Straight Line Frequency Capacitor

[pwdrive]

Thanks again Al all your research has been noted, I'm getting the picture now, I still can't get to my project yet because of the house diy stuff which is doing my head in at the moment.
Meanwhile here is an interesting link pertaining to bandspread design etc, it covers some ground that you have already covered, some of the maths it a bit to heavy for me, an interesting site nevertheless.

http://electronbunker.ca/Bandspreading.html

Lawrence.