The Slim-Jim makes a great temporary aerial for use in a hotel room, perhaps hanging from a curtail rail. It also works great as a /P aerial when placed up a non-conductive pole (like a telescopic fishing pole). The Slim-Jim is velcro-tied to the pole at around 2/3 up and used with my FT-60 handheld for local QSOs on 2m/70cm.
A Tri Band Antenna for 2 meters, 220 MHz, and 70cm Antenna Without Radials By: Edison Fong (WB6IQN) US patent –9,608,336 QST March 2017 . ... to the Slim Jim. Every ... The design uses a matching system like a j-pole antenna. This is called the j integrated match (jim) the antenna itself is very slim hence the name Slim Jim. Designs for these antennas date back to the early 1930's the best I can tell. I have found them in QST magazine as far back as the 1940's. Comparison with Dipole. The standard of comparison vertical antenna is a vertical 1/4 wave dipole with a ground plane. Using an example model from the EZNEC files with 45degree radials elevated 5 wavelengths, the dipole was compared to the Slim Jim model.