AMATEUR RADIO SOCIETY

Evening Post, Volume CVIII, Issue 118, 14 November 1929, Page 27

AMATEUR RADIO SOCIETY

The monthly meeting of the Ama^ fc££ £■£• Society of Wellington was heia in the Cambridge Terrace Congregational Qhurch Schoolroom on Tuesday. In the absence of the president, Mr. Byron Brown, who is on a visit to Austrahay,the ebair was taken by Mr. J- M. Levy, vice-president. The subject of the annoyance occationed by howling valves was much disCussea, and it was explained by a jnember of the trade that the P. ana, y. Department very rigidly tested all types.of Bets on the market in order to prevent the sale of any set likely to occasion interference with broadcast Juitening. He offered the opinion that $he trouble from ■ howling valves was mostly due to home-built sets. The advance of the a.c. type of set in popularity, however, was steadily reducing the howling valve nuisance, ana in time would almost entirely eliminate the trouble. • ■• .

An instructive ana interesting lecture on methods of testing loudspeakers in the laboratories of manufacturers was delivered by Mr. C Liddell, a member of the New Zealand Ajssoeia- , turn of Eaaio Transmitters. Mr. LiddeU who illustrated his remarks with graphs prepared by himself, said that very little real research had been done on the subject. It was-a difficult problem to ascertain the amount of energy imparted to the air on various frequencies from a londspeaker, but he aes- . enbed by diagrams the Phonodeik .Raleigh Disc ana other: ingenious ana successful methods. Many difficulties had to be overcome in obtaining a fairly even distribution of volume throughout. the musical scale, and these were dealt with in detail. At the conclusion of his lecture Mr. 1A&Bell answered, questions, and was acporfed a hearty] vote of thanks.