A Radio Miscellany

Radio Record, Volume II, Issue 9, 14 September 1928, Page 31

A Radio Miscellany

x LISTENER has forwarded a letter in which he formulates the theory that when static is not heard during daylight but becomes terrific when night sets in, it is from a very distant source. He claims that the poor conductivity of the ether during daylight prevents the static from being audible at a long range. Anyhow, we all have observed on many nights that statie increases as the night progresses. PCRING those extremely rare occasions when Wellington has been visited by a thunderstorm the writer has tested the effect of a flash of lightning as heard from the loudspeaker. When the lightning was __ relatively close a sharp and loud clap came from the loudspeaker. The sound differed somewhat from the ordinary _ static, and might be likened to a highly magnified effect of switching on an electrie light in one’s house. The latter action will cause a sharp snapping sound to emit from the loudspeaker. OME creditable relaying was accomplished by 3YA, Christchurch, recently. In the morning the British short-wave broadcast station, 5SW, was rebroadcast by 3YA, in the writer’s opinion, more successfully than any previous attempt in New Zealand. In the evening 3YA raked in the Australi stations, one after the other, with Jastonishing clarity and volume, Indeed. one could hardly imagine 2¥FC, Sygliney, was being rebroadcast from Christchurch, so loud and free from parasitic sounds was reception. WELLINGTON is extraordinarily happy in the rarity of thunder-

storms. Take Brisbane as the antithesis. The Queensland capital experiences scores of thunderstorms in a season, and not infrequently the display of lightning is almost continuous for an hour or more. The lightning has often struck forest giants within three or four miles of the city. Listening-in for long-distance stations while a thunderstorm is raging around Brisbane is practically futile. py Australia, pigeon racing is carried out on a large scale, and frequently the stout-hearted homing pigeons meet their doom through flying against a radio aerial. The homing pigeon societies have appealed to listeners, in certain districts, to attach corks here and there along their aerials to render the latter more easily visible to the pigeons. Many listeners have received the suggestion in the right spirit and have followed it. (THE wireless operator of a steamer which visited Wellington a little while ago had a monkey pet who took a keen interest in the redio apparatus, and was of necessity kept on a chain to prevent him getting busy among the radio gear. When broadcast reception was put on a loudspeaker the monkey used to put his head into the speaker to investigate matters, and then shake it to see whether he could dislodge the "devil" within, One day Mr. Mon-

key got his fingers across the loudspeaker terminals and received an electric shock which scared him to such an extent that thenceforth nothing could induce him to venture within six feet of the loudspeaker. A STRIKING proof of the importance of absorption in wireless reception may be gained by the city listener if he takes his receiver to some country position. He will find an enormous increase in the signal strength of all the distant stations he could hear in the city, and in addition he will generally hear many stations that could never be heard in the city. The reason for this is that the buildings, telegraph lines, and electric light lines of the city have a marked shielding effect, which greatly reduces the intensity of wireless waves near them. ANY people are troubled by the question whether dry batteries suffer from not being kept "right way up." The natural assumption is that the terminals are supposed to be at the top, but sometimes the batteries will not fit conveniently into the available space in that attitude, or are not readily accessible. There need be no hesitation about the matter; dry batteries will work equally well in any position. Those who advocate that they should always be kept with the "top" of the zine casing uppermost,

overlook the fact that the outside of a B battery block gives no indication of the way the cells are packed inside, in many heavy duty batteries the cells lie horizontally when the case is placed with the terminals uppermost. Both A and B dry batteries may be arranged in any convenient way. FYUXEL condensers of a larger capacity than about 0.05 may be tested by connecting each side for a moment across a 100 to 200-volt B battery or accumulator. This charges the econdenser, which is discharged by placing a short piece of wire to connect both ends of the condenser, both battery leads having been removed. If a spark: is seen on connecting across, the condenser is intact. A high grade condenser will hold a charge for hours. A condenser that will not hold its charge for a minute is no use for coupling a resistance amplifier. F you are situated near to a broadeast station which you find difficult to cut out, a wave-tray, is the first improvement. Greater facility in cutting out the local is gained by shortening the aerial, as the pick-up is thereby lessened, but the shortening should not be overdone, as the volume vf distant signals will be decreased. Shielding the set with copper is a great help in cutting out the iocal station, and in conjunction wit? a simple wave-trap, leaves little to be desired. SMALL piece of thin fuse-wire, twisted into a spiral, makes an ideal "catswhisker."