[Amps] Pi Network Coil Design

[Wayne Rogers]

I'm working on the design of the Pi network for a 4-1000A linear (160, 80, 40 and 20 M only), plate resistance is 5500 ohms, 

The inductance for 160M is 39.2 uH.  I'm planning on using a ceramic former 3.5" by 6.5" (31 T #10 Thermaleze spaced over 6").

That part is easy.  I have a couple questions about taping the coil for the higher bands.  For 80M the inductance required is 19.6 uH, half the 160M value.  So I assume that if I tap the coil at the 50% point I'll have 19.6 uH.  Do I need to give any consideration for the end effect of the shorted out portion of the coil?  Whatever the answer I assume it will apply for the higher bands (40 and 20).

Thanks guys and 73, Wayne N1WR