ON THE AIR

Hawera Star, Volume XLVI, 22 January 1927, Page 18

ON THE AIR

(By “Wave Length.”)

The enterprise of the Broadcasting Company in .putting on a special concert. at Auckland recently aroused a great deal of interest and comment. The concert, was well advertised in pirint, as well as by radio, and no douot 'it had, as a wireless event, a record audience for New Zealand. It was reported by an Auckland paper that the programme cost about £25. The concert was arranged “at the request of the Secretary of the Post and Telegraph Department ... to demonstrate to listeners the type of programmes which will be regularly broadcasted when the number of licensed listeners reaches the approximate figure of 40,000. ” The preliminary announcements made regarding the special concert resulted in a great many people introducing themselves to wireless listening. In the circumstances it was most unfortunate that. the transmission was a very poor one, and about as bad an advertisement as wireless could have had. at all events in this locality. Except for short spasms in the latter part of the programme the transmission was unusually weak, and what was audible was considerably affected by faulty modulation. To make matters worse, the atmospheric and “man-made” interference was atrocious. Fading was marked. In some localities a powerline leakage which had not been heard for months broke out, and persisted nearly all through the programme; and there* was a simply phenomenal amount of ship traffic, interference, some of it of tremendous strength. Added to this the interest in the concert having brought every available set into operation, and the transmission being very weak, there was. even in a normally quiet suburb, a continual chorus of oscillating receivers. As one listeuer re“lf this is what we’re going to get regularly when there are 40,000 listeners. Lord'help ns when there are 80.000!’’

The present overcrowded broadcasting wave band is due to the fact that there are only 8S available wave channels between 210 and 546 metres, and it can be readily seen what an enormous expansion can be made when it is realised that between 10 and 100 metres there are some 2098 wave lengths that can be used, spacing, as has been the practice in the States, .10 kilocycles apart. This means that a very large increase can be made in broadcasting stations and that each station may have an individual wavelength.

Broadcasting on a short wave length, as well as the present 422.3 metres, will be a Tegular feature of the Crosley WLW 50 kilowatt. (50,000 watts) super power station in Cineinatti. Thenwill be many more stations broadcasting on short waves as the audience increases and realises the clearness of reception on the lower band. It is reported that station 2BL, Sydney, and JOAK, Japan, are testing out on short waves on about 39 metres.

One family had an interesting personal anecdote illustrating the universal appeal possessed by the Sunday services broadcast by 31.0. 'Melbourne. One of the family was prevented by sickness from the usual attendance at church, and the set was called in to supply the deficiency, when the minister officiating was heard to offer up a special prayer “for those distant listeners-in who, by sickness or infirmity, were unable to attend Divine service.’’ This was a very real ami human touch that went right home, to that- particular listener, as doubtless to m,™v others in like ease.

The services of the P.M.G. \s wireless branch have had to be requisitioned in Beechworth, Melbourne, in order to run down some persistent local “howler’’ who made a real nuisance of himself during the cricket announcements. This sort of thing at once suggests that a vigilance committee of local listenersin" > might act with more promptitude and despatch than the necessarily limited staff of the Postal Department. In Beechworth luckily the local press and other prominent townsfolk took action at once to draw the attention of the authorities to the offender, who will probably be found to have been quite ignorant of his offence, which was none the less real and irritating, and undoubtedly docs (prevent the growth of wireless in districts where such weeds flourish.

Charles W. Peterson, the well-known acoustical engineer and inventor of the widely-used Orosley Musioone, has discovered that the tone quality of the average cone speaker may be considerably improved by simply mounting it behind a hole in a board. The board, or “baffle’’ as Peterson calls it, serves to accentuate the low tones usually lost in radio reception.

Tor a baffle he uses a square board measuring about four feet on each edge, or a round board of equal diameter.' A hole is cut in the centre of this board, the size of a speaker cone. The speaker is then, mounted on the back of the baffle so that the point of its cone extends through the hole, and the whole unit is hung near a wall.

The result of this ‘arrangement is that low notes of organ music, and of orchestras or instrumental solos are brought out with surprising clarity. The tone quality is more mellow, full and pleasing than can be obtained with anv other ordinary speaker. Music sounds more natural, and static and other very high-pitched notes are reduced.

In conducting the experiments, Mr Peterson tried several cone type spetikers. While using the Musicone, which lie developed he discovered that practically The same results could be obtained by mounting it. behind a hole in the front of a console cabinet, providing that, the cabinet and hole were designed properly. This discovery is of tremendous importance from the manufacturing point of view because it makes it possible to build console type sets which give unusually good quality of reproduction.