Iron and more Iron

[Anonymous]

My interest in how to detect in iron was ignited by reading the patents for detectors. It seems that there is a common idea that 90% of all refined metals in the soil are iron. I was concentrating more on different type of nonferrous trash metals that litter the parks but started to take a second look at iron. I started to use IM-16 and an iron mask setting on the Smart Screen to compare readings, nulls, and how they corresponded to how much iron was in the soil. I was amazed at the amount of iron in the soil at many sites and think I found the following.
Most nulls in the threshold when using threshold discrimination was not caused by soil minerals, where the Explorer is concerned, but is caused by iron. I seldom found an indication that it was soil minerals but almost always could find iron in the soil that when removed would restore the threshold. A piece of iron the size of half a normal sized horseshoe could mask and area about the size of a 50 gallon trash can lid. Some sites have an average of 5 to 7 hits on iron per sweep. Masking by iron depends on the relationship to a good target as to how much it masked the good target. That seems obvious but iron below a target depending on size will not cause the same masking as iron of the same size above the target as far as depth is concerned. The problem is compounded by lighter surface alloys of aluminum trash such as bits of soda cans, tabs, and the like.
I am still finding what iron will do but came to the conclusion that iron is the primary problem and not depth of detection. In clean ground I have never had any problem with plenty of depth even with the 8

 

[Anonymous]

I think you are right iron being the main problem
not minerals. I am thinkig that the double D coils
might be alot of the problem you get great ground coverage but since the hot strip runs from front to back and remains the same down to full detection depth its picking up every thing that is in the
ground from the tip of the coil to the back.
My wife has gti 2500 and with the consentric
coil it will pick up coins if there is iron on all
four sides where with the double d the iron can only
be to the left or wright of the hot strip. the
consentric coil gets smaller as it goes down into the
ground as i am sure every one knows already.
but even though we loose coverage it might acually
make it less prone to iron signals.

 

[Anonymous]

I have always like the concentric coils for the very reasons you state. I have never used one on the Explorer so don't know about the noise. From my understanding of the operation of the detector as explained in the patents there should be almost no problems with minerals. The pulse induction design is great but they all are sensitive to iron. Most of the really hot detector seem to be more sensitive to iron. The first real deep detecting TR I used was a Fisher and to this day even their VLF is sensitive to iron. I have used many many Garrett detectors over the last 40 years. They made the best BFO in my opinion that has been produced. Great detector and well designed but it took a lot of getting use to if you wanted the same depth as a TR. A deep coin would only give a whisper of a few beats of change so you really had to listen for deep coins. I pulled thousands of coins out of the ground with Whites, Garrett and Fisher detectors. They make a very good machine and I understand why a lot of people prefer them. I am really happy with my Explorer and DFX and have a Sovereign for the "just in case" machine. It has been a few years now since I have used a 2500 but like them and think they are a good detector.
HH, Cody

 

[Anonymous]

Cody,I've been trying out your trash-iron program,that you mentioned awhile back,now that our ground has thawed-out some,by opening up the fe-coin area and switching to ferrus-tones,I like it!Gives me a good threshold,and with fast on,deep off I went back over some problem ground that I used to have major nulling issues with pulled out some nice stuff! Iron sounds like iron and silver&gold next to iron sounds well I don't have to tell ya that one!!Thank-you!HH.

 

[Anonymous]

little confused,does IM-16 block more ferrous or IM_5 lets say.Kinda confused as to one end from the other??thanks scott.

 

[Anonymous]

I am glad to hear that as I keep working with the program and did a lot of hunting with it today. I am trying different settings and ways to make it work depending on how much iron there is to deal with.
You hit on the advantages exactly, iron sounds like iron and you can pick through and pull out the good targets. The more iron there is the more time it takes but that is better than walking over good targets and not knowing there is anything there but silence. My son and I found some good targets today with the program that I think we would have walked right over due to all the iron nulls with no threshold to guide us.
HH, Cody

 

[Anonymous]

<STRONG>IM-16 accepts all ferrous metals and IM 0 rejects all ferrous metals which is mostly some form of iron.</STRONG>
If we want to block most ferrous iron but accept just very little we might set the mask to IM-1. If we want accept a little more ferrous metals then we would drop the mask to IM-2, to accept a little more ferrous by going to IM-3 and when we get down to IM-16 we are accepting all ferrous metals <span style="background-color:#ffff00;">when Iron Mask is ON.</span> If iron mask is off then we are using the pattern on the SmartScreen.
We unmask by accepting more ferrous metals to prevent null of the threshold caused by the iron or we mask by rejecting more iron but have more null of threshold as we pass the coil over iron.
HH, Cody

 

[Anonymous]

Cody--- You mention the use of your 8" coil; Can you give a comparison in the iron world with a 5" coil .(if you have one) Or do you recommend a 5" for trashey soils . thanks ahead Fred D. Central N.Y.

 

[Anonymous]

I have used smaller coils on my DFX but not the Explorer and really like them in very heavy trash. The fewer targets we get under the coil at any give point in time the better it is anytime. The coils now days have a very large electromagnetic footprint so even a 5" covers a lot of ground in a single sweep. So the bottom line is I definite like the smaller coils in heavy trash. The 5 and 3" are both very good coils in my opinion.
HH, Cody

 

[Anonymous]

My opinion that if we want to hunt with concentric coil then 5in DD will be almost the same as 8in concentric because it has almost same small "hot spot" at 8in depth as concentric and less dependent to nearby targets. I made air test with Fisher 1266 ( 8in concentric ) comparing to Ex2 (5in dd sens28 ) both showed equal depth. Also I think that DD has more priority because of slower sweep speed where VLF just fly over good co-located targets lacking without good speed.
Some months ago I also suggested, useing the switch for 10 and 5in coils, to use the latter ( mounted below the battery as X probe, on the small handle ) as the pinpointer at min sensitivity,a bit heavy but cheaper, deeper and more practical for some other reasons.
To compare 8in and 10in for Ex2 I was told by some dealers that 10in will be the same as 8in just reduce the sensitivity.
Also to my mind it is not a huge problem to have 5 iron hits per sweep, so that means that if we have one between them non-iron, it will be out.
HH Dok-Atn

 

[Anonymous]

I think we are going to see the next generation of detectors as not needing motion to discriminate and ground balance. Think of the Explorer or DFX as a detector that can be moved very slowly just as we could the old TR detectors. If we could lay the coil on the ground and move very slowly then a lot of problems would be resolved.
HH, Cody
HH, Cody

 

[Anonymous]

I think by that time or after 20-40 years nothing interesting will be in the groung. Good time for us now. <img src="/metal/html/smile.gif" border=0 width=15 height=15 alt=""> <img src="/metal/html/smile.gif" border=0 width=15 height=15 alt=""> <img src="/metal/html/smile.gif" border=0 width=15 height=15 alt="">