Home |
Search |
Today's Posts |
#11
![]() |
|||
|
|||
![]() "Roy Lewallen" wrote Very close to a small loop antenna, response is greater to an H field than E field. It does respond to both, however, as all antennas must. As you get farther away from the antenna, the response to the H field decreases in relation to the E field response. At around an eighth wavelength distance from the antenna, the response to E and H fields are about the same as for a distant source. Beyond about an eighth wavelength, the response to the H field is actually *less* than the response to an E field compared to a source at a great distance. The ratio of E to H field responses then decreases to the distant value as you get farther from the antenna. In summary, the antenna responds more strongly to the H field if the source is within about an eighth of a wavelength from the antenna. Beyond that, it actually responds more strongly to the E field relative to the H field than a short dipole or many other antennas -- you could more properly call it an "E-field antenna" in its response to signals beyond about an eighth wavelength. The difference in relative E and H field response among all antennas becomes negligible at great distances; for antennas which are small in terms of wavelength, the difference becomes negligible beyond about a wavelength. But according to W8JI "teachings" there is no way that electrostatic shield on a small loop antenna would work as a shield, attenuating E field dominant signals or noise generated within that 1/8 or about wavelength. According to him, it works as an antenna. Some scientwists can not comprehend that electrostatic shield shunts the predominantly E field generated in the vicinity. It is the FACT, easily observable by anyone building shielded small loop and having TV birdies, PS bricks or arcing noise source within about 1/8 of a wavelength. W8JI wrote: Seriously, precipitation static is caused by corna discharge from an antenna or object someplace near the antenna. The radiated field from that leakage current can be almost any field impedance and will always be a mixture of time-varying electric and magnetic fields. Roy, 'splain to him about this 1/8 or so thing. He still dungetit. 73 Yuri, K3BU |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Passive Repeater | Antenna | |||
Is magnetic field affected by metal conductor? | Homebrew | |||
F/A New Motorola VHF portable antennas (Motorola Branded!!) | Swap | |||
FA Motorola VHF rubber duck Antennas $4.99 ea. Dealer cost $8.70 List $11.80 | Swap | |||
How was antenna formula for uV/Meter Derived? | Antenna |