OVER THE AERIAL.

Auckland Star, Volume LVIII, Issue 47, 25 February 1927, Page 13

OVER THE AERIAL.

WIRELESS NEWS FROM FAR AND NEAR

(By -PHONOS.")

On t-unday evening from IYA there will be given a short lecture-recital on Handel. The item has been arranged by Mr. A. Fairburn, of the Choral Society. The Royal fishing camp at Tokaanu is equipped with a receiving apparatus, and on Tuesday and Wednesday evenings oi next week it is expected that the Ducal party will be listening in to Auckland programmes. Naturally all will be interested to hear what will be put over for Royal ears. There is now just a clear month before licensees will be called upon to renew for 1!>27. Though there are some who pessimistically declare they will not pay another 3*V, it is confidently anticipated that April next will see the -2O.ihV> mark passed in licon>f issue*. A big radio exhibition is at present in full swing in Sydney. As these notes arc being written a concert provided by 2BL at the exhibition is being broadcasted, and those with demonstration sets working in the show have just been requested to shut oft" all loud speakers so that relav transmission will not be interfered with.

On March 20 there will be another lecture-recital, which will feature Miss Eileeu Mack, the vocalist, who came through so well from ChrUtchurch on the occasion of the first Sunday programme from the new southern station.

The main building of the Auckland Hospital is at present being wired for radio reception. From the receiving set wires will be run to the ward bed»._ and by plugging in for earphones, patients will be able to enjoy afternoon broadcasts. The use of loud speakers in .1 hospital ward would not be practicable.

On Sunday, March 6. Dr. Wilmington Tngram, Bishop of London, will speak in the Auckland Town Hall, and his address will be relayed by IYA. The evening service at St. Mary's, where his Lordship will preach, will also be put on the air. Tlie opportunity to hear the famous divine will be welcomed by many, particularly in the country. A Lecture Series. Last week Mr. Prentice delivered the first of his lectures on "Great Love Stories." when he talked interestingly on Napoleon and Josephine. It was the delivery of these stories, by the way. that first brought J.M.P. into broadcasting. He undertook to give six of them for 2BL. and well before the series was finished he was booked on the permanent staff of the station. He will shortly resume his talks on current foreign affairs, delivering an address weekly from the station at which he happens to be located for the time. For the purpose of describing the Royal visit at the other centres Mr. Prentice will go south next week, returning before the end ><l the month. THE ESSENTIA... OF AN AERIAL SYSTEM. Recently, rrom r.LO, Mr. H. K. Love broadcasted several informative lccturettes to listeners. One of these, sum marised below, will be of interest and benetit to many who cannot tune in the Melbourne station: —

'•The problem of 'What kind of an aerial will I need?' confronts every newcomer into the army of listeners. It is often stated that nothing very much is required, as it is only for a crystal set. This is a mistaken idea —a crystal receiver, to do its job properly, requires a good aerial system. A crystal receiver employs no amplifier before the detector —in other words, no radio frequency amplifier—therefore the detector can onlv use the signals which are actually caught on the aerial. It is evident, then, that the stronger the radio frequency energy picked'up by the aeiial, the stronger will be the resultant rectified signal in the telephones. I have proved by actual experience that a high aerial of big area picks up more energy than is picked up by a small one. While this fact is perhaps not so important with a valve receiver employing radio frequency amplifiers, it is of the utmost importance to a crystal receiver. A year or so ago I had installed at my own station one aerial 105 feet high, and an other 23 feet high. The 105-leet aeria : was a six-wire cage, about nine inches in diameter, and consisting of six wires The small aerial was a single wire affair. Tests made on a crystal receiver proved that the signals from a given station I were at least three times louder when received on the big aerial as those received on ihj small one. When using a single valve receiver on these two aerials, it was found that the larger aerial was at least as good as an additional stage of radio frequency amplifi cation. In fact, stations that could not be picked up with the small aerial were received at good head-phone strength with the high aerial. It is often argued that a large aerial makes tuning flat. This should be overcome by making the circuit which is coupled to the aerial circuit of a design which will compensate for any flatness of tuning occasioned by a large aerial.

TUESDAY MORNING'S SUCCESS.

Though the great body of Aucklanders preferred to witness the arrival of the Keuown. rather than to hoar it described, the achievement oi our local station in Fending out such a \ivid description of an important event was fully appreciated farther afield. From as distant a spot a> Hanmer. in the South Island, came telegrams in gratitude and congratulation. From there to the far north the account was picked up with absolute clarity, one country listener wiring that ho could even bear the clicking of the cameras on the ferry boat from which the description was sent. Mr. Prentice, who himself handled x\y account, w.is in quite pood form, and demonstrated to what extent a skilled announcer cm make vivid t'.se scene he describes. He £ot a touch of humour e\en out of the depressing rain squall that drove him to cover off North Head. The story of the procession up Queen Street, which \va« relayed from the roof garden of the .T.C.I-, building, was nl-o well heard in the country, where there was general ri'cret that tho speeches at the Town Hall were not transmitted. Unfortunately for IYA. permi-Mon to broadcast (his official function was not forthcoming, i

Tuesday , .* effort, the first of its kind in New Zealand, marked another step in Dominion broadcast in?, and a &tep that will bring it much popularity with country residents. The fact that the daylight transmission was heard distinctly over an air line of more than ."•00 miles, speaks well for the efficiency of our station. Several correspondeutin the South Island wrote stating that they followed the description* of the doings in Auckland harbour while they sat at breakfast.

POWER VALVES IMPROVE RECEPTION. Krroncou.*ly, the majority of listeners are under the impression that the power valves so often recommended for use in receiving sets really produce "power." This is not really the case. Most of the receiving sets in use to-day are capable of delivering quite an amount of volume to the last audio valve. The result Is that the usual class of amplifying valve is unable to handle the volume delivered without distortion. It was to overcome this defect that tlie power valve was developed. thereby permitting the volume to be efficiently handled, and in turn passed ou to the loud speaker.

The characteristics of these values are naturally quite different from those of the usual type. Being designed for use ■with bigher plate voltages, they also D6e higher "C" voltage as grid bia* Used as directed by the manufacturer* a set will cive greater pleasure, and the loud speaker will he given much greater opponunity to shew it* qualities.