Straight Line Frequency Capacitor

[pwdrive]

Thanks for your efforts on that Al, so the conclusion is that the SLF will not be preserved by the addition of a fixed series capacitor, next question is by how much will it not be preserved assuming the the variable capacitors value is 225 pf and that it needs to be effectively reduced to 150 pf by the addition of a series capacitor, ie: marginal, way out or somewhere in between?
If I had my bench rigged up I could check it out for myself by practical means but that is likely to be some time off at the moment.

Lawrence.