J STATIC RECORDER 283 



R. A. Watson Watt,'' but it seems that this recorder is mainly an auto- 

 matic counter of static crashes and it would therefore be of little value 

 in U. S. A. where static is mostly a continuous rumble. The reason 

 for the small advance which has been made to date in the automatic 

 recording of static is probably due largely to the lack of suitable ap- 

 paratus. Certainly there has never been any doubt that automatic 

 records would be very valuable. It is just as important to know the 

 static level as it is to know the strength of a radio signal because it is 

 the static to signal ratio that determines the intelligibility of the signal. 

 i\ static recorder connected to a rotating directional antenna system 

 would tell us where static comes from and therefore enable the radio 

 engineer to determine whether it is worth while to construct a directive 

 antenna system. Also the connection between thunder-storm areas 

 and static would make static recording valuable to the meteorological 

 service. There is perhaps no reason why a suitable static recorder 

 should not make it possible in a few years to obtain a daily static 

 forecast just as we get our weather forecast now. 



The question is then, what would be the best way of obtaining such 

 a record of static? It would, of course, be very desirable to get a 

 continuous record of the actual shape of the static wave, but we have 

 no hope of ever realizing this and will have to be satisfied with the 

 wave forms of a few typical static impulses as given by Watson Watt 

 and E. V. Appleton.^ Besides it would require a tremendous amount 

 of labor to interpret such a record. The recorder described in this 

 paper records the energy received within periods of 10 seconds. To 

 be sure, such an energy curve of static does not tell the whole story due 

 to the fact that the character of static is so variable. Thus, the same 

 energy levels of a continuous rumbling static and of static consisting 

 of separate clicks does not mean that these two types of static have 

 the same effect upon the intelligibility of a speech signal. However, 

 the shape of an energy record will indicate the general character of the 

 static, but whether such an energy record will enable us to obtain 

 absolute quantitative results with respect to the effect of static upon 

 speech signals cannot yet be determined until further exiierimental 

 results are available. 



Requirements of an Energy Recorder 



Let us take the case of recording the rectified current through the 

 receiver of an ordinary receiving set supplied with a local carrier 



3 "Directional Observations of Atmospheric Disturbances," by R. A. Watson 

 Watt, Proc. Royal Soc. A, Vol. 102, page 477. 



* "On the Nature of Static," by Watson Watt and Appleton. Proc. Royal ?oc. A, 

 Vol. 103, page 84. 



