Find's Treasure Forums
Welcome to Find's Treasure Forums, Guests!
You are viewing this forums as a guest which limits you to read only status.
Only registered members may post stories, questions, classifieds, reply to other posts, contact other members using built in messaging and use many other features found on these forums.
Why not register and join us today? It's free! (We don't share your email addresses with anyone.) We keep email addresses of our users to protect them and others from bad people posting things they shouldn't.
Click here to register!
Need Support Help?
Cannot log in?, click here to have new password emailed to you
Just out of curiosity?
- Thread starter crazyman
- Start date
Art (NWOH)
New member
BBS transmits more than 17 frequencies......
The output is a multiple frequency square wave, and if I remember right, a square wave is composed of an infinite number of odd harmonics. So really a huge number of frequencies are involved. How many are really of significant amplitude to be useful...I don't know.
I am a little rusty on my electronics, so I could be wrong. It could be even harmonics for a square wave and odd harmonics for a triangle wave. Don't much matter.
From what I understand, BBS needs to look at the ground with multiple frequencies to determine from the response as to what is ground and what is metal. How many frequencies are looked at I don't know, but am sure that it will at least use several if not all of the 17 that are listed by Minelab.
HH
The output is a multiple frequency square wave, and if I remember right, a square wave is composed of an infinite number of odd harmonics. So really a huge number of frequencies are involved. How many are really of significant amplitude to be useful...I don't know.
I am a little rusty on my electronics, so I could be wrong. It could be even harmonics for a square wave and odd harmonics for a triangle wave. Don't much matter.
From what I understand, BBS needs to look at the ground with multiple frequencies to determine from the response as to what is ground and what is metal. How many frequencies are looked at I don't know, but am sure that it will at least use several if not all of the 17 that are listed by Minelab.
HH
Critterhunter
New member
I think also that the noise band is just changing what frequencies the machine is looking at from the signal, avoiding the noisy ones the other channel was having problems with. I don't think it shifts the TX frequencies at all but rather just changes which ones it looks at, but I could be wrong. I've heard of Explorer guys who say that certain bands selected during noise cancel by the machine can make it more or less prone to certain target metals. I've heard some claim getting targets that the other bands didn't hit on hard, but haven't read any solid proof of this myself.
Regardless of how the noise band works on the GT (either by shifting the TX frequency or more likely by shifting what it's paying attention to) one might produce slightly better depth on certain metals over the other based on where those bands are....in theory. Most know low frequencies in say the 3khz range or so tend to hit harder on silver and copper, while stuff in the 12 to 22khz range or so tends to hit harder on gold and other low conductivity targets. Higher frequencies are more prone to reflecting off ground minerals (though certain minerals can present specific frequencies with problems regardless of how low or high they are), and so many prefer a low frequency for getting as deep and hitting as hard as possible on silver and copper coins. All just general rules of thumbs and I'm sure there are many exceptions. I'd like to know which frequencies the two bands on the GT's noise cancel are using and run some tests on depth of various metals with both of them. Perhaps that's why noise band 1 makes nickles read a little higher- Maybe it's using or paying attention to higher frequencies more and so his hitting harder on nickles, raising the VDI a little via the conductivity at that frequency?
Regardless of how the noise band works on the GT (either by shifting the TX frequency or more likely by shifting what it's paying attention to) one might produce slightly better depth on certain metals over the other based on where those bands are....in theory. Most know low frequencies in say the 3khz range or so tend to hit harder on silver and copper, while stuff in the 12 to 22khz range or so tends to hit harder on gold and other low conductivity targets. Higher frequencies are more prone to reflecting off ground minerals (though certain minerals can present specific frequencies with problems regardless of how low or high they are), and so many prefer a low frequency for getting as deep and hitting as hard as possible on silver and copper coins. All just general rules of thumbs and I'm sure there are many exceptions. I'd like to know which frequencies the two bands on the GT's noise cancel are using and run some tests on depth of various metals with both of them. Perhaps that's why noise band 1 makes nickles read a little higher- Maybe it's using or paying attention to higher frequencies more and so his hitting harder on nickles, raising the VDI a little via the conductivity at that frequency?
Neil
Well-known member
Crazyman Ive no idea but whatever they do it sure gives good ID on shallow and deep stuff, runs smooth most anywheres and Im not making adjustments to often to maximize performance. I honestly wish all manufacturers used this technology, Id love to see Tesoro make a 3 pounder that was FBS/BBS that used one 9 volt battery, like their umax models
JOHNMARKHAM
New member
nice reading..
interesting
thanks
john
interesting
thanks
john