Volume of Signals

Radio Record, Volume IV, Issue 38, 3 April 1931, Page 2

Volume of Signals

~3 Oe * 4 A VERY interesting fact regarding the +% volume of signals received by listeners on amateur bands may be somewhat cleared up by the following explanation. One would naturally not expect to hear an amateur station with 100 watts come in as loudly as a 500 watt B.C. station, but omitting skip we find that the B.C. station, say, on 720 k.c, transmits 720,000 -eycles per second, and an amateur 8,500,000 cycles per second. As the electromotive force generated in a generated circuit is proportionate to (1) the field strength, (2) speed of ‘eutting, and (8) the number of inductors, it will be readily seen that _ the B.C. station sends out 720,000 waves, and the amateur 3,500,000 per second. Therefore the listener is receiving five times as many cutting lines of force per second through his aerial than from the B.C, station. Working this out, the amateur with 100 watts would be giving approximately as much electromotive force to the receiver as the 500 watt B.C, station; field strength also may be such as to work the receiver to maximum in each ease. It is quite possible to receive a low power short-wave station as loudly ag a medium power B.C. station. . : ‘Skip-assists the shorter waves by hay- ' ing the field strength much: greater at "the reeeiver than is possible with the longer waves.-R.. Clark (ZL2AW).