Home |
Search |
Today's Posts |
#11
![]() |
|||
|
|||
![]() "Gene Fuller" wrote: Selective quoting can have the same effect as misquoting. If one goes back a few words in the same long sentence it can be observed that the more complete limitation is stated as: "... an approximation for M has been determined by Kandoian and Sichak which is *appropriate for quarter-wave resonance* and is valid for helices with 5*N*D^2/lambda 1 ..." I have already explained that to you twice now, Gene. This is the third time so listen up. They were looking for a formula "appropriate for quarter-wave resonance" and they found one that works for lengths other than a quarter-wavelength. If it worked *only* for quarter-wave resonance, they would have said so. You are confusing a mutually inclusive statement with a mutually exclusive statement. Do you really think the Vf is dependent only on the turn density and not the number of turns? Corum never says such a thing, ... Already asked and answered. He certainly does imply such a thing in Fig. 1. The VF is dependent only on the turn density and the diameter of the coil. The number of turns affects the length of the coil. The length of the coil is NOT a parameter in the graphic nor does it appear in the equation. Does a 1/4WL transmission line have a different VF when it is increased to 1/2WL? Where is the transition in Vf from the ~1 for zero turns to ~0.02 for a resonant coil? Already asked and answered. If you cannot read Fig 1, then you have a problem. The VF in the graphic goes from 0.0 to 1.0. After his long struggle to prove his point with modeling, and achieving only 10 degrees of phase replacement, he abandoned that approach for this latest futile attempt. The voltage was 67 degrees out of phase with the current so we weren't dealing with traveling waves. That's why I abandoned it - because I was on the verge of making the same mistake that W7EL and W8JI already made - trusting measurements in the presence of standing waves. The "missing" portion of the test antenna is about 75 degrees, so 45 degrees would barely squeak in under the 59% precision rule. Once again, there is no "missing" portion of an antenna. The delay through the loading coil is what it is. There is absolutely no requirement that it be a certain number of degrees. What is required is that (Vfor+Vref)/(Ifor+Iref) be purely resistive at the feedpoint. There is absolutely no requirement for the antenna to be 90 degrees long. That is just another one of your many strawmen. I am trying to zero in on the technical facts. What are you trying to do? -- 73, Cecil, W5DXP |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Imax ground plane question | CB | |||
Questions -?- Considering a 'small' Shortwave Listener's (SWLs) Antenna | Shortwave | |||
FS: sma-to-bnc custom fit rubber covered antenna adapter | Scanner | |||
FS: sma-to-bnc custom fit rubber covered antenna adapter | Swap | |||
Current in loading coil, EZNEC - helix | Antenna |