Though my AT Pro works fine for the most part and I'm getting some good finds, I am having similar issues. I figured all along that these issues were normal, but this thread now makes me wonder if perhaps I have a defective unit. Here are some observations:
1. When my at pro hits the ground or a fallen branch, etc. during swinging, it falses, giving a deceptive high tone. Similarly, 100% of the time, when I pick up my md after digging a target, it falses (high tone) as I bring the md near me.
2. Sometimes (30-40%) when I pinpoint a target, it either does nothing or, moreso, the high pitch remains when I remove the coil away from the target. The rest of the time it works just fine.
3. I'm getting a lot of jumpy signals. It will hit some targets with solid numbers, but many other signals bounce from under 10 all the way up to 80s. I know that this can indicate a trash signal (and they usually are), but it seems I get way too many jumpy signals. I think the videos above show this flaw exactly as I am experiencing it.
I will try re-attaching the coil plug to make sure it's tight and will re-wrap the wire to ensure it's snug, but I'm still wondering if I have a defective unit and should send it in to be checked. Do these things happen to you? Thanks.