There were a batch of the small antennas that had problems. I had to have mine replaced and I recall Ludwig had the same problem.
My 196 and now 296 actually works perfectly in my Cessna and all my cars on the internal antenna.
If youa re getting no recepetion at all or a very poor reception then it may be worth you getting the arial changed. I also found the connectors on the external arial or not very resiliant either. I do 300+ flights a year and remove the unit from the plane each time and this wears the gold plate from the pin in the centre of the connector which then means the antenna starts to become unreliable. I am on my 3rd external antenna.
I do have to say that I get all of my gear from Harry Mendelsohn who provides the most stunning service I have ever come across and when I have had problems like this has changed the parts without question same day.