Exact explanation of "modulated audio"

[IDXMonster]

Will someone define this please?its my understanding that it makes the week signals stronger and strong signals softer,but in the same breath that doesn't make any sense that it would be that way. Hence,I'm asking the question....

 

[khouse]

Small and/or deeper targets are a softer tone. Sometimes just enough to raise the threshold hum. Shallow and/or larger targets are a stronger signal.

Some machines have a "saturated" signal that when a target is triggered it responds with a strong signal on all targets and depth.

 

[Hombre]

IDXMonster

Khouse's explanation of modulation is spot on. I suppose this question was directed to me as I was the only one that responded to your post "How deep is your IDX Pro? In my post, I mentioned that 7" deep coins were very modulated with the 6

 

[IDXMonster]

Thanks Guys. Randy,I read what you had said,I just never really knew how it worked FOR SURE. In this hobby I think there are many who ASSUME things,cuz it's what they heard once but I'm always after hard facts. I realize there is a lot to this hobby that is a big "grey area" and sometimes hard and fast info is hard to come by. I want to make sure I have my machine operation down to a science,and I just thought that a lot of machines signaled with the same strength no matter how deep the target was. Being as the IDX works the way it does,that is definitely a PLUS for figuring depth,but it's something I won't necessarily use much as if I get a signal,I'll dig it. That's obviously not possible everywhere but as a general rule field hunting and the like,there's gonna be a hole! Thanks for your knowledge and responses,they are invaluable in helping those of us who are always looking to get better at what we all do.

Kevin

 

[Hombre]

OK, fair enough.......... but let me ask you one thing, how did that 9" Indian head penny sound? I read in one of your posts that you found a 9" inch deep Indian head with your IDX Pro equiped with a 6

 

[skookum]

Hi,
Personally I think that this is theory and sales hype.
A coin standing on edge will give a faint signal compared to one laying flat - both at the same depth.
A small piece of gold chain will have a faint signal compared to a coarse gold chain rolled up tight - both at the same depth.
Since you don

 

[IDXMonster]

Randy-it was barely a "blip",and one of the reasons I had asked how deep the machine would go on average,because I was VERY surprised to find anything in the bottom of that hole. As I said,my buddy swore up and down that he had gone over that patch with his Garrett 1350. Now,the possibility exists that the Indian was knocked off the SIDE of the hole and wasn't that deep in the first place. However,I have been getting very surprising depth with the 6 1/2 on other things,so I didn't think twice about it at the time. I'll have to pay closer attention to things this season and report back with some numbers later.

 

[805MULEMAN]

http://thelibertarianrepublic.com/couple-discovers-10m-gold-coins-rusty-can/#axzz2uN5VlnAq

 

[Hombre]

I agree with you skookum, yeah the faint signal could be a coin on edge, I have dug a few of those. Some of the on edge coins were obvious as they gave a double beep from one direction and a solid beep at a 90 degree angle. I dug a couple of those signals carefully and observed the coin in a undisturbed vertical position. I have also dug small copper washers at a shallow depths that read as a dime on the meter and had that sweet, faint, deep sounding signal, those will fool you too. I have been at this hobby for 19 years and I am still learning, nothing is written in stone as far as I'm concerned. HH

 

[Monte]

Keith and Randy pretty much described 'Modulation' for you. As was mentioned, some smaller size targets or maybe a coin on edge will also produce a weaker audio, but that doesn't mean they are deep. If you moved those targets just a little deeper their weak response would get even weaker then disappear. That reaction, still, depicts a 'Modulated Audio' response. A weaker response from targets as the coil-to-target distance increases.

Naturally, a lot will depend upon the search coil and settings used, as well as the particular detector because there are different variables that come into play when you look at the three types of audio responses, Moderated audio, "Variable Saturation" audio, and fully Saturated audio. Not all models provide the middle choice. Two of those I use the most, my MXT All-Pro, and even the MX5, can produce the 'Variable Saturation,' based upon the Sensitivity/Gain setting.

Randy-it was barely a "blip",and one of the reasons I had asked how deep the machine would go on average,because I was VERY surprised to find anything in the bottom of that hole.

We have to factor in the variables and part of that is the ground mineralization and density/porosity we are dealing with. I seldom ever use a coil on a modified IDX Pro other than the 6

 

[IDXMonster]

Monte-thanks for your insight on this,I've read many other posts of yours including your air tests and such,invaluable info for the guy who's trying to "get it right" instead of just get it. After awhile of reading I consider Randy,Keith and yourself the authorities on these critters. It is certainly nice NOT to have to go through years of trial and error to see what works and what doesn't,although there will be some of that depending on conditions. As I stated before in another post,I will never leave the house without that 5.3 BM anymore,it would be like forgetting my wallet to me.
I also stated that the Indian was completely green,I'd imagine there was some kind of mineral reaction going on there that may have enhanced the ability of the coil to see it,but again,since I wasn't expecting to see anything way down there I didn't give it the fine attention I probably should have. I am glad I kept going till I did find something,instead of giving up on the signal and chalking the signal up to some other reason.
Now that I know the 5.3 is reliable to 7" but COULD go deeper,most everything is getting dug. And yes,when I sent one of my IDXs in for a tune up recently I even TOLD Connie that if the IDX Pro "hot rod" were available again I'd be the first guy in line. Both of mine have the ground balance mod,I just drilled the case to adjust the T-hold as I don't mess with it much.Now we Wisconsinites have to wait awhile for this arctic blast to leave,it has been a LONG winter for most of the country,in case you guys haven't noticed.

Thanks again you guys for all your help and thoughts,it certainly always brings things more into focus!

Kevin

 

[Aesop]

The best surprise would be to see white reengineer the Classic series circuitry and bring out a new-and-improved Classic. Just two models, no more, but match the versatile performance of the Classic ID and IDX Pro. Give one of them a manual GB and Threshold adjustment, duplicating a 'modified' IDX Pro.

A new IDX Pro (IDX Pro II) would be awesome! Come on, Whites!

 

[farmerboy856]

I'm with you guys on that! Just please don't cram it in the newer plastic housings! Still something about the black sl casings when i think metal detector thats the basic image that always comes to mind love the feel and looks of them. To me it has quality written all over it. I'd buy two right away one to use and one to store away so in ten years when everyone realizes what an awesome machine they are i won't end up like them on the out side looking in trying to find a nice one! Just like people have been coming to see with ids and idx pros.

 

[Aesop]