iiicn rR-r.nrr.xcy amplifiers 



193 



( .i|>,n itiM-ioiiplinj;: / =.',.,/ =/q y\ rinC" 

 wIrtc fo= — >^— . k = 'r =coct'tiiieiU of rmipliin;. 



• Vlc ^ 



V\a\\i\)1 tluis (li-moiistrated llu- ^fiicral shape (it tlu- <un|>lificatii>ii 

 rur\e< for a two coupled tuned circuit ani]ilit"ier, the action of a loosely 

 coupled transformer amplitier for high frequencies will be treated. 



The transformer used in this experiment was made up of two 

 >imilar pancake coils, 2" diameter, wound with 210 turns of solid 

 wire. Fig. shows the circuit diagram. Curves .'I and B in Fig. Ida 



>ue3 



Fig. 9 — .Mothoil of Measurement of Loosely Ccupled Transformer Amplifier 



show the measured amplilication cur\es for a 3 8" distance between 

 the windings. The coupling condensers C were omitted but even 

 then there was some capacity coupling left due to the distributed 

 capacity between the coils. The curves A and B correspond re- 

 spectively, to an aiding and an opposing action of this capaciti\e 

 coupling. Interchanging the leads to either coil changes the amplifi- 

 cation cur\e from one type to the other. 



The self inductance and mutual inductance of the coils were meas- 

 ured at low frequency and found to be: 



L = 2.1X10-' henries. .l/ = .n.^Xin ' henries. 



