```Dick PA0SE and others, I believe a good way to analyse why more current goes in the bottom of the coil than comes out the top is to resolve the current in to in-phase (I) and quadrature (Q) components. RF ammeters or other sampling current meters display the resultant (R) current (which equals the square root of [I squared plus Q squared]). The I current eventually does some radiating (from the whole antenna system) and the Q current feeds the parasitic capacitance (and is a low loss even though it can not be eliminated). The actual mechanism is lots of small Q currents distributed up the coil, some between turns and some to the environment, so the above simplifies these currents to a single equivalent value of Q at the bottom of the coil. Using 10% as a difference between I and R currents, the Q current calculates as being some 46% of I or some 42% of R. The values are quite sensitive to the observed ratio of bottom to top resultant currents, and the value of Q is quite a significant current. What I'm not so sure about is how to tune in practice for best far field radiation from the antenna, and whether that condition gives a resistive input at the bottom end of the coil. If my above above suggestion is a valid way of working, then it would seem that a secondary matching network could be needed to cater for the Q current? 73, Bob ZL2CA ``````To All from PA0SE Several amateurs have found that the current at the bottom end of the loading coil is higher than at the top (aerial side) of the coil. In my station the difference is of the order of 10%. William, PA0WFO, has a large coil of 8 mH and a 23 m long wire as aerial. He measures 1.5 A at the bottom of the coil en 0.6 A at the top. My theory is that the "lost current" flows via the capacitance of the ``````coil ``````to its surrounding (even a metal object in free space has capacitance). The current at the bottom of the bottom of the coil divides between the capacitances of coil and aerial. I suggested to William he measure the capacitance of the coil and of the aerial. For the coil he found 150 - 200 pF, depending upon the position of the coil and for the aerial 210 pF. But these values do not explain the large difference in current at bottom and top of the coil. In a transmitting aerial the current increases going from the end of the radiator towards the coil. Now to my question: does this increase in current also occur in the winding of the coil? My feeling is that the current at the beginning and end of a coil should be the same; apart from the current that flows via ``````its ``````capacitance to the surrounding. I also have read that the coil should be considered as an aerial with a length equal to the length of the coil. But on 2 km that would be an extremely small aerial, reckoned in wavelength. So radiation by the coil must be negligible. There are certainly experts on the reflector who know the answers. I welcome their views. 73, Dick, PA0SE `````` ```