BITS ABOUT BROADCASTS.

Manawatu Standard, Volume LVII, Issue 9, 9 December 1936, Page 3

BITS ABOUT BROADCASTS.

NEW LISBON STATION CALLING. (By “Microphone.”) Interest on short-waves has been whetted for listeners to whom distant stations hold fascination by the appearance of a new Portuguese broadcaster, apparently of high power. On Tuesday of last week, when traversing the 30metre hand, the writer discovered a strong signal with gramophone records at 6 o’clock. The programme lasted until after 7 p.m. and was interspersed with announcements in Portuguese, English and French. The station, according to the announcements, is CSW Lisbon, “the new short-wave station transmitting on 30.18 metres, 9.94 megacycles per second.” It was stated that reports would -be appreciated, these to he sent to the National Broadcasting Station. Lisbon. It has .been stated that this is simply a new wave of an old station, hut the writer has not been able to track it down in logbooks, and the announcer was explicit that it was a new transmitter. At the- time the signals were as strong as the usual output of Radio Coloniale. Paris, but the station has not been heard since. ULTRA-SHORT-WAVES. Occasional reference has been made in these notes to the advances made in ultra-short-waves (those below 10 metres) by amateur stations in New Zealand, Australia, and America, ns a result of which remarkable distances have been covered on low power. A Special Service message to this column

from America, in which Mr S. G. Taylor, a foremost authority, deals with the subject, is of interest. He points out that one important advantage is found in the fact that the range lying between 3 and 10 _metres is, in terms of frequency or kilocycles, a vast domain. So vast, indeed, that nearly four times as many station channels are provided in this narrow span as now exist in the entire existing broadcast range. This is stating the case very conservatively, because the limited distance range of stations operating on tlie.se wave-lengths will permit many to operate on the same frequency without interference. At the present time a moderately powered broadcast station operating on a wave-length of, say, 31 metres, has a world-wide distance range and therefore no other transmitter can be operated on the same frequency without causing interference. On the other hand, a station operating on a wave-length in the vicinity of 5 metres, for instance, could operate on the same frequency with hundreds of other stations throughout the world, spaced not closer than approximately 300 miles apart, with no interference suffered by any station or any listener. The frequency range included in the wave-length hand between 3 and 10 metres is 70,000 kilocycles wide. On the h'’*is of individual channels 10 kilocycles wide, as normally employed by broadcast stations, this would mean 7000 more channels made available for local broadcasting or whatever other type of service might he desired. In the entire radio spectrum now in use between 15 metres and 10,000 metres there is room for only approximately 2000 such channels. If the new ultra-sllort-wave range were to bo extended down to 2 metres instead of 3 metres, another SOOO channels would be made available, each 10 kilocycles wide. It is estimated that for good television transmission a single station will require, for combined “sight and sound” operation, a I'ail'd width four hundred times greater than that required by an ordinary broadcast station. Obviously there would be no room for such a demanding service in the present radio set-up, but on the very short wave-lengths there is plenty of room and it is therefore recognised that television assignments must bo made in the range below 10 metres. In fact, many have already been made in European countries as well as the United States.

Ten-kilocycle channels for long-wave broadcast stations have definite limitations—and this i» oven more true of the 9-kilocycle channels used in Europe. They will not, for instance, permit high-fidelity broadcast transmission because the transmission of the full range of musical tones 'requires a channel at least 15 kilocycles wide. Already in New York City provisions are being made for harbour craft to have ultra-high-frequency telephones on board by means of which captains of these craft can telephone direct to any land telephone. This is an extremely interesting development and it indicates one type of radio progress that we may expect during the next few years. To serve this purpose a telephone central office has been established. just like any other telephone central station in New York City, except that it is equipped with radio receivers over which telephone messages from boats equipped with suitable transmitters are received. THROUGH THE MICROPHONE. A new Australian National relay station is now in service. Tt is 4QN Townsville and works with TOGO watts on 500 metres, 600 kilocycles. It draws its programme from 4QO Brisbane through a land-line 850 miles long—twice the distance from AVellington to Auckland by rail! On the 31-mctre band listeners have been puzzled to identify an Eastern station, variously believed to be Japanese or Chinese. It is definitely ZBAV Hong Kong with its Chinese session

of music and news. At 10 ".m. the announcement, with the call, is made. The Berlin stations are apparently appealing to New Zealand and Australian listeners, as is evidenced by the large number of letters answered nightly. The most friendly announcer is “Harmonica ‘Walter,” who intersperses his calls at 7 p.m. with selections on the mouth organ. Tt is well worth keeping an eye on the Moscow station CRNE-’phone) on 25 metres. At the week-end an unusual programme was heard as a relay from the Bed Square of a huge parade. Radio Coloniale (Paris) has improved immensely on the evening sessions .and at 9.45. with the English news session, is steady and clear. Chimes of 10 p.m. from the studio are broadcast. Mr Warren Penny, the Sydney announcer who was recently seriously injured in a ’plane crash, is well-known before the 2CH microphone. He was recently engaged to be married. Also recently engaged is Miss Hilda Scurr. a featured player in “Khyber” and “Khyber and Beyond,” heal’d from 2BL earlier in the year as serials ; she plaved the heroine. Those who were in close proximity to the pneumatic drills during their use on the new building for the “Standard” appreciated the magnitude of man-made sound, but a new public address unit has been evolved in America that is 1000 times as powerful in output. It is. in fact, as loud as the eruption of Mt. Ivrakatoa in 1883—the loudest sound ever measured—and with an output of 20.000 watts is. the greatest man-made sound so far. It is used for speedway descriptions and is mounted on a tower 100 ft high, being clearly audible a mile away, speech at that distance being word perfect. To-morrow evening, from 11 to 11.30. a special broadcast is being made by KFBF Abilene, Texas. It works on 285 metres, 1050 kilocycles, with 5000 watts. NET Los Angeles (468 metres. 640 kiloeycles—so.ooo watts) is heard comparatively rarely in the Dominion at present, but it is understood special programmes for New Zealand are planned. In the early days of broadcasting there was considerable interference with the reception of 8.8.0. programmes caused by the unskilful manipulation of wireless receivers. That inconvenience has to a largo extent been eliminated, but the engineers of the British Post Office have still to contend with a certain amount of electrical interference, especially in some of the larger towns. Not long ago a great many new electric trolley buses wore put on the streets, and it was feared that the advent of these vehicles might be prejudicial to broadcast reception. The Ministry of Transport has now issued an order that every trolley bus must be fitted with antiinterference devices. This order, has been loyally obeyed, with the. result that, although the number of trolley buses has greatly increased, it has not been prejudicial to the reception of broadcast programmes.