Rubber duck antenna

[Seminoles]

I bought one of those radio shack pro84 scanners with the head phones when they were $49.95 I use a home made vertical dipole antenna for it so I decided to take the rubber one that came with it apart. It had a small spring wire in the center about the size of a click type pen has but longer and a lot stronger it was in a thick plastic tube with a larger and thicker spring on the outside couldn’t even bend that one both screwed onto the center of the BNC connector shaped like two different screws both were either gold or copper plated. Cut the tip off the rubber cover and screwed an old rabbit ears TV whip into the larger spring worked better on the CB channels. Now for some brain picking of the great antenna engineers out there on this forum since both springs are the radiator connected to the center wire of the BNC connector and both springs seam to be the same length might be wrong there, one thicker then the other dose this set up increase band width? I don’t think they lower resonate frequency since they are one inside the other both have the feed point at the bottom not one connected to the end of the other making it a longer wire. Is this working like if you were to put a 2m whip next to a 440 whip on the same mount two whips on one coax?