Laboratory Jottings

Radio Record, Volume III, Issue 34, 7 March 1930, Page 32

Laboratory Jottings

Wright Decoster Speakers. Wwe have been able to test one of the Wright Decoster moving-coil speakers, and have been surprised at the splendid results that this speaker is capable of giving. The larger model which we tested was capable of taking 45 watts of undistorted power. ‘Tried against our standard speaker with the same amount of. power fed into both the difference was in favour of the Wright Decoster.. This speaker, which is’ slightly dearer, than the average moving-coil speaker, reproduces with equal intensity a considerably wider range of frequencies than does usually the ordinary dynamic. There is a brilliance about the upper registers. while the bass, though not overaccentuated, is full and clear, Hach instrument comes out clearly. The tapping of the bass drum. and the individual ngtes from wind instruments are in no way jumbled or muddled. ‘Theré is a clear definition present only in the very best speakers. Furthermore, the percentage of electrical energy converted into sound energy is greater than is usual in speakers. We ure advised from the New Zealand agerts, J. A. Smyth and Co., that small home model speakers will be arriving shortly. .The one we heard is for use with sound film equipment and similar installations. "Courtenay" A.C. Local Station Receiver. kK have received from the Stewart Hardware Co., Ltd., one of the Courtenay A.C. locu station receivers. This is a splendidly constructed little outfit, fitting into a neat metal case and complete with a single knob on the front for tuning. The sev is very seusitive, and can be employed within a reasonable distance of the local station by using onl) u short length of indoor antenna, without an earth. The tone of this little receiver is quite good, especially when it is considered that the very moderate price of £10 10s. is asked for it. Results were very pleasing from a cone speaker, for which the set is designed. — The remarkable feature of the sei is its simplicity. One merely plugs into the light socket, attaches the speaker, connects up a. piece of wire to act as an aerial, and the set goes. The tuning’ condenser knob sharpens up the signals and can tone them down if the set is too loud. A high outdoor aerial if very near the local station brings in signals that are rather too loud for the average room. On removing the cover one sees a very neat lay-out. There is nothing shoddy or old-fashioned. The set comprises a crystal detector, and two 226 type amplifying valves with another one of t): same type .as rectifier. The voltage on the amplifying valves is about 65. We should estimate the lives of these valves to be about 12 months or even. more, so that there would be little upkeep. The set costs very little to run, and is very much more economical ‘than a similar battery set. .