Tips and Jottings

Radio Record, Volume V, Issue 2, 24 July 1931, Unnumbered Page

Tips and Jottings

NEVER throw away an old valve ‘ holder, coil holder, or similar piece iof apparatus, without stripping it of ‘nuts, terminals, etc. which may come ‘in handy in the future, iF a high negative grid-bias voltage is suddenly removed from the grid "of a power valve the sudden increase ‘of anode current cannot fail to affect adversely the emission. A PRE-DHETECTOR volume control is desirable on a set employing pow‘erful radio-frequency amplification if it is used near a high-power station. ‘Otherwise detector overloading may ‘Bake place.

ND of the commonest cases of "mysterious" faults is faulty contact due to a defective or broken flex lead, QNB of the greatest foes to good reception is metal dust, so be sure to keep the newly-built set free from this while filing’ terminals, ete. AS pentode valves are. much more easily overloaded than ordinary power valves, they should, as a rule, be used with sets with one stage of lowfrequency amplification only. QB of the simplest ways of pre serving the life of your powervalve is to remember that never. under any circumstances should the grid bias plugs be readjusted unless the set is switched off first.