Man you know I really cannot tell you exactly how threshold works but it has to do with setting the unit so it will respond correctly while searching in the disc mode. If there is not enough(threshold) it will not be as responsive to smaller targets but it will still ring out on bigger ones. And I do not care what you have read about sensitivity, I always ran mine as high as I could without it making false signals. Alot of guys will tell you that it does not matter and the sens knobs do not have to be turned up all the way to find dimes and stuff. It makes a difference to me, so be sure you turn that sucker up on sensitivity!!! There is kind of a way similar to super tuning it and that will be turning up the threshold all the way and searching in disc mode. It kind of makes your detector run on the hot side. In other words it will be sensitive to deeper stuff. I myself do not reccomend this setting. The best way to get the most depth out of your machine is to run it in all metal, with the threshold audible, then when you have a good signal go and put it in the disc mode. If it is still giving a signal or if the signal is fainter I would go ahead and dig anyway. You just never know what is there.
As far as the deeper coins go it would ring out a good tone but it will be fainter or less audible while swinging in both directions, with headphones you would really be able to see what I am talking about. Also as you mentioned before about a coin being on edge, how it reads solid swinging one direction then sputter on the other direction, the same goes with deep coins too, it just is not as loud. The best way I can describe what you need to hear is just take out a coin and put it on the ground and swing your detector over it slowly getting higher listening to how the machine responds to the higher you go with the coil. Obviously it will eventually fade out and you may not hear it at all without a pair of headphones, but you will be surprised that you can still hear it with headphones on.
I started out detecting with my brother back in the early eighties, since I was the little brother I was his digger. When I turned 21 or 22 I moved to TN. I got my own detector and started looking for myself. It took me about 10 years to find my first silver coin but it was my favorite when I did find it, a mercury dime 1944!!! Wow I could not believe it, then about 2 or so weeks later I got another one 1917 and a few more. Tell you the truth I dug countless wheat pennies and clad, boy scout badges, toy sheriffs badges and so on but no silver for 10 years. I hated it too, it really discouraged me. I would sell the unit I was using and buy another name brand one. Just because I thought it was the machine. Heck I knew how to run one too, I thought. Then my brother told me what I said in a previous paragraph to you about back then they would get down and find that old dime or quarter they dropped. It finally made sense to me so I just kept digging wheats and all until that day the merc popped out. So do not get frustrated into thinking the unit sucks or is not as good as a minelab or fisher or whatever. The key to detecting is knowing your machine and take time to learn that baby. That tesoro is a great unit and like I said I still wished I had mine. I am fixing to buy another tesoro from my brother (eldorado) it has a ground balance but otherwise just like the conquistador.
Let me tell you, when you finally come across a silver dime or something silver or an old civil war bullet, there will be a good solid sharp tone, it will be different from how even a wheat penny sounds and you will learn that sound like I did. It (tesoro detectors) are hot on silver, brass and lead big time. You can really tell, once you have found some ole bullets and silver coins, what it just might be before you dig, even though it only has one tone.
About the uMAx coils, If your hunting old houses and all or ever go to a park I would get the 4" concentretic coil for sure. There is one on ebay at the moment right now that ends in less than 3 days at 36.00 right now. If you have an account with ebay I would be all over that like a duck on a june bug!!! I would get that one first. I would consider the bigfoot one but tell you the truth if your not hunting in big open areas I would just stick with the 8" that came with your unit and that 4" one for sure in trashy areas.
As far as nature goes and detecting in the summer months, I am a "chigger magnet!!" Man all I have to do is just walk around my house one time or weed the ditch and they are on me like stink on $h!t and I hate it so much cause I have some places to check out right now too!!! Even off and deet and stuff like that doesn't do the trick for me either, that is why I go in the winter, fall and spring!!! I do not know what part of the country you live in but take my word and ask anyone else on here, moist ground lets you detect deeper objects. Try it next time it rains in your area. Hey as far as getting to brushy areas I used to take a weedeater or trimmer with me and fire that baby up around old house sites and buildings and all for about 15-20 minutes to get rid of that tall stuff and get my coil close to the ground. I am sure some of the owners would not mind you doing that either. Where do you live anyhow? Just curious hope you do not mind me asking, Tim
I found this boo-boo early on with a friend's Conquistador that had a factory preset GB that was not functional with a 10X12 concentric coil.
