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Radio Record, Volume I, Issue 26, 13 January 1928, Page 14

— Many listeners sec to think that the new power valves give more volume without disturtion on all signals, both weak and strong. This is not true for weak signals In fact, on extremeIy weak signals from distant stations the ordinary 201A type valve will give a trifle louder resnlt than the L7L power valve. But the minute you begin to bring in signals with any degree of volume, the adyantage of: the power valve shows up at once. As the strength of the incoming signal is increased, a point is soon reached where the ordinary 201A is overloaded and distorts badly. Vor imaximum results with any type of power valve, always’ operate it at the highest B and C voltages recommended by the manufac. turer, The 171 valve will give you the most voluine with the least distortion on loud signals, but the 112 valve will be better om weak signals because it amplifics a bit more, although it will mot handle as much volume as the 171 valve One of the most important parts ia a radio receiver is the grid condenser. ew seem to realise its effect on the quality and sensitivity of the receiver. A. poor condenser in the grid leak is worse than no condenser. Leakage in a condenser is one of the chief faults. The importance of this factor is obyious when one recalls the criti‘al nature of the grid leak. This mittst be just so, or the circuit will not. be sensitive and the quality of the output is likely to Le mediocre, or worse, If the grid condenser leaks considerably it effectively lowers the leakage resistance, and the circuit may be a dud as far as sensitivity is concerned. Items of interest to farmers in the prograinmes from 81,0, Melbourne, were the recent broadcasts by Senator Guthrie of descriptions of the woof sales held at Geelong.