ANALYZER FOR COMPLEX ELECTRIC WAVES 



239 



and 50,000 cycles. The output of the ampHfier tube works into the 

 resistance in the mid-branch of the modulator input circuit. 



Mechanical Construction 



Figs. 8 and 9 show the front view of the complete analyzer as in 

 present use and also the interior view of an individual unit (the 

 heterodyne oscillator), to indicate the method of construction. 



Fig. 8 



Each section is completely enclosed in metal, by having shielded 

 cases in the rear and heavy metal panels in front. Perhaps the feature 

 of most interest in the mechanical construction is that of the hinged 

 front panels. These were made of 1/4 in. aluminum to insure ample 

 strength and rigidity with a minimum of strain on the supporting hinge. 

 Each panel is provided with two thumb screws on the edge opposite 

 the hinge so that the units may be readily inspected. This feature of 

 accessibility is particularly desirable in making periodic inspections 

 and in renewing the "C" batteries, which have been mounted on the 

 panels. The heavy material such as tuning coils has been mounted 

 inside the case. The flexible leads, as shown in the lower corner of the 



