RADIO NOTES

Rotorua Morning Post, Volume 1, Issue 97, 15 December 1931, Page 2

RADIO NOTES

"Zathode."

By

Messrs. H. G. Smith and-D. W. Tapp were nominated by the Rotorua Radio Club as candidates for the Radio Advisory ; Council, soon to. be appointed by the Postmaster-Gen-eral. Though the candidates appointed will not be in a position to dictate any policy, they will be able to place the listeners' views before the Radio Board, and as the listeners will provide the necessary capital, the policy will he influenced to a - great extent by their representatives on the council. The Rotorua Radio Club has done , excellent work, and most of its objects have been obtained. When the j| club was first formed, radio was more " or less in a developmental stage, and ( the club did much to advance the | science. The day of experimental | radio has almost passed as far as the > listener is coneerned. The A'.C. re- | ceiver has advanced to such a stage f that a professional is required for its construction and repair. The average listener now pur'chases a receiver and is little interested in the science of radio. The constructer and experimenter of yesterday has either given up his hobby or joined the professional ranks. To those qx-1 perimenters of the past, radio owes its rapid advance. ; The broadcast listener has scarcely touched the possibilities of radio enjoyment unless he possesses a-,short-v/ave receiver and has a knowledge of Mprse code. The greatest distances that thrill new broadcast listeners with faint music, are just beginning distances for the short wave receivers. London may he, listened to almost any, morning on a high frecuency instrument. If we .have a. knowledge of the code, hordes of signals may be copied bringing us press messages, weather reports, ship to shore traffic, and storm warnings. The code is not hard to learn and a little practice will enable one to take down the signals with. f air. accuracy. A good way to memorise Mojse is ,to procure, several dozen blank cards. At the bottom of each card place a letter of the alphabet and at the top of the same card place the Morse character corresponding with ,the letter. In use, the cards are shuffled and are then pulled up from behind far enough to reveal either the letter or the Morse code character.

The recent popularity of the superhetrodyne receiver has ereated the impressiori that this receiver is new, but this is not the case. The superhetrodyne principle was worked.upon by many radio experimenters prior to the advent of broadcasting and the general circuit principles of this type of receiver remain the same to-day as then, though many improvements have been made in details. The radio vacuum tube 01* valve is playing* a more and more important part in our lives every day. It is the modern Alladin's lamp. At one time the valve was confined almost completely to radio receiving circuits and radio transmitters. The vacuum tube has made long distance telephone conversations possible, arid has ben Tesponsible for the perf ection of talking pictures. Its possibilities are limitless, and many more inventions will appear in which the radio valve will be used. An aerial is always more effective when piaced out over eartli with nothing between it and> ground. An aerial over a roof may be very effective, but it can never be as good as one that has no building beneath it. Fading of radio signals does not depend to any great extent upon the transmitter 01* receiver though the fading area of a transmitter alters with different locations. On the lower end of the broadcast band, about 200 and. 250 metres, we find fading extremely bad, whereas round about 400 metres it is not so noticeable though prominent in certain localities. Investigation shows that fading is almost absent above 1,000 metres, though static is sometimes worse. It is possible that the higher wave lengths will be used for broadcasting in the not distant future. Reception during the past week has been average for summer conditions. Signal strength has not been, good for some time, and static is always more or less present. The Australian stations cannot be relied upon to come over above the static level with s ufficient volume for comfortable listening.