An observation favoring the all metal setting

[BarberBill]

Here's some food for thought, especially if you can handle running in all metal without going bonkers from the trash.
Have done a bit of testing (in air) with several machines. Was primarily interested in target masking and discrimination. What I found has made me rethink my own hunting technique. I used a thin iron, tent peg (just something I happened to have handy). I placed it beside, then on top of and then a slight distance from a quarter. With the machine

 

[Furious T]

Hi BarberBill,
It's good to see people taking iniative and creating their own tests. You're quite right of course about the masking/all metal/etc. Some good tests to do is to gether together as much of the prediominant trash from a particular area, and use those pieces of trash (pulltabs, bottle caps, bits of alum. cans, foil etc) to do the same sort of testing you just did. Then you have some idea what degree of discrimination you need on a particular detector for that area (might be a park or playing field) to miss as little of the good stuff as possible. All my machines go deeper in All Metal than in discriminate mode, but there are some areas which you just cant hunt (to preserve your own sanity) in all metal. Trying something new keeps the mind alert and the hobby interesting! HH

 

[slingshot]

I try to limit the a/m mode to tot lots and schools and parks that I have cleared the trash. The a/m mode ALSO picks up the small gold earrings, pocket knives and other interesting things besides iron.

 

[tvr]

In some testing I have done, I found that I could generally uncover targets that were about the width of the coil from a discriminated out (masking) piece of metal. Was that way with pretty much every detector I tried.

Doing the testing vividly pointed out why my general preference to go with as big of a coil as I could handle the chatter with using fairly low discrimination in trashy ground may not be best way to go. Still need to go with low discrimination, but a smaller coil can move the parameters in a good direction.

If there were multiple targets under the coil that were not masked out, sometimes they blend together and sometimes they can be separated.

Some of the results depended on the direction the targets are approached with the coil and the coil speed. Generally a slower coil speed works better at uncovering targets, but not always. The Tejon's re-tune speed means you can't completely crawl with it, but you can still slow down pretty well.
tvr

 

[Ism]

BB,

I have done some testing in this area also. I found much the same results as you did. I also found that if there is trash anywhere near the good object, the depth of detection is seriously affected in disc mode. Hence, many deeper objects in trashy ground are missed even though they are not masked. In addition (as stated above), the approach to an object can make all the difference. That explains why an area is not thoroughly searched until its been hit from many directions.Testing for myself has made a positive difference in my finds in the field. Thanks for the thread, these tips are important and need to be refreshed from time to time.


Randy