RADIO NOTES

Rotorua Morning Post, Volume 1, Issue 31, 29 September 1931, Page 5

RADIO NOTES

"Kathode."

By '

Mr. Walter Brough, the popular Auckland haritohe, who is now a resident of Wellington, will be heard from 2YA this evening. He will sing "A King's Man," "I Did Not Know," "Harlequin" and "That's All." Miss Nora Green, contralto, will be heard in "Flight of Ageg," "Colway by the Sea," "An Old Garden" and "Ma Curly Headed Baby." Mrsr Billy Hart will contribute popular songs at the piano, and Berthold and Bent, a j popular guitar duo, will he heard in late nnmhers. Incidental music will be supplied by the Salon Orchestra. "A Night with the Scots" is the type of entertainmeUt from 4YA this evening. The Dunedin Highland Pipe Band will play some bf the traditional music of Scotland, ineluding Highland dances. Miss Eva Judd will be heard in several violin numbers, and Mr. W. B. McEwan, Dunedin's Public Librarian, will give a fifteen minutes talk on "The Love Song of Burns." " " An International recorded programme will he broadcast from 1YA this evening. I The New Zealand stations continue to he received with exeellent volume and dpring the past week the Australian stations have been* above the average strength. "Kathode" has been able to tune in 2FC, 2BL and the Ameriean station KFI shortly after 5 p.m., during the paSt few days. The latter station should be received well now that winter is near in ■ the U.S.A. : A radio frequency choke is an essential component in a radio set and construeters are often at a loss to know the best type to pnrchase or construct. A r.f. choke is usually thought of as a coil of wire having a certain inductance and distributed capacity. The latter is a troublesome characteristic in all chokes to a greater or less degree, though minimised 'cdnsiderably in the slot wound type. In bnilding a choke, see that the slots contain different numbers of turns. This method of construction overcomes to a certain extent the peaking or resonant points and tends to minimise distributed' capacity.

The enjoyment of a radio programme depends greatly npon the mental and physical attitude of the listener. For instance, one might hardly be expected to enjoy a radio concert when suffering from toothache or on learning that an exti'a 10 per cent. reduction is to be made on his salary. Light, too, has a great effect upon the listener. Bright lights are irritating and tend to detract from real enjoyment. Have you ever noticed how irritating it is to sit and watch an entertainment, before the theatre lights are dimmed? Too much volume is another thing to avoid. The concert should be only faintly heard two rooms away. To hear the best tone from a receiver one should sit-as nearly as possible in front of the loudspeaker, as a dynamic throws the sound out in conical formation. Constructors should avoid placing shields too close to a coil. By doing so, losses will be introduced. Steel shielding in particular should be kept separated from the radio frequency transformers a distance at least equal to the diameter of the coil. In building a short wave receiver, steel shielding is best, as ferrous metals prevent a.c. hum from penetrating them, whereas metals such as aluminium do not completely shield out low frequencies. An earthquake in New Zealand — another in Nicaragua — Sealer Viking explodes off Newfoundland coast — a motor ship in open sea sends a 40metre S.O.S. and everywhere streaming headlines blacken newspapers with news sent by radio transmitters. Yes; we live in a wonderful age and radio has been to the fore in aiding mankind. Time and distance have been annihilated and if radio were suddenly cut off it would seem as if the world was plunged back into dark

ages. Kathode is experimenting with a.c. pentode tubes and hopes to be able to give constructors some useful data relating to them in the. near future. These tubes require speeial circuits and so far results are encouraging, though it is doubtful whether one pentode is as efficient as push-pull using super power valves.