Jump to content

Low Weighted Multi Vs 5/10 Khz To Avoid Tiny Targets


Recommended Posts

Hi Argyris,

after seeing the size of your aluminum in the photos I can understand why those melted pieces of aluminum are reading where they are. They are fairly thick and compact and most are coin sized which should put them in the 10 to 18 range easily. Like Chase, I hunt old mining sites where there have been miners continuously for 150 years (which is nothing compared to your target's ages) and there is 70 years worth of melted aluminum near every campsite. Those aluminum blobs do sound hollow or spread out in detect mode as if they sound bigger than they are and they do not have well defined edges to my ears like coins and rings do, or in my case.....gold nuggets that are often 1 mm in size or less. In pinpoint mode they should have a really loud high pitched whine which again will most likely seem larger than their actual size. Maybe your aluminum is different but listening for those differences is worth a try.

Jeff

  • Like 2
Link to comment
Share on other sites


Yes Jeff, need to train my ears for sure....there's no shortcut to the learning curve...just some "tools" to help me some in my beggining (my cheat sheet from all members' tips in this topic).

I'm waiting for the rainy days to pass and will go out hunting again. Till then, I'll continue my bench testing and try all tips given to gain some first experience! 

In the end of the day, I really enjoy it and don't expect miracles...! Hunting time will teach me what I need to know afterall!

  • Like 1
Link to comment
Share on other sites

Guys, check this out:

I just finished a bench test with different targets to 1) see the VDI stability from all directions vs target's shape, and 2) implement the 5 khz test method that Chase mentioned to see if I get something usefull...

Well....regarding test #1 (vdi stability from different swing directions vs target's shape): no new info here...all round objects (rings/coins) have extreme vdi stability from all directions - one number rock steady vdi period. The aluminum nuggets of my picture showed some minimum vdi directional instability but not much to depend on it (only +/-1 or +/-2 points divergance when changing swing direction so no real clues). However large misshaped can slaw or other misshaped aluminum showed a definite change in vdi from different swing directions so I'll keep this clue.

Now..the most interesting part....VDI test with 5 khz vs Beach 1 Multi...check the info below:

  Beach 1 5 khz
Silver Dime 26 27
Silver old coin 26 26
Silver pendant 17 18
Copper coin 21 22
Old Nickel coin with hole in the middle 20 21
Thin junk ring 16 17
Gold band 13 14
Small aluminum pull ring 12 12
Aluminum nugget 1 13 21
Aluminum nugget 2 20 27
Aluminum nugget 3 18 21
Aluminum nugget 4 20 28
Aluminum nugget 5 16 19
Aluminum nugget 6 20 26
Aluminum nugget 7 22 27

*The result above when using 5 khz, was already stated as a method to identify bottle caps: change from multi to 5 khz and bottlecap's vdi should jump really high (I tried that to, and indeed they jump at 30s when applying 5 khz...but beach 1 mode with F2 setting @6 already takes care of them anyway)

But I also see a major VDI increase for the majority of these aluminum nuggets when changing from multi to 5 khz....their VDI jumps pretty higher....furthermore, the larger the nugget, the more VDI increase/divergance in 5 khz mode vs multi observed.....All other targets (coins, rings etc even low conductors like old nickel coin or aluminum pull ring) didn't jump in higher vdis when tested with 5 khz but stayed almost the same vdi wise.....strange...... and wonder if I could take avantage of this VDI increase in undesired targets like the aluminum nuggets of my beach...what do you think..??? I really believe that I'm missing something here...can't be so obvious....and this was only an air test after all so things could be way different in the ground....but I thought it was something worth sharing with you..

