Just picked up a used in good condition Cobra 2000 Looks to be a 1984 Taiwan model. Problem with it, it is very temperature sensitive. Some electrolytics have been changed out but not all of them. Maybe half of them. Pretty sure I might have a crystal going bad. Once warmed up it will drift to channel 37 frequency counter will read 27.3740 with fine and course at 12 oclock. What crystal would be causing this drift? I'd like to replace it. Thanks for any help.