| Home |
| Search |
| Today's Posts |
|
#11
|
|||
|
|||
|
Asimov wrote:
"He clearly contradicts himself in my opinion." Griffith echoes Terman. Terman writes on page 2 of his 1955 edition: "The strength of a radio wave is measured in terms of the voltage stress produced by the electric field of the wave and it is usually expressed in microvolts per meter." Terman does not literally mean that it is the electric field which is measured. In his handbook Terman says that a magnetic loop antenna is usually the field strenngth meter`s antenna. Terman meant that field strength is quoted in volts per meter. It is irrelevant which field is actually measured as the two fields are locked in magnitude by the impedance of space, 377 ohms. If you know one, you know the other. Terman also wrote on page 2: "The strength of the wave measured in terms of microvolts per meter of stress in space is also exactly the same voltage that the magnetic flux of the wave induces in a conductor 1 m long when sweeping across this conductor with the velocity of light." The electric and magnetic fields serve to recreate each other in their flight from their source. Either could be measured to get the strength of the wave. Neither field directly produces volts in a wire. As Terman says, it is the wave sweeping the wire at the velocity of light, the d(phi)/dt that generates the volts. Best regards, Richard Harrison, KB5WZI |
| Thread Tools | Search this Thread |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Forum | |||
| Inverted ground plane antenna: compared with normal GP and low dipole. | Antenna | |||
| significance of feedline orientation | Shortwave | |||
| Question for better antenna mavens than I | Shortwave | |||
| QST Article: An Easy to Build, Dual-Band Collinear Antenna | Antenna | |||
| Outdoor Scanner antenna and eventually a reference to SW reception | Shortwave | |||