Home |
Search |
Today's Posts |
#21
![]() |
|||
|
|||
![]() "Richard Fry" wrote "Reg Edwards" wrote Just to start an argument, why is it that EZNEC shows zero gain for a vertical antenna in the horizontal plane? Whereas, all your diagrams show maximum gain along the horizontal. ____________ EZNEC shows the same patterns/gains as in the plots I posted, when its models are set up correctly. RF ======================================== The model for a simple vertical above ground is simple enough. Perhaps YOUR way is incorrect if the pattern disagrees so strongly with EZNEC. ---- Reg. |
#22
![]() |
|||
|
|||
![]()
"Reg Edwards" wrote
"Richard Fry" wrote "Reg Edwards" wrote Just to start an argument, why is it that EZNEC shows zero gain for a vertical antenna in the horizontal plane? Whereas, all your diagrams show maximum gain along the horizontal. ____________ EZNEC shows the same patterns/gains as in the plots I posted, when its models are set up correctly. RF ======================================== The model for a simple vertical above ground is simple enough. Perhaps YOUR way is incorrect if the pattern disagrees so strongly with EZNEC. ---- Reg. _______________ Reg, My models agree with theory and measured results, as have been developed and well-proven for 60+ years in the broadcast industry. If you doubt my plots, why not send them to Roy Lewallen ask for his comments? You might also ask him to tell you how to model these configurations properly using EZNEC. I'd explain it, but probably that wouldn't be acceptable to you (plus you didn't ask me). RF |
#23
![]() |
|||
|
|||
![]()
Reg Edwards wrote:
Just to start an argument, Things are even duller than usual in Rowley Regis, I see. why is it that EZNEC shows zero gain for a vertical antenna in the horizontal plane? Whereas, all your diagrams show maximum gain along the horizontal. C'mon Reg, it's only been three months since you last asked this and got it answered(1). The time before that was four years earlier(2), and before that multiple times going back at least to 1998(3). At the rate you're going, you'll be asking it weekly before long. Getting tired of promoting "TLI"s, grumping at "Gurus" (while carefully excluding yourself, of course), grousing about Americans, and asking "Who's Kraus"? C'mon, be original. Surely you can think of a new topic to keep you awake on those long, boring evenings. I've got an idea -- maybe you can use your knowledge to actually help some of the folks who ask serious questions on this newsgroup. For anyone who wants an answer to Reg's perennial question, use groups.google.com to look up the following threads on this newsgroup, where Reg has asked the same question and where it's been answered: (1) "best HF antenna system next to a trailer?", Sept. 2005 (2) "40M Delta Loop Advice Needed:", May 2001 (3) "Raised V's burried ground systems." [sic], Feb. 2000 "Ground Radial system comparisons", April 1999 "Is there", Aug. 1998 "Better for DXing: Beam or vertical?", Aug. 1998 Roy Lewallen, W7EL |
#24
![]() |
|||
|
|||
![]()
Roy, you'll just have to accept the fact that I'm peculiar. But no
more peculiar than other frequenters of this newsgroup. I don't think I do much damage. ---- Reg. |
#25
![]() |
|||
|
|||
![]()
Reg Edwards wrote:
Roy, you'll just have to accept the fact that I'm peculiar. But no more peculiar than other frequenters of this newsgroup. How's this for peculiar? :-) "The movement of energy within the line is complex; in the abbreviated analysis I've had time to do so far, it sloshes back and forth in regions within the line." -- 73, Cecil http://www.qsl.net/w5dxp |
#26
![]() |
|||
|
|||
![]() Richard, I thank you for your time and trouble expended in trying to educate me regarding the field strength from a 1 Kw transmitter at a distance of 1 Km. Your efforts, of course, will not be wasted on other readers of this newsgroup. Very good stuff! But you have misunderstood my attitude towards this discussion. As I have said before, amateurs and professionals alike, all suffer from delusions of accuracy. The uncertainty in prediction of field strength of groundwaves can amount to 10 or 15 dB or even more at extreme distances. When I say my program correctly predicts a field strength of 300 millivolts per metre at a distance of 1 Km from a 1 Kw transmitter, nobody can disprove it. Even the 'bibles' state it as a matter of fact. But we all know how much faith can be placed in 'bibles'. To be of use, all measurements should be associated with an uncertainty. Only then can the originators be judged to understand what they are waffling about. Thank you for your interest. ---- Reg, G4FGQ. |
#27
![]() |
|||
|
|||
![]()
"Reg Edwards"
When I say my program correctly predicts a field strength of 300 millivolts per metre at a distance of 1 Km from a 1 Kw transmitter, nobody can disprove it. Even the 'bibles' state it as a matter of fact. But we all know how much faith can be placed in 'bibles'. To be of use, all measurements should be associated with an uncertainty. Only then can the originators be judged to understand what they are waffling about. ______________ Interesting point of view, Reg. The correct application of physical laws disproves your contention, and the equations that do it are not difficult. Here they a E = SQRT(49.2*P)/D where E = Peak inverse (free-space) field from a self-resonant, 1/2-wave dipole (volts/meter) D = Distance (meters) As radiation from a vertical antenna with its base at ground level is confined to one hemisphere, field strength at that distance over a perfect, infinite, flat "ground" plane is E * SQRT(2). This generates the value of the maximum possible field from a perfect 1/4-wave vertical radiator over a perfect ground plane, which has been proven and used for many decades in the broadcast industry. This is the groundwave field that then is subject to various propagation losses related to earth conductivity, diffraction etc over long paths, once the radiation has been launched. N.B. -- at a distance of 1 km, such losses are negligible for the typical broadcast vertical with its 120 buried radials, regardless of ground conductivity. Why not use the formulae in your program that actually generates the correct value, instead of just saying it does, or implying that your approach is "good enough?" RF |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Inverted ground plane antenna: compared with normal GP and low dipole. | Antenna | |||
Multi-Band Shortwave Listener (SWL) Antennas : Windom - Dipole - Random Wire | Shortwave | |||
FS: Connectors, Antennas, Meters, Mounts, etc. | Antenna | |||
Poor quality low + High TV channels? How much dB in Preamp? | Antenna | |||
QST Article: An Easy to Build, Dual-Band Collinear Antenna | Antenna |