all i could find so far
5/8 Wave Ground Plane Antenna
(210-1133) Specifications Faxback Doc. # 32982
ELECTRICAL:
Gain (Circuit):.......................................................4 dB
Power Multiplication Factor:...........................................2.5
SWR (at resonance):.................................................1.04:1
Input Impedance:...................................................50 Ohms
Radiation Pattern:................................Omni-directional pattern
MECHANICAL:
Overall Height:.............................................Approx. 19'10"
Diameter of Radiator:......................................1 1/4" to 7/16"
Length of Radials:................................................8'7 1/4"
Diameter of Radials:..........................................5/8 to 7/16"
Mast Bracket Accepts:.........................................up to 1 5/8"
Net Weight:.........................................................7 lbs.
Specifications are typical; individual units might vary. Specifications
are subject to change without notice.
looks like you can buy one
http://dxcorner.s5.com/photo4.html