Etrac using conductive audio versus ferrous audio (not even close for useable effective depth)

It seems some think the 2-tone ferrous audio tone mode as opposed to using multi-tone conductive tone mode is better when detecting coins/relics. For those of you that actually believe this, try this experiment.
Drop a dime on clean ground and place your etrac in manual 25 sensitivity multi tone conductive mode. Put your headphones on and start sweeping the dime and continue to sweep progressively raising your coil over the dime. You should hear the high (dig me) tone to around the 9-10 inch mark approximately. Repeat again but this time instead of concentrating on your headphone tone watch your screen and pay particular attention to the ferrous numbers as you sweep while raising the coil. Now go into the 2-tone ferrous mode. Again with headphones on, start sweeping the dime and continue to sweep progressively raising the coil distance. You should hear the ferrous tone start changing at around 5-6 or so inches. Some sweeps at 5-6 inches will be the higher ferrous tone, others will be the ferrous grunt (no dig) tone. Granted this is not even an ideal airtest, but it does shed light on changes that begin to take place as distance between target and coil inrease. Even sweeping the dime at moderate distances with the perimeter of the coil will drive ferrous numbers up. Remember in 2-tone ferrous audio the etrac must process a signal and report a 17 ferrous or lower to get the higher tone (possible dig me signal). Now add a little iron, nails, mineralized soil, and depth and who knows what ferrous value would be processed and reported , hence a good (digme) tone or gunt (walk) tone. I believe a deep recovery say 9 inches plus on a dime, for instance, would be more luck than anything else using 2-tone ferrous. IMO effective useable depth is greater in conductive tone mode than using 2-tone ferrous audio mode.



Edited 1 time(s). Last edit at 02/19/2012 03:20AM by tnsharpshooter.

I learned what you discovered over three years ago while relic hunting.I got a faint lead type hit and dug a deep plug with my relic shovel.Nothing in the hole so passed coil over plug and got a iron grunt.Shaved a few inches off plug and then got a high tone.Target was a small buck shot.Started doing some test garden testing after that and learned the E-Trac does not have near as much ID depth in TTF.
I have dug a lot of CW relics that were a mixed low and high tone at decent depths once I learned the limitations of TTF.

Ive tried TTF, out in a corn/soybean/cotton field. Never found any coins,found a couple bullets,melted lead. Doesnt mean there were no coins there. Ive read on Findmall,one guy is really doing well using TTF. Im just not at a point with this machine to make a correct observation. I do know about the 17 cut off line. But, I have gone back using multi and conductive.
Have you ever experimented with two tone conductive??
Thanks for sharing,
John

He hunts mostly plowed/disced farm fields where depth is not as much of an issue I dare say.

I actually realized this on day one last July when I got my first minelab etrac. I posted the info maybe thinking some of the beginner users of etrac would read and it may help them. There are some on other forums who give this TTF advice to new users. The muli tone conductive operation is to me what sets the etrac apart from other brands of detectors in addition to deeper TID. It will wake you up so to speak when over silver. I have a V3i whites and it's just plain boring to hunt to use with its tones. I almost fall asleep evey time I use it. And to me it's not as good at locking onto the deeper coins. I believe one can actually hunt faster for deep coins with etrac versus V3i.

TTF tone break at 17 is missing good targets if you ignore low tones...

After realizing TTF was not cutting it, I now use "OTF".... Set at ONE tone and black out line 28 through 35 (deep off, fast on, manual high as feasible for the spot, low number noise cancel).

Lines 27 and up all sound off with tone, below that nulls. Dig all good tones... Boring? Doesn't bother me a bit.

Have a couple others I use too, but OTF is "go to" first.

Yeah, this has been brought up regarding deeper targets as their Fe numbers often drop. In my soil they constantly drop to the 20-24 level. I think the next E-Trac DEFINITELY needs an adjustable TTF Fe number with intelligence, e.g. - From 17 to 24 on targets that are at the halfway point on the depth meter or deeper.

I still think TTF serves an important role for re-hunting iron laden spots a second time when depth isn't #1. That said, I rarely use it. When the iron is heavy and I get nulls, I just slow down till the null goes away - that might be extremely slow, a crawl. I have compared signals I get in iron in discriminate with TTF and 95 percent of the time, discriminate sounds better.

Albert

Another good (read: 'educational') thread.

Initially got my breakin from a Explorer Guru way back when on the XS. He was so good heck one of Minelabs top guys attended our local hunt and was so impressed at his knowledge was asking him questions and even stayed overnight and hunted locally with this fella the next day..He hunted in conductive and kept it simple and I followed and
learning period was short. Why fix what aint broke is my motto so never hunted in ferrous so can't offer any opinions except perhaps whatever works and switching back and forth is an option I would not recommend.

Unfortunately Mitch was in his 30's at the time and had a great webpage but he left the hobby and so did his webpage and now understand he is a PC Guru of sorts. Indeed the hobby lost an excellent Explorer user and Treasureport vanished when Mitch left the hobby but I was lucky to have been mentored by him and enjoyed his company and expertise on many hunts...

This is an OUTSTANDING thread, IMO. tnsharpshooter, your observations and conclusions match my experience perfectly. One thing I will say -- while Explorer/E-Trac FE numbers will start increasing with depth (beyond 5-6", as you say, is just about right, in my soil), I would think this is most true in at LEAST slightly-mineralized soil, or in areas with alot of iron/rust. In very mild ground, I'd think the FBS units might hold better FE numbers to deeper depths, but not sure (since I don't hunt that kind of soil). Bottom line, with any appreciable amount of iron in the soil, the increasing FE numbers is a signature response on FBS units, and so TTF will likely be a more limited "effective" depth mode, than conductive mode (conductive being deeper -- as these machines do a nice job of holding good CO numbers with depth, even after the FE numbers start to fall off).

This, to me, is where a significant "learning plateau" occurs for FBS users -- and that is, when you realize that FE numbers will start increasing with depth, but the CO number is key. I also think this is one of THE BIGGEST advantages of FBS technology...I find it MORE than coincidental that FE numbers start rising at the same depth, in my soil, that single-frequency detectors ALSO start losing ID ability (VDI numbers decreasing). Effectively, it seems that Minelab has "moved" the "deterioration of target ID accuracy with depth" to the "FE" side of things, leaving the CO number with a high degree of accuracy with depth. Again, don't know the technicalities of this, but this is my observation after much testing with different units...

Steve

The "Conf" LCD bar-graph on the F75 does (nearly) the same thing..... in tangential fashion.