All, I am looking at building a stacked 5/8w vertical for 2 meters. I have seen a lot of matching stubs used in J-poles that are electrically 1/4 wave. Some are coils, some are hairpin style, and some are hairpin style wrapped around a circle as opposed to straight out, and then some are 1 turn coils. Another source I found in a review of a Diamond stacked 2 element 5/8w base antenna they determined the "phasing inductor" was about .7uH. I don't know how you can give a measurement in inductance that is going to amount to any accuracy in an RF environment. Inductance and electrical wavelength don't necessarily go hand-in-hand. Impedance is a factor of resistance and reactance. Without knowing the resistive component of the impedance the .7uH inductance is irrelevant. I suppose one could work that backwards to estimate the resistive component of the complex impedance, but there are still too many variables in everything for this to be any reliable/accurate measurement. I would be curious on methods to match the feedpoint also, that do not require the matching stub like a J-pole. I want to build my antenna around PVC pipe - 1" for the base/longest section, then taper to 3/4" for the top section. I don't mind wire or a coil wrapped outside of the pipe, I just want a good method to phase. As far as tuning the input for this - I was thinking about making a capacitor out of two parallel pieces of insulated 12g Romex strands taped together, then trimmed to tune, and a relatively fixed inductor (I think it is going to be easier to tune the capacitor than the inductor - so leave the inductor fixed in place/value) to complete the L network. Does anyone see any issues with this? I can measure both inductance and capacitance so the values can be known values. In the end, though, the SWR is going to be the telling tale. I may be able to get an antenna analyzer that shows the impdance (complex), but that is about a 50% shot at this point (if it can be found and if it works...).