Hi Ray Dio,
ah yes, DDRRs,..thats the name was trying to remember, some used a PCB for the Top 'capacity hat'
Others, used a sheet of Ali. bent twice, to form the vertical bit, and the Larger top hat
https://www.n5dux.com/ham/files/pdf/DDRR%20-%20Directional%20Discontinuity%20Ring%20Radiator.pdf
https://discover.hubpages.com/technology/What-Are-the-Pros-and-Cons-of-DDRR-Antennas

Because they were so small (at band3) to get it resonant, had Two trimmers, to tweak it
to peak at the two different RX and TX freqs,..I have even seen, a giant version for 68-88 Low band
From what I remember, they were a good bit down, on a quarter wave vertical, due to losses suppose

The same idea, But Huge, was the Capital Radio's King David Ship Antenna, with the hinge up sections
http://www.offshoreradiomuseum.co.uk/page446.html

Rod Watts