These are two different issues! I've had the same issue of threshold getting louder as mx5 gets warmer...had it this summer. On a warm day... about 85 deg...the outside of detector will get much warmer when exposed to the sun. As control box gets warmer, you have to keep turning threshold down to keep sound at a low level, which is where most people like to hunt. On a real hot day.....90 deg, & control unit in the sun, threshold sound gets so loud that you can't turn It down any further...no adjustment left. I remove coil, rod, & batteries, and place control box in a refrigerator for 5 minutes....or cool place to allow the box to cool down. Put it back together and it works great! I've repeated this process many times.
I talked with Whites, & sent it in three times...they couldn't
duplicate the problem. They replaced circuit board....didn't fix it.
To their credit, they sent me a new-in-box replacement. It does
the same thing, though I think it's a little less sensitive than my original. I really like the mx5, but I personally think its a design problem. This same problem has been described in another forum, but a fix was never described. If anyone has the problem of mx5 threshold getting too loud on a hot day....try cooling off the control box. Let me know if it works. I was thinking I was the only one having this problem.
Taterbill
its an mx5 what else is there to say.