Improving the Condenser

Radio Record, Volume II, Issue 24, 28 December 1928, Page 25

Improving the Condenser

"NBARLY "all modern condensers have positive contacts, usually: of the "nig-tail" kind between the spindle and the terminal or soldering tag to which the connection for the moving vane. is made. The resistance cf an old condenser may be reduced by making a = Se ee Se

pig-tail contact ‘from a thin strip of copper :foil coiled into a spiral. The inner end is soldered to the spindle and the outer to the terminal or tag. _ Jiven the best of condensers ceases ta be as efficient as it should when dust is allowed to collect. between the vanes. Should the dust particles happen to.be non-conductors dielectric material is introduced into the strongest portion of the: electrostatic: field, whilst, if, as is usually the case, they are, at any rate, partial conductors, the condenser is more or less short-circuited. ‘The net effect of using a dirty condenser in parallel with a coil in a tuned circuit is much the same as that of using a coil, a clean condenser, and a high resistance in parallel: tuning is flattened -and signal strength suffers.