The K40 Base Loaded is a Super Antenna but it has a One Fatal Flaw.

If the K40 is Trunk Lid, Magnetic or on a Angled Truckers Mount, there is NO PROBLEM.

If the K40 is mounted in a drilled hole on your vehicles roof it will fail!

Yes, it has happened to me repeatability until I gave up. The base coil black plastic case cracks after about 2 years. You change it under guarantee and it will fail again. The problem seems to be in the flexibility of a thin metal roof. My Jeep Commanche has a sturdy roof but the K40 failed 4 Times. The problem was a cracked base. If you would see the thickness of the base you will understand, it is too thin. The whip antenna has no taper to keep it from bending. It put a lot of stress on the base, that coupled with a thin rooftop causes the break.

INSTALL A K40 ROOF MOUNT AT YOUR OWN RISK - I TOLD YOU SO!

Since the majority of installations are Trunk Lip Mount (No wind here) or Magnetic Mount (Strong attachment for base coil) the problem never shows up. But a direct roof mount will break the base. Remember K40 antennas don't come with the foam weather seal for roof mounts, you need to buy it extra. The only solution would be to install a Metal Plate on the inside of your roof to give the base a more solid mount. K40 was sold to another company and not as big as Wilson now.