aged woman was dying, alone and, she thought, forgotten. She called for her son, whom she had not seen for more than twenty years, and who was supposed to be somewhere in Tasmania. 3LO, Melbourne, sent an urgent message out on the ether. This was picked up by a little girl near Stanley, in Tasmania, who knew the man so eagerly sought. She immediately had the message communicated to hit", with the result that the last moments of the old ladv'a life were spent in contentment with her son. Strange to say, he had lo6t trace of his mother, she having, like himself, drifted from place to place during their long separation. The tragedies and romances of life are brought home to many people by these urgent messages. "Truth is stranger than fiction," and some day, perhaps, a listener-in may be inspired by tbem to run into print with a successful true-to-life 6tory.

(By "PHONOS.")

RESISTANCE COUPLED AMPLIFICATION. W here a crystal receiver is used for the reception of broadcast music and the same purity of reproduction is desired the best type of audio frequency amplification that can be used is resistance coupled. It will be noticed that the music coming from the average radio receiver is easily distinguishable. The transmitting devices in the broadcast studio reproduce perfectly and send out through the ether the music exactly as it is played in the studio. These broadcast waves come in on the receiving aerial and are "detected" bv the detector. With a crystal detector nothing will happen at this point to distort the signals. It will thus be seen that if distortion occurs when a crystal receiver with an amplifier is used that this distortion must take place in the amplifier. It is this distortion that makes radio music so distinguishable. This is due to imperfect audio amplification, "lost tones." It is interesting to note that years ago when wireless engineers were making experiments to improve the reception of Morse code they discovered the method of Resistance coupled amplifica- j tion. This method brought signals in clear and sharp, but with the growing demand for more and more distance — and with it more and more volume—this method was dropped without being developed or refined, and the transformer coupled system was adopted. The only thing that transformers had to recommend thein then was more volume. The question of distortion meant nothing, as it did not matter to the dot and dash listener. A dot was a dot and a dash was a dash, and the sound of the note did not matter in the slightest. It was only when broadcasting became popular and of general utility that the experiments were carried out to give amplification without distortion and the method of resistance coupling was again resurrected, improved and brought to its present-day pitch of perfection. Resistance coupled amplification can bo added to any set, but it is particularly to be recommended for use with a crystal detector. A crystal detector will not of its own accord distort in any way incoming signals, and if the owner of the set desires greater volume with the same undistorted reproduction, then this is undoubtedly the best method of amplification to use.

The best type of valves to use with resistance coupling are those having a high impedence value. Practically all valve manufacturers make a type of valve specially suitable for this purpose, and it will be found that they are a big improvement over the ordinary valves when used in this type of amplifier. THE CHOICE OF A RECEIVER. For those who contemplate the purchase or the construction of a receiver there is the question "What kind of a receiver do I need." The answer is governed by many factors, the chief among these being the location in which the set is to be used. If it is to be used in the country, anything less than a four-valve receiver will not give good consistent reception. For local work, up to a few miles from the station, a crystal receiver will give good earphone results, and should a speaker be desired it can be made use of in conjunction with a crystal and valve amplifier. It must be clearly understood, however, that the addition of a valve audio amplifier to a crystal will not increase its range—only the volume it will produce. To make this quite clear: If a station cannot be picked up on the crystal, the audio amplifier will not help one bit. As long as the station can be heard on a crystal receiver the audio amplifier will magnify the sounds to sufficient proportions to allow a speaker to bo worked. For medium distances a three-valve receiver can be made good use of.

It is as well when buying a receiver of this type to have a radio frequencv valve, a detector, and one audio valve. The radio frequency valve increases the pick-up range of the receiver, and should be included rather than a detector and two audio stages. Another valve is not so easily added to the detector and two steps, while the addition of an additional audio valve to a radio detector and one audio completes a standard four-valve receiver.

The amount of volume required will, of course, enter into the points of deciding the type of receiver needed for any particular circumstancc. If nothing moro than ear phone reception close to the broadcast station is required I would advise nothing but a good crystal set. If ear phone reception is desired at distances greater than, say, 50 miles, a two-valve receiver may be employed. For loud speaker work at any distance the safest investment is a four-valve receiver. Five-valves have their use for the picking up at full loud-speaker strength of distant stations. This same applies to super heterodyne, and the many types of multi-valve receivers.

Perhaps the most important factor in the choice of a receiver is the price. But, as in the case of most good things, price is not everything. Always buy the best; it will pay in the end. One may buy a piano for a few pounds; others pay hundreds, and it is usually found that the dearer instrument is the better bargain. The same applies to a wireless receiver.

"W.A. Crystal" writes thus of an I interesting reception:—Just before retiring on Monday evening (Anzac Day), at about 11 o'clock, I put on mv headphones and heard the following oil a crystal set, loud and clear: "Form fours, right, quick march." followed by band music, and then what seemed to be a clock striking the hour. Next followed the blowing of trumpets, followed again by band music, then the clock striking. I heard the striking as of a clock, three or four times, and the last time I heard it I counted eight. What I heard next sounded like the playing of an organ, and then faded away. I heard no station calling, and I failed to get any more signals up to midnight, when I retired. The whole lasted about 15 minutes. I may add that on clear calm evenings 1 have picked up 2BL Sydney, fairly strong on the same set, and have heard the G.P.O. clock chime and strike the hour of nine. Perhaps some listener-in could explain the above.

The writer was listening-in to several Australian stations on Monday night, but cannot recall any item in which the remarks quoted above occurred, but as there were, during the evening, several items descriptive of Gallipoli, it is probable that the writer picked up part of one of these. One in particular, "A Oallipoli Incident," broadcast from 2tC, was a most realistic reproduction of a pathetic dialogue in a listening post on the peninsula. So vivid was it, indeed, that it proved too much for at least one New Zealander who had been through the horrors of the landing.