RADIO NOTES

Rotorua Morning Post, Volume 2, Issue 226, 18 May 1932, Page 2

RADIO NOTES

"KATHODE."

By

Local reception has been marred during the past week by an abnormal amount of static. This condition has been brought about" by "two main factors; firstly, an abnormal amouht of sun s'pots (some of which are visible through smoked glass at the present time), and secondly, ,a sudden change from summer to winter conditions. Empire broadcasting will soon be an estafelished fact, and before long ! re-broadcasts of English progranames | will be a feature of the YA stations. | Contrary to the general belief that j the English short wave transmitter j G5SW was all the British Broadcast- j ing Company could offer the Domi- ^ nions, we are faced with the fact that j that station was not an example of modern technique. G5SW was confined to one wavalength, whereas several are necessary and the restricted use of jjae station did not allow the ; provision of any sort of serviee to j the Empire. G5SW also cost a con- jj siderable amount to maintain and the ■ time has now arrived when this sta- , tion should be deflnitely closed down | and a new station, operating on suitable wgvelengths for different hours of the day and to serve each part of tlie Empire, be established. The B.B.C. have this question before them, and can be relied upon to carry the project to a successful termination The Empire Serviee of the British Bi-oadcasting Commission will use two separate transmitters, operating simultaneously These will be erected at Daventry If required it would be possible to radiate separate programnaes from the two transmitters at the- sarne time, though it is unlikely that this will be done Separate aerials will permit transmission on various wavelengths necessary to reach any part of the world at different times of the day. The actual wavelengths have not yet been chosen, though, in . accordance with the frequencies set by the Washington Conference for short wave broadcasting, the following channels will be used: 50 to 48.8 metres 31 to 31.2 metres. 25.6 to 25.2 metres. 19vto 19.55 metres. 16.9 to 16.85 metres. 14 to 13.9 metres. Arrangements will be made for a quiclc change from one wavelength to another and 'each transmitter will probably transmit on three selected waves Each transmitter will radiate a carrier of 20 kilowatts and up ro date methods will be used to keep each set on its fr-equency Modulation depth and audio frequency characteristics will no doubt be well up to modern standard and something better in short wave transmission and reception is to be expected. These transmitters will be in operation by November, 1932, and before this year has passed listeners in Rotorua will listen to regular programmes from England.

The proper spacing of B class stations is presenting a problem For some reason or other, these stations have been allotted wavelengths indescriminately, and one has only to listen to the hash radiated between 300 and 200 metres to recognise the urgency of a redistribution of frequencies for these stations. Co-op'eration between the licensing authorities in Australia and New Zealand is necessary, as many of the B class Australian stations use high power and are received in Rotorua almost as well as our YA stations The definite purpose of a B class station is to serve. its own neighboui'hood, and the power used by many of the Australians exceeds necessary radiation. A new receiving valve has appeared on the radio horizon This tube is called the Triple Twin, and obviates the necessity of any audio stages. Providing sufficient signal strength is handed to the valve, it will deliver four watts of undistorted output to a loud-speaker when placed in the detector socket More about this tube will appear in these notes in the near future.