2N393 

 2N393 



2N393 2NI500 2KJI09I 



tAW — 6)-6V 

 100 



2.7K >680 o.l 



0.5 ± ^IM 

 300V 



•■ II h€> 



o.i 1 — I 



DETECTOR 



OUTPUT 



Fig. 3- Preamplifier schematic diagram. 



telemetered over a single channel. If the most 

 efficient use of one channel for a large number 

 of transducers is required, each nuclear digital 

 transducer in such cases will require a separate 

 counter . 



fc-\#^l 



SHUTTER 



•-■■■.^■-a 



3 



-SOURCE 



Fig. k. Section of sliding shutter transducer. 



When the data rate is low and bandwidth is not 

 a limiting factor, the counter may be used in the 

 system following the telemetry link. In this 

 case the original transducer pulses can be 

 telemetered, in a manner analogous to CW radio- 

 telegraphy, or by frequency shift keying. 

 Although pulse rate telemetry is extravagant of 

 bandwidth, it may offer considerable attraction 

 from a cost standpoint when the transducer is to 

 be expendable . 



MECHANICAL CONFIGURATION 



A cross-section of the sliding shutter trans- 

 ducer is shown in Fig. k. In this transducer the 

 aperture opening is controlled by the setting of 

 a micrometer screw. The range of setting from a 

 fully closed to a fully open aperture is 0.100 

 inch and the open aperture is square. A photo- 

 graph of this transducer is shown in Fig. 5- 



A corresponding transducer with rotary shutter 

 is shown in Fig. 6. The full shutter range 

 corresponds to less than 20 degrees rotation of 

 the drum dial which is read by a vernier. A 

 photograph of this apparatus, with the preampli- 

 fier circuit board visible, is shown in Fig. f . 

 The chamber which contains the source and detec- 

 tor may be evacuated through a valve when desired 

 in order to eliminate air scattering and energy 

 spectrum distortion. 



Fig. 5- Photograph of sliding shutter transducer. 



176 



