MXT, sensitivity settings & heat ?!?

[srf2112]

I'm wondering if anyone else has run into this with their MXT. I was out hunting last week with the D2 coil in mild/mid ground mineralization. I was able to run the gain up to +1 to +2 before it would become unstable. Several hours into the hunt I suddenly couldn't run the gain past 8 or 9 before it would go straight into overload. My impression was it wouldn't properly ground balance so I called Whites & sent it in. Fast forward to yesterday. I was hunting the same spot with my 6x10DD maxed out at +3. It suddenly did the same thing as the D2 did the week before and I couldn't boost the gain past 9 or 10 before it would go straight to overload. A little while later I was able to crank the gain back up to +2 to +3. After some head scratching I suddenly realized what was happening. When I was hunting in the shade I could max the sensitivity. When I got out into the sun, after I hunted for awhile, the machine would overload if I even tried to turn the gain past preset. Apparently when the machine and/or coil heat up to a certain point this happens. The temp was only around 80 degrees. I tried it several times in different areas at this same spot and had the same result every time. I can't believe this is normal so I'd like to know if anyone else has noticed this problem and what was the fix ? Thanks in advance for any assistance on this troubling matter.
HH
Scott

 

[Larry (IL)]

I think another call to White's is in order Scott, it might not be the coils since it has happened with two different coils exactly the same way. You might have a bad PC board connection that is sensitive to the heat and changing values.

 

[srf2112]

Thank you once again Larry. I was afraid you'd say that...I don't know what I'll do without my MXT if it has to go into the shop. Of course this happens when I've got a spot that's giving up old silver and old gold jewelry (pictures in the future). I guess it's a good time to really get to know my QXT.
HH
Scott

 

[Elton]

I left my coils in a hot van accidentally and both warped inside due to excessive heat and direct sun on coils....Had to replace both coils on my XLT.

What really throws my thought on this being the problem is ' You say this happened in the exact same spot".. That's a bit strange if machine has issues that it would happen in exact area.Did you try any other areas after the machine seemed to malfunction ??. It's possible your getting interference in that area. But I know Mr. Larry's knowledge is far, far greater than mine..so just view this as a remote other possibility

 

[Larry (IL)]

Elton made a good point about it happening in the same spot........could be a large buried steel tank or something causing the overload, but in the same sentence you stated you tried other places too........ I assumed the other places was away from the place that caused the overload. ??

 

[srf2112]

That's correct Larry. The spot I was hunting is very large... acres. It was happening in several spots over a very large area. Anywhere I was working in the shade I could crank the gain to max and anytime I was hunting out in the sun for a little while, in several areas, it would suddenly go into overload if I tried pushing the gain past around 10. Once I went back into the shade for a short time, I could crank it back up again. Very frustrating because the hot areas have all been in the sun so far, no pun intended. I put in a call to Whites today and left a message, waiting on a call back. Thanks again all for the input.
HH
Scott