LISTENING IN

Waihi Daily Telegraph, Volume XXX, Issue 8495, 29 July 1933, Page 2

LISTENING IN

GROWTH of wireless about waihi

OVER 150 SETS IN USE

USEFUL HINTS TO OWNERS

(Contributed)

The subject of wireless receiving

cannot fail to be of interest to users

of radio sets and as there are so many Waihi listeners a brief review of the various phases of radio will no doubt appeal to many of our readers. The records at the Waihi post office—obtained through the courtesy of the postmaster, Mr A. E. Lawson—show

the number of current licenses to bo 151, not including those issued in Waikino and Waitekauri, but inclusive of Athenree and Whangamata. The records also show that there are 1100 householders in the area and this means that we have approximately a radio to every seven householders.

One of the aims of the Waihi Radio Society, which lias now been in existence for twelve months, is to encourage listeners-iu to devise ways and means of eliminating noise and local interference, of which the Waihi township has more than its share. Last year the society’s remits to the Broadcasting Board boro fruit as some of them were adopted, no doubt as the result of the coordination of a number of other New Zealand clubs submitting similar remits. INCREASED POWER With the advent of the pentode power tube ,the six-pin radio valves, the universal adoption of the superheterodyne circuit and last, but not least, automatic volume control, tho radio set has increased greatly in sensitivity (power) and selectivity (separation of stations). Tone is tho one feature that has not yet been improved upon appreciably. The pentode valve used in practically every modern power stage does not compare in fidelity (true reproduction) with the older type of power valve, although it has the advantage of much greater amplification. The distortion, however, in the new pentode valves, although much greater in meter measurement, is not objectionable to the comparatively insensitive human ear. The superheterodyne radio had, until the recent development of the new valves, been uncomfortably susceptible to background noises and was notorious as a noise creator. To-day, the good superheterodyne compares favourably for quiet operation with the more or less obsolete T.R.F. (tuned radio frequency) sets and has a great advantage in selectivity and sensitivity. VOLUME CONTROL

Automatic volume control is probably the best of the latest improvements. This device, although taking away a considerable amount of sensitivity from the radio, makes it possible for one to sit down and enjoy a programme without the continual adjustment of the volume control to counteract fading: in short, it makes fading quite an untroublesome matter. Should the signal, however, fde below the sensitivity degree of the set the signal then naturally will fall, the set having no reserve. The New Zealand manufacturers are continually taking full advantage of the enormous amplification of the new 6-pin valves and this year’s models are well up to the mark. Unlike the American type they work on absolutely maximum gain per valve. This introduces a certain amount of instability and roughness of the volume control and it is purely a matter of opinion whether the extra sensitivity is worth a little roughness on the volume control.

Conditions in America are quite different to those in New Zealand, The daylight reception there more than compares with our night-time reception, consequently the demand for maximum gain per valve is not adopted by American designers, as under their conditions gentle and smooth tuning is a more important factor than the extra gain. The American invention of a valve no bigger than a torch bulb must surely change design a little in the course of a year or two.