[Lowfer] Remote loop tuner

[Zack Widup]

Somewhere I saw a circuit of a tuner for a remote loop that used switched 
capacitors, I think it was eight capacitors, each one double the previous 
value.

I cannot find where I saw the schematic.  I didn't book mark it, 
unfortunately.

Has anyone implemented this design using PIN diodes to switch the caps?

I want to get my LF loop going before winter approaches.

Any recommendations for a good or the best preamp circuit to use?  My loop 
is 20 turns of wire on a PVC "X", each leg is 3.5 inches long, so the loop 
is approximately 5 ft. square.

73, Zack W9SZ