JFET matching for Chunk Chunk

[warriorpoet]

Alright, building a Chunk Chunk, and trying to decipher Juansolo's method for JFET matching. I did find the GeoFX article, and built up a JFET matcher on vero (link at the end), but I'm not getting anything approaching the values recommended. Most are in the .03-.2 range, and not at all close to the -0.3 range recommended. 

Am I missing something? Is there a calculation I'm not aware of?

Thanks for your help!

Here's the vero I'm using: http://2.bp.blogspot.com/-AbBm9p3sUHk/UBPVCFikwRI/AAAAAAAAB_c/WPCDhKLOPrY/s1600/JFET+Matcher+Compact.png