Did You Know That

Radio Record, Volume V, Issue 27, 15 January 1932, Page 23

Did You Know That

eal ¥ one of your teléphone’§ earpieces breaks down, remember that a wire across its two terminals may enable you to listen to the conclusion of the programme on the one earpiece. WHEN plug and juck contacts have been in use a long time they should be examined occasionally for specks of dust, dirt, éte. These may lower the efliciency of the component, which may give rise to crackling if its contacts are not cleaned and scraped occasionally. If you are unable to get reaction when your condetser is all in, except toward the lower end of your’ tuning range, a small fixed condenser, usually .0001 or less, connected across the reaction condenser is an improvisation worth trying. ON some audio transformers it is the practice to provide an extra terminal by means of-which the metal ease of the instrument may be connected to earth, but there is no need to

LT CS OCT CO i Se connect this up if perfect results are cbtainable without such a connection. TT ROUBLH With reaction overlap is often due to the wrong "B" yoltage on the detector, to an unsuitable dete. tor valve, or to a grid leak of wrong resistance. "Too niuch reaction ix worse than none at all, for it is impossible to hear long-distance or good quality signals if your set is oscillating. For accurate tuning on a short-wave set there are many adyantages in mounting a small magnifying glass over the tuning-dial scale,