Helpful Hints

Radio Record, Volume III, Issue 14, 18 October 1929, Page 27

Helpful Hints

A Tool Protector. WIRELESS experimenters are often at a loss to find a convenient method of preventing steel tools, such as Grills, from rusting. An excellent plan is to bury them in a few handfuls of ordinary tea contained in a suitable tin. Dry tea is one of the most hygroscopic of substances, absorbing all the moisture surrounding it, and if used for some time should be dried out periodically. Spring-cleaning Loudspeakers, LACK of clear reproduction, and falling off in reception is rarely attributed to the loudspeaker, once it has given good results. If a horn type speaker is used, "sogginess" in repro‘duction may, however, be caused by the accumulation of dust and fluff on the diaphragm. Jlectrically, the instrument is. probably. sound, but domestically it needs spring-cleaning, especially if it has: been in use for some time. The diaphragm is thus. hampened by the small wad of material formed; thus producing a "cotton-wool" effect. A Useful Accessory. A POUND of plasticine is a very useful investment for any wireless: enthusiast, ~ A- few examples of the uses to which it may be put are as follow :-With aerial coupling, it is sometimes desired to support a coil at a particular angle,,and at a particular height near another. A small piece of plasticine. can be shaped to ‘give the necessary support. Another small piece will temporarily secure a couple of wires in the desired positions when they .show a tendency to become tangled, or to short-circuit with others. In short-wave work, when valve-hold-ers are dispensed with to give increased efficiency, a valve can be securely supported upside down by. pressing its bulb into a piece of plasticine. Tuning Trouble. MINOR outbreak of tuning trouble and of the local station shifting its setting upon the tuning dials of a receiver, usually occurs every Summer. The trouble usually manifests itself as a slight falling-off of ‘signal strength and an unaccountable variation in the setting of the tuning condenser... Generally the cause of this fault is poor earthing contact, due to the seasonal dryness of the soil, Anyone who has to do-this "dial-dodging" should try the. effect of a bucket or two of water round the earth lead, Odd Tips. -\WVHITE spots’ upon accumulator plates are a sign that sulphation is setting in. , F you use an earth connection to a | water-pipe make sure that the pipe is not painted or dirty, as such-con-nections depend for their efficiency up- | on being. affixed to a thoroughly clean | surface. , HEN loudspeakers are arranged in series with: one another, it is very easy to short.one of them: by means of an ordinary on-off filament switch. GRDAT many failures to get good reproduction arise from carelessness with the grid-bias battery or its leads. s