Those 102" stainless steel whips are designed to be used with a 6" coil spring to equal 108" with either a ball mount or a through the roof solid...
Thumping mine didn't help after it got stuck, Cobra 29 ltd classic needle stuck about a 1/4 of the way up the scale.
A external meter doesn't show you incoming rf signal strength that's one of the reasons the radio comes with a meter.
