Overloading the Radio Stage

Radio Record, Volume IV, Issue 24, 26 December 1930, Page 11

Overloading the Radio Stage

COMMON fault in these days of powerful locals is the overloading of the first valve in the set. Many listeners possess efficient aerials and powerful receivers, and when wanting a local programme tune full in to the station. In all probability, when a signal of such strength is supplied .to the first valve, a screen-grid, for example, either grid current flows or anode rectification takes place. Distortion is, therefore, introduced in the first stage, even though the volume control is turned down to soften the output. The latter statement appears to be a contradiction, but is nevertheless true, as most types of volume control do not stop this form of overloading, as they are associated with the first valve, instead of with the aerial or grid circuit, An éffective way of surmounting the difficulty is to reduce the length of the aerial or fit a condenser in the aerial circuit for the purpose of reducing the input. Hasier still, take off the aerial.