Car UHF VHF 145/435MHz Dual Band Antenna

[KX4QC]

Looking for something else entirely, I found this antenna design. Very unusual, and said to give 3.5dB gain on both bands.
Meant for a car, but seems would be easy to use for other applications? -But how does it work??

https://www.aliexpress.us/item/3256802948009947.html is where I found it. Not an ad, just sayin'.....

145-435MHz_car_ant.jpg

Description

Professional Radio Antennas Outdoor Personal Car Parts UHF VHF 145/435MHz Dual Band Antenna CBC-435 for Car 40GF
OOTDTY

Features: brand new and high quality
Applicable frequency: center frequency 145/435MHz (applicable to 136-174/400-480MHz)
Gain: 3.5dBi
Withstand power: 120W
Impedance: 50Ω
VSWR: <1.5

Specification: Material:Metal
Length:Approx.39cm/15.35in
Net Weight:168g

Seems they've sold some and folks generally like them, but they ask just how does this strange thing work? Well, you're an antenna "tweak", let us into the secret!

[KX4QC]

Ha! maybe this is not so wierd after all. There is another described in the Feb '24 issue of QST:

The 2-Meter Astroplane: Modifying a Forgotten 1970s Antenna .

astroplane.jpg

This is revived as a compact antenna for apartment dwellers and portable use.
It is said to resonate on 70cm too, but without the low takeoff angle of 2m.

Check it out in QST or at

astroant_Feb24.pdf

.