198 



BF.LL SYSTEM Tl-.CI IX/C.I L JOVRXAL 



of the wave form distortion variation that occurs from day to (la\'. 

 All these records were made at Stamford, Conn. 



Strips 1 and 2— May 15, 1924— 4 ::3() a.m. 



Strips 3 and 4— Jan. 23. 1925—5:30 a.m. 



Strips 5 and 6 — Jan. 24, 1925 — 6:15 a.m. 



Strips 7 and 8— Jan. 24, 1925—8:00 a.m. 



There is a marked difference in the records obtained on January 23 and 

 24, which were made at the time an effort was being made to determine 

 the effect of the solar eclipse on radio transmission. The peculiarly 



Time 



Fig. 42 — Slow record of signal detected from tone modulated transmission taken on 

 dilTerent days showing the changes in the character of the distortion 



twisted appearance of the record obtained on January 24 is not very 

 common in the records obtained. Most of the records have character- 

 istics similar to those shown in Fig. 37. In the January 24 records 

 there is a marked change in the characteristic configuration of the 

 variation. 



In order to obtain a record of the amount of wave form distortion 

 resulting from frequency modulation present in the detected audio 

 signal the circuit arrangement shown in Fig. 43 was used. This circuit 

 was designed to analyze the wave form distortion when a 250-cycle 



