I recently noticed some new antenna installations on the cars belonging to my local constabulary. I struck up a conversation with one police officer at a gas station; and while he knew nothing about the technical aspects of his antennae, he let me measure the setup. It consists of 4 full-wave 800MHz vertical elements, spaced a half-wave apart from each other (nearest) in a square. I am curious if anyone was ever experimented with something like this for 2m or 70cm (obviously not full-wave). It has gotten me curious.
LoJack. 173 MHz. The equivalent for hams is Doppler DF for 2 m or 70 cm. https://www.lojack.com/for-law-enforcement/
It does sound like the layout for Lojack, but if his measurements are right, the spacing is wrong. Also, an 800 MHz antenna would need to have a coil in it, if it is a straight piece of radiator, then it is not for 800MHz. An 800MHz "full wave" would be around 14", which would be pretty close to a QW at 173MHz, but not quite.
Adcock array. Yes, that's for LoJack. Hams have used them for 2M Fox Hunting. Want one? http://www.kn2c.us/
