Antennae thread widened
The antennae connection in my Sportster 4 is widened due to using the wrong plug n play docking station. I know this because the docking station in my truck is nice and snug with no issues. When I transfer the unit to my car/boombox, I get "no signal detected". When I gently pull the unit forward in those docks, it gets a signal. I often have to wedge a paper clip behind the unit and dock to have it stay.
Any suggestions without having to buy a new receiver?
The "wedging" you have been doing is about all I know that will work, but performing this will cause the into to possibly speed up it's dying process. Replacing the unit is your best bet at this time.