On 9/5/2012 4:17 PM, NM5K speculated:

About 16.5-17 inches long with coax that has a .66 VF.
It's not too critical.

Hummm.. Actually, being as the coax is used for capacitance,
the pf per foot would probably be more pertinent than the VF..
Seems like RG-8 is about 26 pf per foot??? I fergot..
And am too lazy to look it up.. :/
But like I say, it's not critical at all.. You could probably
be an inch off either way, and notice little difference in
tuning.