Re: LF: Tapped loading coil design spreadsheet

[John Andrews <w1tag@w1tag.com>]

Jim,

I have always viewed tapped loading coils as a high-pass "L" network, 
where the upper part of the coil leaves a small amount of capacitive 
reactance, representing the "C" in the network. The shunt inductor is 
the part of the coil below the tap. The issue is then to design the coil 
for the inductances above and below the tap. In the couple of these 
calcs I have done, I had accurate R+jX readings of the antenna in 
advance. That may be more difficult for amateur work.
John Andrews, W1TAG