RADIO NOTES

Rotorua Morning Post, Volume 2, Issue 261, 28 June 1932, Page 7

RADIO NOTES

Kathode)

(By

Unusual weather conditions are marring local reception. Static and fading are abnormal for this time of the year, and listeners are looking forward to a return to normal signal, strength. The YA stations are received at good volume during daylight, but the approach of darlcness brings with it a blanketing effect,accompanied by distortjon and periodic fading. The Australian stations are below the usual strength for this time of the year, and good volume is only possible with a powerful receiver. A return to clear, frosty nights will usher in normal conditions, and until then listeners must not hasten to bl.ame thpir receivers for indifferent • performance. The transmitters stall at the° Winter Show proved a wonderful attraction and a great success. Messages' were received and despatched to England, Scotland, Hungary, Malay States, South Afriea, South America, Canada, United States, and all over New Zealand. The operators at ZLICL, ZLIGL and ZLIBN have been working overtime to get the messages away, and they now report "all clear." Continuous operating periods have been maintained by these stations from Wednesday, 22nd until Monday, 27th, and it has been necessary for the operators to remain at the key until early morning hours. This work has been done entirely free of charge, and the local transmitters are to be complimented on the efficient manner in which they have conducted the work. The modern trend of radio is to use more than one loud speaker to each set. Two speakers, with their natural periods slightly staggered, will give better reproduetion and increase the acoustical output from three to six times. The use of three or more speakers would further improve reproduetion. With one speaker designed to reproduce the high notes, a second one to reproduce the middle frequences, and a third to reproduce the "lows," almost perfect reproduetion would be obtained. The reception of short waves -is interesting though sometimes tedious. A knowledge of how to tune is essential to good performance, and the following rules should help short wave listeners: — 1. Short wave stations are usually widely separated. Don't expect to find them all over the dial. -2. Tune carefully. A short wave station may be tuned in or out over one degree of the dial. 3. Don't expect to hear a station simply because it is on the air. Many conditions govern short wave reception. 4. If a station is received poorly today, it probably will be O.K. tomorrow. 5. It is important to tune slowly and keep re-action near oscillating point. 6. Don't pass a weak signal. It may be tuned to good strength. 7. A general rule is to tune for stations below 40 metres during daylight, and above 40 metres after dusk. The whole domain of physics is involved in theSscience of radio, and the apparatus in use to-day uses practically all of the physical phenomena capable of being controlled by science. Sound, heat, light, electrostatic and electro-magnetic changes, together with the dynamics of moving parts are all linlced together to build up the science of radio. A study of radio will give one a -greater understanding of the workings of nature and marvels of the universe. A new type of record has appeared and no doubt will prove popular to lovers of reeorded speech and music. This new type of record is "long playing," and is made of a synthetic resin known as durium. A new method of recording, known as the "rnicro-channel" process, permits twice as much music or speech to be used as usually reeorded, and it is claimed that the discs will last three times as long as the old style of record. Conditions on short waves have been exceptionally bad during the past weelc, and the local transmitters have found it necessary to relay all European messages via America. Under normal conditions these jmessages would have been sent direct. but abnormal conditions have blotted out reception of all European stations, even though the New Zealand signals may be heard in England. The 40 metre band is practieally useless at present for long distance work, though the 20 metre band is showing signs of returning to normal. ,, Besides producing distortion, the overloading of a broadcast receivei will cause mechanical injury to the loud speaker. Be satisfied with nor mai volume. "Kathode" examinec a receiver a few days ago that hac been literally ''shaken to pieces" bj opening the receiver out on a loue signal. .