WIRELESS

Nelson Evening Mail, Volume LXVI, 11 August 1934, Page 4

WIRELESS

KFI, LOS ANGELES INTERFERENCE BY IYA In the course of a widely-distributed circular the Los Angeles Chamber of Commerce referred to the fact that complaints had been made in New Zealand that it was difficult for KFI to be heard in New Zealand owing to the interference by one of the main New Zealand stations as the result of the wave-lengths now in use, and suggested that an alteration should be made. A copy of the circular was sent to the Manufacturers’ Association, which took the matter up with the Postmas-ter-General. His reply says: “Apparently the president of the Los Angeles Chamber of Commerce has been misinformed. No action has been taken to introduce any new wave-lengths into the New Zealand broadcast allocations which will prejudicially affect reception from Station KFI; but the action actually taken was a redistribution of the wave-lengths which resulted in a wave adjacent to that of Station KFI being transferred from one New Zealand centre to another.

“It is a matter for regret that certain New Zealand listeners find reception of Station KFI difficult owing to their local station occupying an adjacent channel; but it is quite impossible for a new allocation remote from this overseas station to be made, owing to the fact that all suitable channels are at present occupied by other stations operating in Australia or New Zealand.

“It is appreciated that many New Zealanders are interested in the periodical reception from Station KFI; but so long as the same broadcasting band is utilised in each of the several countries bordering tlio Pacific, it is inevitable that listeners, particularly those with non-sclective receivers, will be deprived of remote reception of stations occupying broadcast channels adjacent to that used by their local station.

“The. president of the Los Angeles Chamber of Commerce may be assured that reception of Station KFI is possible except in the immediate neighbourhood of one New Zealand broadcasting station.” TESTING HEADPHONES Headphones should not be tested by connecting them to an accumulator or a dry cell, says “Spark Gap” in the “Australian Journal.” The current from either is apt to ruin the delicate instrument. A small battery for testing headphones is made by sandwiching a piece of damped blotting paper between a sneet of copper and a sheet of aluminium. When the terminals of the headphones are connected to the metal plates a decided click should be heard in the receivers. Another battery suitable for testing headphones can bo made by immersing a strip of zinc and a strip of copper, each about half an inch wide and an inch or two long, in a solution of vinegar. Batteries of this size supply just enough current to test a ’phone without doing it any damage. A GOOD RADIO SOLDER A soft solder, which will melt at a low heat, is essential for radio work, especially for fixing crystals in their holders without injuring the sensitivity of the crystal. It is made, says “Spark Gap” in this month’s “Australian Journal,” by adding three drops of mercury to every ounce of common solder and mixing them well together. This solder will run at a very low temperature and can be used for general wireless work without fear of injuring tire apparatus in any way.