Actually, the Avanti (and later Antenna Specialist) Sigma 5/8 was a better
antenna than the Super Penetrator.

It had an elevated feed and low loss feedpoint. The Penetrator was a good
antenna, but not better.

Master Chief

http://www.a1antennas.com/


I wouldn't hesitate to say this was the best ground plane antenna ever built,
those that ever had one know what i'm talking about. These are rare and hard
to
find. $80 plus shipping for the antenna and instruction sheet.