Multi-Tapped inductor question

[parabuzzle]

I'm working on a HAM radio antenna tuner for myself and I don't have the money to buy a nice rotary inductor at the moment. So I am using the multi-tapped inductor design with a selector switch.

This is essentially what I am making:


So I am using a 12 position selector switch to control which tap the tuner should use. The switch I have really only has 11 positions because one of the positions is the feed point that is permanently shorted to the center ring so I that point is what I would call "off" because when I put it in that position its not connected to any other pin. I don't want to have an option of opening the circuit like that and I would like to utilize that point as well. So I was thinking that I would connect that point to the output side of the full inductor length and then use the switch to shorten the inductor to different lengths. My question is, will this cause the RF to become reverse-biased in the section of coil that I am bypassing given that I now have 2 paths for it? Is it a problem or is this even feasible? Or should I just be happy with the 11 positions/taps 

This is a simplified design of what I am talking about.. nevermind the components used.. I just used representation parts I found in eagle:



-Mike

[Rory]

Shorting out turns in switched inductors is the norm. Look at diagrams of antenna matching networks in the ARRL Handbook for examples.

[JackOfVA]

Take a read of http://vk1od.net/tx/concept/TappedCoil/ -- good analysis of the difference between open circuit and short circuit of unused turns.

[parabuzzle]

Take a read of http://vk1od.net/tx/concept/TappedCoil/ -- good analysis of the difference between open circuit and short circuit of unused turns.

This is exactly what I didn't know I needed to read

-Mike