Not enough information. How many turns? How much current through inductor? What core size? What material? Do you already have a particular core you want to design around? What Q do you need from the standpoint of antenna efficiency? Is Q only a thermal issue?
As a VERY general rule, Q is somewhat higher with more turns, so you would want to just use smaller wire and increase the number of turns. Books will not tell you this fact. It's a second order effect having to do with leakage inductance. You should confirm it in your case by making comparative Q measurements. Rick N6RK On 8/6/2012 7:29 AM, Tod Olson wrote: > I am sure [or at least I hope] I could sort through the information > available in books and on the web for the answer to this question, but > maybe someone reading this reflector can give me an 'instant' answer > [preferably correct]. > > I intend to use a powdered iron core toroid as the form for an inductor > which will be used in a matching network at the base of a vertical. The > wire size is #16. Since I have already fabricated and measured a couple of > these inductors, I know the number of turns needed to get 5.5 uH. I need > 11 uH so I put two in series and the expected 11 uH was measured at the > frequency of interest. > > The question I pose is: > > Is it preferably to use two of these inductors in series or use two > stacked cores and the requisite number of turns to get 11 uH? The expected > current through the 11 uH is about 3 amps if the Q is about 100. Will the > Q be different if there are two inductors or one inductor made using two > cores? [same size wire]. > > All comments are welcome. Even suggestions about where to search the web > for an answer or where to look in a book for the equations that will > resolve this matter. Or suggestions on where this has already been > discussed. Or suggestions on the steps to use to quickly get the answer. > > I suspect that this is part of the 'lore' that has been developed which is > why I am asking the question rather than trying re-invent the solution > using first principles. > > Tod, K0TO > >> > > > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
