Found at a recent hamfest, the seller had no info and I can't find anything like it among currently sold antennas. No markings other than a generic power line warning label. If anyone knows, please email me: kc2qfj at arrl dot net.
{Click on any image to enlarge}
Overall length: 9' 8 1/2" 3/4" tapering to 1/2" tubing; "plumber's delight" construction (all elements electrically connected)
Gamma rod: 3/8" x 8" spaced 1 1/2" from element
J-section stubs (my term for them- I've no idea what they're really called): 3/16" rod, 25" overall length, 12" single section, spaced 1 1/2"
The 4 radials were not included, so their length is my guess at 36"
Ground plane to 1st j-section feed point: 24 1/2"
1st to 2nd j-section feed point: 54 1/2"
2nd j to tip: 38"
Based on these dimensions, my guess is that it is some sort of 2 meter collinear, or possibly a 6 / 2 meter dual bander, but I don't have an SWR meter for 6, nor access to any sort of antenna analyzer. Testing on 2 meters showed a slight SWR dip at 146 MHz, but no adjustment of the gamma match yielded an SWR below 3.0. Changing the angle of the radials also did not help.
I reassembled the antenna based on the wear marks. I couldn't tell if the j-sections should be on the same side of the main element as shown, or 180 degrees oppposed, but it made no apparent difference in SWR on 2 meters.