What is a pigtail antenna?

The typical antenna used in land mobile radio applications has a number of
spiral turns in the center of the element ... similar to the tail of a pig.

And, "NMO" refers to the type of mating / coupler used at the base of the
antenna element.

With an NMO coupler, the antenna element easily can be screwed on or off the
base ... an advantage for going through the car wash, or if you want to switch
elements for particular listening applications.

Jeff Multer
Fort Mill, S.C.