  • Like 2
Link to comment
Share on other sites

Hi Argyris.I find those  aluminum nuggets in lake Ontario.They     range in all sizes.They so sound good  .  I can   tell the small ones by sound.My parents come from Florina    area which is about as far from the sea as you can get in  Greece.My  fathers village of    Drosopagi was burnt in world war 2.Not that old  (1844-1944),but being by mount vitsi there are many gold coin  stories I heard.Cans  of gold dropped by planes in old village for  war effort.  I  heard that  German tourists came and camped by old village and when they left there was a  hole where tent was.Old soldier that buried gold and went back and got it 40 years later.

  • Like 1
Link to comment
Share on other sites

Yes mate 🙂 Many stories of small cans containing gold sovereigns that were throughn from British allies' airplanes at night, to support Greek resistance during WW2...My village in Pelloponissos has some really old history too and is my primary hunting area when in holidays or day offs (I live in Athens)...Have not found any hoard yet, but some thousand years oooold finds here are even more important than gold and taking their place in Nomismatic Museums after seeing the daylight again after so long...great history in Greece and we all try to preserve it 🙂

Regards from Greece, I too have many relatives in Canada...maybee I should visit them someday 🙂

  • Like 2
Link to comment
Share on other sites

26 minutes ago, Argyris said:

Yes mate 🙂 Many stories of small cans containing gold sovereigns that were throughn from English allies' airplanes at night, to support Greeke resistance during WW2...My village in Pelloponissos has some really old history too and is my primary hunting area when in holidays or day offs (I live in Athens)...Have not found any hoard yet, but some thousand years oooold finds here are even more important than gold and taking their place in Nomismatic Museums after seeing the daylight again after so long...great history in Greece and we all try to preserve it 🙂

Regards from Greece, I too have many relatives in Canada...maybee I should visit them someday 🙂

I am on   the   NY  side of lake.My  friends  parents and sister moved back to  Greece and  also live in Athens and are  from a   village in the Pellop. too.They have many orange and   olive trees.   Hard to top the history  of Greece.Was in Athens last in 1982 to visit my Dads second cousin.

  • Like 1
Link to comment
Share on other sites

For me, reducing the sensitivity helped the most to get used to the detector and rid of those really small targets at difficult beaches (sens at 16-18). Summertime fresh drops search = low sens, wintertime left overs search = high sens 🙂

I sometimes use 5 or 10 kHz Park 1 to distinguish Pulltabs from Euro Coins, as they change their target ID significantly, when using low single frequencies. But 98% of the time I try to stick with MF.

 

  • Like 2
Link to comment
Share on other sites

Guys, any guess on the VDI observation above? What causes this large increase in VDI of these pure aluminum nuggets when using 5 khz single freq vs low weighted multi? I know that this is a common tell-tale to ID iron containing bottlecaps when checked with 5 khz (they do jump in higher vdis)...but what about these pure iron free aluminum nuggets? Maybe it has to do with their shape irregularity and 5 khz catches that and multi doesn't..?....I don't know!

ps. As you can see, all other good targets (coins/rings)  didn't show the same vdi increase when checked with 5khz...they were +/-1 point VDI steady between multi/5khz.

In my newbie perspective, I would assume that I can use this 5 khz check method and ignore everything that shows a large VDI increase when checked with 5khz vs multi VDI....but it was just an air test so I don't feel confident enough to use it before I get some of your insights on this phenomenon and if it could indeed work in real hunting conditions...

Thanks

Link to comment
Share on other sites

Just an afterthought--I have a beach that's full of this slag too.  Run the F2 up at 8 or 9--it will knock out these complex alloys.  This is a very valuable feature that no other detector has best I know.    

cjc

  • Like 3
Link to comment
Share on other sites

5 hours ago, cjc said:

Just an afterthought--I have a beach that's full of this slag too.  Run the F2 up at 8 or 9--it will knock out these complex alloys.  This is a very valuable feature that no other detector has best I know.    

cjc

Many thanks Clive, I definetelly have to check this in iron-free areas (beach) where masking is not a risk.... I thought that iron bias would help only with iron-containing targets (eg bottle caps), but I have to try your suggestion for sure, thanks a lot! 🙂

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...