Over The :AERIAL:

Waikato Times, Volume 113, Issue 18926, 21 April 1933, Page 8

Over The :AERIAL:

BY RHEOSTAT

THE COMING WEEK.

Sunday —lYA: 7, service from Baptist Tabernacle; 8, Municipal Band concert at Albert Park. 2YA—7, service from Trinity Methodist Church; 8.15, gramophone recital, “Shakespeare in Music.” 3YA— 6.30, service from Knox Presbyterian Church; 8.15, studio concert, “Shakespeare Day.” Monday— lYA: 11, talk, “All About Pets”; 11.30, description of Avondale Jockey Club’s meeting, second day; 3.15, home science talk; 7.30, agricultural talk; 8, studio concert. 2YA: Talks: 11.30 “Health Hints or First Aid,” 3.15 home science, 7.40 “Books, Grave and Gay”; 8, studio concert; 10, dance music. 3YA—II, talk; 3.15, home science talk; 7.35, W.E.A. session; 8, concert by Woolston Brass Band. Tuesday —lYA: 11, relay from Town Hall of Anzac Day services; 7.30, book review; 8, studio concert. 2YA—II, children’s memorial service at Cenotaph; 2.30, memorial service at Town Hall; 8, commemoration concert arra,\ged by Returned Soldiers’ Association. 3YA —2.30, relay of citizens’ memorial service; 7, relay from Anglican Cathedral of Anzac service; 8, Anzac Day memorial concert. Wednesday IYA: 11. talk, “Women's Interests"; 7.30, W.E.A. session; 8, studio concert; 9.30, dance music. 2YA—11.30, talk, “Hollywood Affairs”; 7.30, music lovers’ competition; 8, programme of recordings. 3YA —11, talk; 2, educational session; 7.30, Addington stock r.,arket reports; 7.40, talk, “Farm Pests"; 8, relay of concert from 4YA, Dunedin. Thursday —lYA: 11, talk, “Eleotrical Apparatus"; 12.30, service from St. Matthew’s Church; 3.15, home science talk; 7.30, NV.E.A. session; 8 studio concert. 2YA—3.15, home science talk; 7.30, W.E.A. session; 8, concert by Band of First Battalion, Wellington. Regimen!*. 3YA —Talks', 11 “Hints on First Aid," 3.15 home science, 7.35, Music Lovers’ competition ; 8, studio concert of modern and old-time music. Friday —lYA: 7.30, sports talk; 8, studio concert. 2YA —Talk, “For the Home Garden”; 8, studio concert; 9.30, dance music. 3YiA —11, talk, “Feeding the Family": 7.35, W.E.A. session; 8, studio concert. Saturday —lYA: 2. >5, Rugby at Eden Park; 7.30, horticultural talk; 8, studio concert; 10, sports summary; 10.10, dance music. 2YA—--4.30, sports results; 8, studio concert; 10, sports summary; 10.10, dance music. 3YA —8, relay from St. James Theatre of “A Runaway Girl,” by the Christchurch Amateur Operatic Society; 10 (approx.), sports summary; 10.10, dance music. AUDIO SELECTIVITY. PROBLEM OF TOP NOTES. If you take a circuit and equip it with tuning coils, each having a low damping factor, you cam obtain a good measure of selectivity; and, provided you have the means at your disposal to use a sufficient number of such circuits, there is no reason why the tuning curve should not be perfectly flat, say, 9 kilocycles on either side of the tuning point, with a steep drop to zero response 11 kilocycles off tune. Given these ideal conditions, says a writer in an English journal, there would be little need for us to get worried over the question of interference or the inherent “snags” of selectivity; but unfortunately the Ideal does not exist in practical radio insofar as the “man in the street" is concerned. What are these difficulties which selectivity brings with it? In order Go explain matters as sirhply as possible, suppose we consider the tuning circuit of the ordinary straight S.G. “three." We have first of all a tuned aerial circuit which may or may not be band-passed. Next we have a tdned detector grid circuit which probably consists of a solenoid coil with reaction supplied by means of a small condenser and a winding coupled to the grid coil. In a good design these tuned circuits will be reasonably low-loss, and any damping in the detector grid coil can easily be wiped out by the use of reaction. With care we can achFeve the degree of selectivity we need, but not even band-passing will enable us to obtain the perfect tuning curve; and so, although the station-separating powers are there, some cutting of side-bands, with its resultant reduction in high-note amplification, must exist. Now this falling off of those notes ; which give music its tonal brMliaacy and speech a crisp and life-like ! enunciation is solely dependent upon ; the type and number of tuning cir- ; cuils "that are employed. Reaction improves selectivity, but ■ aggravates the loss of treble and top ! note's. The loud-speaker may even—- ! put. not necessarily—accentuate the I trouble. ITEMS OF INTEREST. The value of all the individual wirelßss sets in the world is reported ]at £200,000,000. About £30,000,000 iis spent every year throughout the i world is actual broadcasting. . There are 140,000,000 people in the world to listen in on the wireless, according to figures announced at j file Radio and Telegraphy Congress iat its meeting at Madrid. The statis—- ; tics have been compiled by the lnterI national Broadcasting Union, of which j Vice-Admiral Sir Charles Uarpendalc ■ is president. When one looks through the programmes broadcast from the Aus--1 Indian stations there is a wish that I New Zealand stations’ would put over la few programmes of a like kind and j quality. if we had "The Mikado," ‘iolanllie’’ and “La Boheme” all in one week or one year we would lie very satisfied, but week after week Australian listeners get programmes with opera's, plays, etc., such as these, j Soon our winter will be here, and j “Aussie" stations will be roaring in. and sitting beside a nice lire in comfort we will hear these Australian stations on such programmes—gratis.