License Exam Quiz #345
de Steve, AE8AT
Valdemar Poulsen was born November 23, 1869 in Copenhagen, Denmark. You probably heard of the spark gap transmitter, and vacuum-tubes, but the Poulsen Arc Transmitter once dominated. Sometimes called the arc converter, Poulsen invented his transmitter in 1903. It was more efficient, powerful, and produced a narrower signal than the spark gap transmitters. It was the first device capable of generating continuous radio waves. Key to the advancement was the use of a magnetic field that interacted with the arc. My AI of choice indicates 1907 to 1918 as the period when Poulsen gap transmitters were the choice for governments and others seeking long-range radiotelegraphy. The vacuum tube, invented 1904, would become the choice after 1919.
https://www.invent.org/inductees/valdemar-poulsen
T3B01 What is the relationship between the electric and magnetic fields of an electromagnetic wave?
A. They travel at different speeds
B. They are in parallel
C. They revolve in opposite directions
D. They are at right angles
G2C08 What prosign is sent to indicate the end of a formal message when using CW?
A. SK
B. BK
C. AR
D. KN
E3A05 How are the component fields of an electromagnetic wave oriented?
A. They are parallel
B. They are tangential
C. They are at right angles
D. They are 90 degrees out of phase
Answers
T3B01 = D
G2C08 = C
E3A05 = C