Tom,

I don't think that's correct. The velocity factor applies inside the
coax, but not outside. What you have outside is a fat wire in free space.

But you still don't need to fold the shield back if you put a choke a
quarter wavelength from the end of the coax to decouple a quarter wave
of the _outside_ part of the shield. Then it becomes just as if you had
folded back some of the shield. The currents in the center conductor and
the inside of the shield are unaffected by the choke.

73,
Bob AD3K

Tom Bruhns wrote:
The idea of just pulling the braid back over the outer jacket of the
coax to make a 1/4 wave section turns out to not be a great one...
--
Robert L. Spooner
Registered Professional Engineer
Associate Research Engineer
Intelligent Control Systems Department

Applied Research Laboratory Phone: (814) 863-4120
The Pennsylvania State University FAX: (814) 863-7841
P. O. Box 30
State College, PA 16804-0030