Are you too sensitive?

[Digger_O'Dell]

Hey all,
I saw a video a couple weeks ago that has had me aggravated and worried about the performance of the CTX in trashy areas. The video is here:

https://youtu.be/gGwqHyUSUI8

I have been going nuts trying to figure out a solution and almost gave up when I had an epiphany today. I was swinging and thinking about how the detector "sees" what's under the coil when I thought about how it not only sees what's under the coil, but also above it and to a lesser extent, around the sides. I decided to run another test.

This time I used a clad dime between 3 inch high blocks about 8 inches apart, with large bloated rusty square nails on top. I set sensitivity to manual and kept dropping the sensitivity until I started getting a signal at a sensitivity of 6. Granted, it only squeaks a high tone, but it's repeatable. I got the best results at 4, and lost it between 1 and 2. At about 4 inches coil to coin, 2 was at the far edge of its range.

Using this information and trying it at the park I was already at, I used a sensitivity of 5. Wow, what a difference! The ground was suddenly very quiet, no falsing, but I was getting more clear signals from among the trash and iron. I knew almost every target I found there before was only 6 inches or less, my find ratio to falsing and obstruction by trash flip flopped.

My suggestion, if in a high trash area with shallow to mid range goodies, try the fast recovery option and drop the sensitivity really low. You might be surprised!

[OxShoeDrew]

I REALLY believe this! The highest sensitivity I ever run is 95 out of 99....and only sparingly. I'm usually down in the low 90s, my machine seems to aurally ID better than when it is higher. As I get near the hole, and trash starts, I go as low as high 70s.

[MangoAve]

I'll agree, although to an extent. Your perspective is on the CTX. Drew's is on his F75. Mine will miss certain targets if the sense is too low, but VDI wont be stable when the sense is cranked. There's a 'happy medium' for any machine. I don't run at 8, and I was missing stuff at 5. So I usually run 7 in the woods and 6 in the parks on the Tpro. The Time Ranger default is 5. I put it to 6 or 7 normally as well. The GTI2500 I believe default is 7 and I put it to 8.5 normally.

[Lodge Scent]

Cranking up the Sensitivity too high is a problem for any machine. Sensitivity levels determine how your machine will respond to small targets....and not just good small targets.....but any small targets. High sensitivity levels will seemingly make your machine go deeper because it will respond to the weak signal from a deeper small target. But of course if your site is infested with LOTS of small trashy targets, your machine will pick up on everyone of them and cause a whole bunch of problems that your machine may not be able to compensate for, even with all its sophisticated filters. Like everyone alludes to above, you need to find that Sensitivity sweet spot to maximize your chances.

[MangoAve]

I will add that I tried using the small coil this weekend at a site I know was very active for many years up until the early 30s. Smaller coil you can crank the sense way up. Although the size of the coil affects the depth making you want to crank it, I noticed that it often overloaded the machine. Even with a small coil it was overloading. I got the separation I was after as I did find a few relics that were hidden, but even those brass buckle/links with one loop perpendicular to the other caused an overload. And sure enough a modern quarter at surface (one I used) overloaded it too. I am sure an LC at an inch depth would too, which I did find an 1840 LC at such depth so it does occasionally happen.