What's going on with my sensitivity?

[beachdude]

I have been hunting a lake site that is heavily infested with iron nails, mostly in auto, auto +1, auto +2. I have been noticing that the sensitivity has been dropping to 9 (left #) | 5 (green #) at times and the left # rarely goes above 12. Why is that? I am not in saltwater or anything... My targets never seemed to be deeper than 4".

Yesterday I tried experimenting with manual, starting at 20, and then bringing it down to 15 and the 12 because of falsing. I immediately I was getting more depth at this site (targets at 8" and 9") but it was still falsing a lot on iron nails.

I know detectors can false a lot on bent iron nails anyway, but I am wondering what is causing my CTX to run at such low sensitivities on auto. Is it just the sheep number of nails at this site fooling the detector into thinking it is black sand? There is no black sand in lakes, right?

 

[GateKeeper]

What mode were you hunting in?

 

[beachdude]

I am using combined mode or TTF
Wide open screens

- ferrous-coin separation
- recovery fast OFF (sometimes on but thishas no difference on sensitivity issue)
- recovery deep OFF

 

[GateKeeper]

Try using Ground Coin to see if that helps. There might be more mineralization there than you think.

 

[DaveMcC]

Have you done a noise cancellation recently? Cleaned out your coil cover?

 

[jas415]

I hunt almost always on demo lots where iron and other metal is everywhere. I have found that in Auto, +1 to 3, I rarely get more than 3 or 4 inches depth on a target on the screen in these iron infested lots. I switched to manual almost exclusively (most of the time from 23 to 27), and the depth is excellent. Yes, it is noisy and it is open screen, but it works well for me. I dont know if Ground Balance will actually help to a great degree where rusty iron objects are there but would assume it certainly would help in black sand areas.

 

[beachdude]

Thanks for all the advice guys. I will go back today and try ground-coin. I did try ground balancing (on a clean area) ad also noise cancel. When I use the 6" coil it is very stable but I am still not getting a lot of depth. I don't know whether this instability and low sensitivity with the standard coil is happening because the coil is just taking in more information than the smaller one..

 

[beachdude]

Well I think my 11" stock coil is defective. Sensitively drops to 2 and 3 in auto, and it falses like crazy now. My 6" coil works perfectly in this same site with sensitivities15-18 in auto. I think I will have to take it back to the shop to get fixed or replaced.

 

[beachdude]

Got a RMA# and sent the coil off to Minelab in the US for service or replacement. I hope they get it back to me soon because there aren't many days left in hunting season.