Most curly Qs are found on stacked colinear vertical antennas as the 1/4 wavelength phasing (90 deg phase shift) between radiators. As an example you might find a half wave over a half wave or 5/8 over 5/8 wave and an air wound 1/4 wavelength coil in the middle to place the top antenna in phase with the bottom. There are a few antennas out there that are a simple loaded 1/4 wave vertical and the loading coil is an exposed curly Q but those are not as polular these days.
prcguy