Fisher F Series Vs The Minelab Xterra 705

[HardPack]

Yes sir, it does for me,  

Appears we have completed the full circle on the benefits of a MD to display Discr TID while in true all metal mode and fast target separation.

After reading your review and posts on the Makro Gold Racer apparently it has those features. Great write up Steve, I’m going with the Gold Racer to fill out my hand.

GB,

With the XT705 in Coin/Relic mode I detect in Discr AM and shift between AM and notch prior to deciding to dig or not.

[GB_Amateur]

This thread was almost dead and buried a day ago and has sprung back to life in a big way.  Lot's of good info and explanations -- the main reason I monitor this site, to learn so I can become a better detectorist.

With repeated hints I think I'm (hopefully) starting to see where I've been going wrong.  Apparently gain settings have a non-linear effect on the wraparound 'problem'.  The full scale of the gain on the Minelab X-Terra 705 is 30 but I always have gotten noise (maybe EMI, kinda sounds like that) the few times I've set it there.  I typically run in the 25-27 range and the detector seems to be nice and well behaved in that zone.  But it's sounding like I'm fooling myself.

I tend to think in the analog world, but this may be the source of my problem.  Turn down the gain and everything is affected the same way -- that has been my thinking.  Iron is still there; copper, etc. are still there, wraparound is still there, just with less strength and/or sensitivity (and the fear sets in -- with corresponding loss of depth).  In the digital world all that is so overly simplified as to be dangerous.

The other thing I've wrestled with is this:  if iron gives both low conductivity (as it should, or at least as we want it to) and high conductivity signals, how do you distinguish that from two separate but independent targets, for example a nail and a coin close together?  In my case it hasn't been so simple that the high signal is above coins -- sometimes the TID (VDI) is right where a real US coin is located.  I notched off 48 (0.999 fine silver coin) and still got positive response.  I notched off 46 (US silver dollar) and still received positive response at 44 or lower.

The good news is that I've installed a testbed in my backyard with variable depth and separation capabilities (I promise to make a post on this sometime this winter giving the details -- it's not your typical test garden).  When that is completed I'll be able to do a lot of experimentation and hopefully figure out the difference between simply iron wrapping around and two separate targets, one of which will reward me for digging it up.  Stay tuned.

[scoopjohnb]

Their is something weird and wonderfull with the disc in these digital detectors. I'm mostly talking about the minelabs because I've got the most experience with them.

Run it in All Metal, all notches accepted, no disc pattern and you are telling your detector. I want an ID on everything AND I like everything just as much.

 

Run a little disc, iron disc for example. So now you are telling your detector. I want an ID on everything BUT I'd much more prefer the non-ferrous. AND HERE IS WHERE MINELAB EXCELLS. At least in my opinion. They will amplify, make more audible, make the sounds more easier to understand for the NON disced out part of the signal.

That is what makes them so good in trash when you add a little disc, they try to see the other stuff hidden in the signal :-)

 

High gain, deep targets, oh dear oh dear, missing those deepies. Slow controlled sweep and 15-17 gain in my dirt, at the beach "dry sand" I go ballistic 23-27.

If you would like to have an idea what your detector is listening to, before its electronics do the magic. Listen to the ground balance channel :-)

[Steve Herschbach]

When in doubt, dig it out. You will never find a machine with perfect discrimination. Tests are good but you cannot duplicate the infinite combinations of ground and targets that can be under a coil in full 3D glory. I hunt by ear and so to my mind it is all about having plenty of audio information delivered to me. I generally prefer not to block any targets but to hunt purely by tones, and the more tones the better. Blocking or notching targets prevents vital information from reaching my ear. I am not saying I never do it however. There is a time and place for everything when detecting.

[HardPack]

GB,

You mentioned the XT705 "99" tone setting. I don't recall if you said you were actually running at "99" tones. I read in another post that running at  2 or 3 tones may lessen the wrap around issue.  I normally run 4 tones but next time out I am going to step down to 3 tones and give it a try. I want that mid tone just in case. Good thing about the XT705 it is easy to toggle around to investigate a target. Recently I've been hitting a few can dumps looking for the silver. I'll run in Disc Notch to reduce the iron signals listening for a good hit. If I think I have one I toggle over to Disc AM.  l then hit the target from different angles listening for a good repeatable signal.  I dig can lids all day long.  When prospecting  I'll run AM without any iron mask at 4 tones  then if I think I'm over an iron or brass target I'll toggle over to Disc to take a look at the TID and circling the target.

Steve & Scoop are right, it took while to let my ears do the deciding .

[GB_Amateur]

2 hours ago, HardPack said:

You mentioned the XT705 "99" tone setting. I don't recall if you said you were actually running at "99" tones.

I started out with 4 tones but switched to the max multitone after reading Horton's monograph.  I'll try the lower number of tones again, but my recollection is that I first noticed wraparound in the early days (4 tones).  I'm going to play with the gain setting and see if that helps.  At some point I probably could/will learn to live with the wraparound -- others have done that (and more).  I'm still not very experienced with the modern detectors so I'm not discouraged, just anxious to get outside and play again.