Got a Cobra 146 GTL that works great, but the thing will drift off once you have it set right side up... But since I adjusted it with the radio upside down, it will stay on frequency and not drift off... Flip it back over, its off lol. Even with the covers on, you can flip it either side and it changes. It takes it a moment as if the crystal itself "settles" due to gravity? I suppose I can overcome this if I adjust the TX while it is right side up and call it a day.