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BELL SYSTEM TECHNICAL JOURNAL 



As before mentioned the tuned circuit is made up of inductance 

 L, having some resistance R, and a bank of condensers designated 

 by C. The function of the "Condenser Relays" is to connect into 

 the tuned circuit any one or any combination of the 25 fixed con- 

 densers, thus tuning the circuit in small steps over a wide range of 

 frequencies. The input is fed into this circuit as shown at A, and 

 the degree of resonance, that is the response of the circuit at any 



A'icw of Analyzer Ready for Use 



a — Input and tuned eircuits 

 b — Amplifier-rectifier 

 c — Camera motor 



g — Reversing key 



d — Recording meter 

 c — Control box 

 / — Starting button 



particular freciiicnc>- of tuning, is measured by incans of the small 

 transformer 7', the amplifier-rectifier and the recording meter. 



In addition to operating the tuned circuit a few of the air relays 

 are used to operate the control circuits, mark frequency lines on the 

 chart, etc., uses which re<iiiirc(l slight modification as indicated 

 schematically in Fig. 3. In two of these control relays only one 

 diajihragm is used, and the swii( li le\c'r and diaphragtn are fastened 

 together by means of a flexil>le link. It has already been noted 



