The Crystal and Valve

Radio Record, Volume II, Issue 26, 11 January 1929, Page 27

The Crystal and Valve

HAVING constructed this set, would be pleased if you would answer my few queries,’ writes "E.J.D." (Lower Hutt). "My list of stations is :-1YA, 2YA, 3YA, 4YA, 326, 2FC (Sydney) ; all these stations have been heard at ’phone strength, the eall-signs in each case being given. There are also many stations which I have not heard the call-sign, but heard talking and music. Now with the question :- "(1) On January 2, while listeninging to Auckland and Christchurch, found that on putting one finger on the grid leak that volume was much increased. 1YA and 3YA and some station which I heard music about 10.30 p,m. eepectall¥, this station not being 2FC, ..

"(2) On testing my B battery I found that it contained only 9 volts, though Wellington came through at fair speaker strength. Would the volume of all these stations be increased if I renewed the battery to a 45-volt?" (1) In all probability the grid leak is too small; try a higher value, say, $ or 4 megohm or a H.F. choke. The station may possibly have been 2ZF', Palmerston North. (2) Most certainly increase the voltage on the plate; 9 volts is far too small, although, as you say, 2YA comes in on the speaker. The B battery should not fall below 380 volts.PENTODE.