462 



BELL SYSTEM TECHNICAL JOVRKAL 



the other set upon another band. The set is provided with variable 

 filters which accounts for the considerable number of condenser dials. 

 The second bay from the left contains \oice-frcquency output appar- 

 atus, cathode ray osrilIoy:ra|)h and frequency meter. The third bay 



I'ig. 3 — Interior l<i\<rluMii M.nicm 



carries the source of local signal and means for attenuating it, and 

 the fourth bay contains means for monitoring the transmission from 

 the nearby Rocky Point radio telephone transmitter. 



The measurements are of two quantities: (1), the strength of re- 

 ceived field, and (2) the strength of received noise caused by static. 

 The particular frequencies upon which the measurements were taken 



