Brain,

Thanks for the feedback. I may just go with a new antenna if/when I go with another MK4. I'm hoping that it is just the Trimble in this one and that one of the other 2 that I still have will fix this issue. I'm not so sure about your contention that the MKIV failures are uncommon as when I did a search for this issue, a whole lot of threads and people with simialr issues came up. Of course the only ones posting are those that are having issues. Each unit has lasted over a year and it seems like it was different issues with each one, so I'm hopeful there isnt something more going on with my electrical system. Thanks again.