[TowerTalk] Glass mount antenna problem

[Bob Allen]

Hate to even say I'm trying to put in a glass mount 2m - 70 cm antenna 
on my wife's car but I am.
Here is the problem, I installed the antenna and couldn't adjust the 
reflected power down at all so I assumed that the window was tinted with 
metal film, removed the antenna from the glass and stuck the coupler and 
antenna together and guess what?? I got the same reflected power as when 
it was mounted on the glass, it also gives the same reflected power if 
the coupler is removed from the antenna. The thing that makes the 
reflected power get even worse is to remove the coax from the coupler.
I can't RF test the coax as the coupler end fitting is one that I don't 
have the adapter for (TNC I think),  I removed the cover of the coupler 
and found magnet wire with (3) 1/4" turns of  16-18 gauge with one end 
connected to the center pin of the TNC?? and the other end connected to 
one end of a variable cap.?? which has the other  end soldered to a 
small plate of brass, I suppose this is the plate that 
transmits/recieves the signals from the antenna.
The question here is, what could be missing that is causing this antenna 
not to work, lets face it the parts count is low so I'm wondering if 
something obvious is missing, it is brand new but can't be returned as 
it sat on the shelf for 3 years before being installed.
Sorry I don't have the model number but it is a PRO-AM that was marketed 
by Radio Shack.
The reflected power was 1.7w with forward about 5w.

Bob
KB1FRW