NOTES

Shannon News, 25 November 1927, Page 4

NOTES

When winding coils at home, it is r well to remember that several factors conjointly determine the natural wave-length obtainable. If the maximum inductance for a miniature quality of wire is desired, the coil should be.solenoil, or cylindrical formation, with a diameter two and a half the length. /

It is safe to assiime- that during the next year or two “B” battery manufacturers will have to face strong competition from the Battery eliminator, which, when properly constructed, lasts indefinitely, operates at a minimum cost, and provides perfectly smooth, non-fluctuating high tension current for broadcast reception.

A transformer .which Is about to burn out generally gives crackling noises in the speaker similar to those caused by a "B” battery. A defective secondary will produce a humming noise in addition, but a primary merely causes the crackling noise followed by silence.

A good make-shift “earth” can be fixed up by country dwellers who can not obtain the use of a waterpipe, and is often in demand. A few yards of wire-netting, buried flat-wise about two or three feet below the surface will make a good earth. The .ground should be kept moist, and the wire running to the earth terminal of the ■,set should be firmly soldered to the wire-netting. The latter should be placed right underneath the aerial .H ' - ;possib)e>, but • this Is not ■ at all es aeutial, y