THE COMING WEEK.

New Zealand Herald, Volume LXVI, Issue 20364, 19 September 1929, Page 18

THE COMING WEEK.

A WAR-TIME EVENING. • Tho following is an outline of the pro- i grammes from station IY.\, Auckland, i next week: — Sunday.—Evening service frotn the Pitt Street. Methodist Church, preacher tho Rev. W. Walker; studio concert. Monday.—Relay of debate at .Auckland University College. Tuesday.—Operatic and musical comedy programme; review of new grUmoplioii'j records. Wednesday.—The New Zealand Four; Mr. G. A. Fowler, violinist. Thursday.—Novelty programme, "Not Quito on the Western Front"; gramophone dance programme. Friday.—Relay of concert from Lewis Eady Hall; Madame Mary Towsey's Quartette: pianoforte numbers; instiumental trio, Saturday.—Rebroadcast description of inter-island Rugby match at Wellington; tho Askwiths, the Bohemian Duo; Jngall's Huwaiians, studio orchestra; gramophone dance programme. / Sunday.—Relay of Beresford Street Congregational Sunday School anniversary ftoivices; studio concert. \ classical programme, mainly by modern composers, will bo given at 2YA, Wellington, on Monday. Friday ivill bo devoted to opera. A concert by tho Tiniaru Orchestral Society will be relayed to 3YA, Christrhurcb, on Monday. Sullivan's cantata " Tho Golden Legend," by tho Royal Christ church Musical Society, will be broadcast on Wednesday. The Dunedin Orphans' Club Christy Minstrels will provido a special proprogramme at 4YA, Dunedin, on Wednesday. TEMPORARY AERIALS. ,'H IN T S FOR THE MOTORIST. ' Although portablo loop-aerial sets are never likely to have a voguo in New Zealand until tho country attains to superpower broadcasting stations, there is still a good deal of scope for larger " transportable " sets, designed for uso with a tem- / porary aerial and earth. For that matter any battery-operated set of a compact type may be taken on a motor excursion or ramping trip, provided the valves are mounted to withstand shakes and small knocks, and suitable batteries arc carried. A specially-mado transportable set of the ' English variety usually incorporates receiver, batteries and cone speaker in one , fair-sized case. Tho most popular temporary aerial for outdoor uso is a length of insulated wire thrown over tho branch of a tree. It is ono of tho simplest and easiest to erect, as a tree with a convenient, branch is not fit all difficult to find in most parts of the countryside. For tho tree-supported aerial a length, of insulated wiro is needed—3oft. to 50ft. is enough for general use, as it takes up less room than the full length of 100 ft., and makes quite an efficient aerial. Rubber-covered flex is often recommended for a temporary aerial, as tho covering insulates the wire from the branches of fhe tree, thus dispensing with insulators. However, this kind of wire is bulky and .heavy, and it is preferable to use a length of No. 26 or No. 24-gauge enamelled wire, joined at the free end to a six-foot length of rubber-covered flex. The end of this is securely fastened to an ordinary wire reel big enough to hold all the wire. When unwound the reel forms a conTenient missile for throwing the end ot the wiro over the branch of a tree, especially if the reel is weighted with a few pieces of lead. Once over the branch, the wiro is so arranged that only the piece of nibber-covered flex touches tho tree. The earth connection will be the same whatever form the aerial wire may take, and the easiest system to set up is a length of insulated wire merely laid along tho ground underneath tho aerial, forming a kind of counterpoise earth. This gives very satisfactory results provided the earth wiro is not shorter than the aerial. " A contact which is less bulky for transport is an earth-spike. Tho handiest is a pieco of thin copper or brass rod, even u brass stair-rod will do, about 15in. long. -A short lead is soldered to ono end, and for easy insertion in and withdrawal from the ground a terminal head should be soldered to the top, the' other end of the rod being sharpened. A more efficient earth connection is obtained by using threo of theso rods, all joined to the earth wire so that they can be put in tho ground about 2tt. or 3ft. apart. This gives a larger area of contact with tho ground. If there aro no trees on which to erect a:) aerial, an interesting field of experiment is open in earth-roccplion. iliis Consists of two earth contacts spaced some 30ft. to 40ft. apart, connected by wires to the receiver, and dispensing entirely with an elevated wire. Signals are picked up from the " earth " waves, and a careful choice of position often results in very good reception. Two sets of earth spikes of the type described above are needed, together with some 40ftor 50ft. of insulated wire, ordinary 24 or 22 D.C.C. will do. This system of reception is markedly directional, and it is necessary for tho , earth contacts to be set out so that a ' lino joining them points toward the station to be received. An aperiodic-coupled aerial coil gives results as the damping of tho " aerial " system is thereby reduced. A kito aerial, consisting of 100 ft. of No. 20 enamelled wire attached to tho kitestring, which should be 200 ft. or 30011. Jong, gives remarkable results, especially on high ground. However, a largo kite i<4 necessary, arid theso arc practical drawbacks which will probably deter most people from using tho method except by ■way of experiment. The aerial should be' anchored to an insulator a few fecu from tho set. { . OI)I>S AND ENDS. Remember that the grid bias should vary according to tho 11. 1. being used. A filter output circuit for tho telephoneswill often improve short-wavo reception. Do riot attempt to use low high-tension voltages if you wish to get the best quality results. 'One advantago of square wire for setliiiilding is that it offers a larger'surface lor screw-down connections. A reduction of the filament voltage on Hie detector valve of a short-wave set will often help to cure threshold howl. . A great many failures to get. good re- . pioductioii ariso from carelessness with tho grid-bias battery or its leads. Never place wires or metal near a tuning toil unnecessarily, as quito serious losses can be introduced in this manner. For short-wave reception the grid-leak \aluc, is quite critical, the best resistance generally being somewhere between 4 and j {'. megohms. If you aro arranging for dance music do not forget that a. room full of people takes 'ln lot more volume to fill than the corresponding empty room. When loud-speakers nio arranged in ' series with one another it is very easy to I abort ono of them by means of an ordinary ou-off filament switch. '