I think it would be good to do Yuri's famous picture with a coil of identical inductance, but that is evenly wound around a T300A-2 iron powder toroid, or the smallest that can create the inductance.
I don't think the actuality is nearly as simple as the opposite arguments. If the coil is spread out so that the field of the first turn does not substantially encompass the last turn, then substantial differences will occur in the current because it's acting more like a miscellaneous wire, and modeling with separate inductors is more accurate, and the length is the issue. This would be the case in Yuri's picture with two RF ammeters on either end of a long piece of coil stock. But, if the field of the first turn completely encompasses the last turn, as in a fully covering winding on a powdered iron toroid, or tight layered turns on ferrite core forms, and cannot be affected by other close fields (like the antenna wire itself) then the fields and currents are substantially forced into self-compliance across the winding. These are opposites. Neither all length or all lump will work properly as the physical details will determine where a given winding falls on a scale between all lump and all length. This is the same kind of issues that occur getting into VHF where capacitors become RLC networks, and you can't use caps in a VHF circuit unless you know the RLC of a cap and account for it in the circuit. Ditto with all wires are now inductors, etc. Once one understands this irritating detail, there are situations where coil stock and wound toroids each display advantages that may recommend one or the other. I think it very unfortunate that the demonizing and name-calling of our current political climate has worked its way into science. It destroys possibilities in both politics and science. If two responsible experimenters get opposite results in what on surface are identical experiments, THERE IS A REASON, which means THERE IS AN OPPORTUNITY TO DISCOVER AND ADVANCE. It does no good at all for the owners of the different results to accuse the other of using satanic rituals to obtain their results. 73, Guy. On Sun, Apr 24, 2011 at 9:47 PM, <[email protected]> wrote: > >> On the eternally recurring argument about current into and out >> of a loading coil, here is the way my simple mind has always >> understood it: >> >> W8JI is correct in that the current into a perfect inductor must >> equal the current out of it. It's a piece of coiled wire so >> where else can the current go? Tom's assumption here is a >> 'perfect' inductor with no distributed capacitance. >> > > He is not correct! > Have you looked at the "piece" of wire - quarter wave antenna, having the max > current at the base and ZERO at the tip? And voltage low at the base and high > at the tip - corona? > Where did the current go? > It is the STANDING WAVE circuit, with superimposed forward and reflected RF > currents creating cosinusoidal distribution ALONG the wire and not the DC > circuit. > Why is it hard so understand that if current can vary along the straight > wire, it can wary along the coiled wire too? > > > Yuri K3BU.us > > >> K3BU is also correct because he is assuming a practical >> inductor, with a finite length and distributed capacitance to >> ground. That's where the missing current is going, through the >> distributed capacitance to ground and hence lower output current >> from the top of the inductor into the antenna. >> >> Both right, so why the disagreement? >> >> 73 >> Tom G3OLB >> _______________________________________________ >> UR RST IS ... ... ..9 QSB QSB - hw? BK >> > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
