To disc or run IM comments plese

[npaisnel]

Just starting this thresd to see what other people do, what their ideas on this are.

I hunted a part of the field the other day, where I have found a few coins in the past. Small field of about 1.5 acres.
I did a small section about 20 m x 50 the other afternoon. Found and dug about 60 'good' sounding targets. An awful lot of crushed up foil, that gives a good soild clean sounding signel, a few bits of brass/copper pipes and a few modern (1800's) to present day) coins. This was with the machine set up on IM -12.
You get alot of signals that you have to thing about, and only dig the good sounding ones.

Yesterday i went back with a very heavy disrcim pattern, made from all the coins I had collected over the last year or so. Much tighter pattern than the built in coin pattern. Any sounds that were clipped by the discrim (or poor signals that jumped around a lot ) I opened up back to IM to check, and usually they were rusted Iron so I did not dig.

Now on this second day, I still picked up a lot of this crushed up foil/aluminium, that fell within the open band on the descrim pattern. You cant disc it out, as each piece seems to have different properties as they are all random shapes.
I found slightly more targets that i dug (about 80 or so). Still 40 of them were this crushed foil, but the rest were coins, buttons, interesting bits of brass fittings etc.
I covered a lot more area, but always the nagging feeling in the back of my mind that I could be missing good stuff that is being disced out. I know from the day before this probably not true, as I actually found less good 'keepers' the day before, but all those nulls you hear....you just wonder what they are.

I know we must trust the electronics but....you never can be sure....can you?
Overall I had a more satisifying day, covered more ground before the field is planted again, and have a chance of finishing the field before the tractors move back in.

Other setting were
Fast response.
Auto 26
Conductivity sounds
standard 10.5 DD coil.

So..
no question really, just an observation, and comments as to what othere do welcome.

Neil

 

[Dan-Pa.]

Why not fast and deep or just deep??? Depends on your conditions.
Many of our experienced fellows run sensitivty as high as they can while keeping a stable unit..
Of course ferrous or Conduct is a matter of choice along with which coil you use.
Unfortunately many pieces of junk which you have been digging mimic good targets but a trained ear can detect audio variances.
Most of our more succesful hunter run it wide open at -16 and hear all
again its a noisy mode and a keen sense of hearing comes into play.
Just a few comments on your post and with time in the field you will learn the unit and its sounds better and that comes with experience...

 

[npaisnel]

For the past year, I had pretty much always run wide open, almost, IM -12 or thereabouts. Probably got about 300 hours or more logged on the machine now between beach and fields, a mix between coins and battle relics from 1400's to WWII. Trouble with looking for random shaped unknown relics, they can sound just like scrap till you dig them up!!

Where I have been recently are regularly ploughed fields down to about 14 inches, so going for the depth is not a real requirement. If we dont see it on the surface this year, the plough will pull it to the surface next year!

I had been using a mix of auto and manual, but went with auto this time for an easy life. If I went above about 26 in manual there was a lot of random noise, so and auto setting was nice and easy.

Used conductivity on sounds this time as the disc pattern was very tall with very little width on the screen.

This is the first time I have really been using any discrimination, and it certainly made the day easier, and found more good keepers.s between good and scrap

I am still keeping all the old scrap that I find for the moment, to try and help in learning the sound difference.

No discrim
[attachment 25345 IMG_1449.JPG]
36 good finds 43 scrap

Day two with disc patttern
[attachment 25346 IMG_1451.JPG]
40 good 46 scrap

On day two, covered a greater area, for a smiliar number of finds so probably are missing things that I may have got running wide open and not digging any less scrap.

Guess I'll have to keep trying to learn those sounds, but will random relics have nice sounds ??? i think not.

Cheers for your comments,

Neil

 

[James N.D.]

Try running Iron Mask -16 and use ferrous tones next time. Most of the Iron will give a low tone and you will get high tones if you get anything that is other than Iron. You will get the occasional nail but you will find coins next to iron that would otherwise be masked and be a null if you run in conduct tones. You will hear everything in the ground and a little practice could get you on track to finding more good targets on your next trip out. Run fast also.

 

[npaisnel]

I had been using ferrous sounds when wide open, but never as far as -16. As I had been running -12 or so a lot previously thought I would try a heavy pattern to see what happens. Over the past year have tried large combo of settings, but very little discrim.Wanted to give it a go to see. It certainly makes the day easier, less thought involved!

I was hoping to have seen a large difference in the good/junk split with/without the disc pattern, but no. To have the facility to blank out junk but then not use it seems a waste.

What I now really need to do is go over the same area again at-16 and see if I have left much. I can see the field from home but have to work this morning. Ambulance flight from the islands here over to mainland England,but fogged in at moment, so sitting at airport now killing time.

 

[GraveDiggerMax-VaBch-Va]

n/t

 

[npaisnel]

Would cutting back the sens to 18 reduce the amount of trash I pick up? I cant see or understand why that would make much difference to how much trash I pick up.
Most of the trash was fairly bigish bits fairly shallow, (surface to 6-8 inches) while a lot of the coin signals have been weaker. If I went lower on the sensitivity would I just not loose the signals from the smaller coins and end up with a greater proportion of trash?

 

[James N.D.]

What GraveDiggerMax is trying to tell you is that when you run your sensitivity too high, you are not getting the maximum performance out of the detector like you thought you were, especially in Iron Infested Areas like the one you are hunting. Let me put it this way so you understand better of what he is telling you. If you are driving in a snowstorm in the dark and you go and put your High Beams on, you loose distance for the visibility you are trying to achieve. You will decrease the amount of visibility when you do this because of the amount of snow falling. When you go back to normal beams you increase visibility so you can see farther down the road. It is the same thing when you detect in Iron Infested Areas. You have to run less sensitivity because if you don't the detector will not respond fast enough to tell you that there is an item you are passing over. I hope this is what GraveDiggerMax is trying to tell you and if not he will respond back and tell you.

 

[npaisnel]

Ok, yes. I do already understand that, but most of the trash in this area is not particularly high in iron content. In the pics, all that scrap is givivng signals right in the same area where the coins themselves register.
Last night I sat at home and tried id ing the finds by ear. Set IM -16 and passed scrap and coins over the coil. Was hoping to hear coins giving cleaner tones than the scrap, but it seems totally random.
I might have to put you guys to the test by recording the sounds, posting them and seeing if you can guess scrap or coin