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Understanding the sounds from your detector

Rudy

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Jan 10, 2006
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Beaumont, CA
Here are some general rules of thumb for the sounds your detector makes in discriminate and all-metal (VCO pinpointing mode).
Although I write this article from an MXT perspective, this post should more or less also apply to many other detectors with modulated audio.

If my memory serves me, I believe many of these guidelines where originally posted by that Master Jedi Detectorist, Monte :).
Who has kindly shared his detecting experience with many through the years.


1. When you get a loud signal in discriminate mode and the pinpoint signal is loud--?
It is usually a large target near the surface.

2. If you get a loud signal in discriminate mode and a much weaker signal when pinpointing--?
It is usually a large target deeper.

3. If you get a good signal in discriminate mode and an extremely weak signal when pinpointing --?
It is usually a tiny target or a very deep coin size target.
Also some hot rocks and coal burnt items mimic this same sound (a little practice in this area helps).

4. If you get a good signal in discriminate mode and a clear pinpoint signal (average sound)--?
Then dig. This is usually a coin size item at average depth.
This is what many of us train their ears to.

5. If you get a weak signal in discriminate mode and also a weak pinpoint--?
This is the "cream of the crop signal" for deep target hunters.
Unfortunately some small shallow objects also mimic this sound.
Take out 3" to 4" of dirt and if the signal is still weak it is probably a deep target.
Pay close attention to those soft signals (also called "whispers" by many).

6. One way signals--these sound good on the first sweep in discriminate mode (in one direction but not in the other --backsweep, etc.).--?
When pinpointing you may get an extremely loud pinpoint and write it off as trash--DON'T!---Many times it is a good target next to a piece of trash.
Dig out the trash and look for the good target.
Experiment with some of these targets to see how your detector reacts.

7. Semi broken signals-- On the first sweep in discriminate mode you get a signal that tries to punch through the discrimination setting (usually a half to 3/4 signal).--?
This occurs in places of EXTREME trash. Swinging the coil at different angles and sweep speeds can help isolate the signal and gives you a better idea whether to dig or not.

In these cases pinpoint doesn't give you much information because of the multiple targets in the ground (trash around the good target).
Beginners have a tough time with these signals and the only real way to learn them is to PRACTICE with your detector.This is where a veteran with an inexpensive detector can clean up vs. a rookie with a new high dollar detector.

There are a lot of other things that the audio beeps can tell you. However, the specific detector being used has a lot of bearing on just how "rich" in information that beep contains. I think the old analog type detectors provided more information of this kind than the newer digital everything ones and the detectors without modulated audio take away some information as well.

On the MXT, I can usually tell by the sound level ramp up/down and width if the target is small (coin size), or a larger piece of trash. A crackly beep is usually an indication of wadded aluminum foil (it could also, under the right conditions, be a target being partiatlly discriminated). Sometimes a pulltab will produce a double beep, and so on. The non-motion all metal mode can also help you "size" the target and the VCO volume, combined with the indicated depth, can help you figure out if you really found a silver dollar or half, or if it is a crushed soda can.

Also, when you put the loop to the side of the target to go into pin poin mode, if rather than quiet you get a low level of the VCO sound before you are even close to the target, it is usually an indication of a ferrous target. It could also mean that the ground balance is way off.

You have to learn your detector's language to get the best out of it so give it time!
 
Rudy,

Thanks for this post! It is extremely helpful to newbie like myself.

Sean
 
Excellent post. I appreciate this very much. Those of us w/o dispalys are constantly trying to make some sense of the audio. My progress has been very slow, but what little I have learned seems to jive with this post.

I would say this information relates to my tesoro cibola quite well. It sounds like the weak tone in both modes is the universal tone we are all looking for. You know, the one that doesn't go away once you swing over it.

Aaron
 
You are welcome Sean and Aaron. :)

There is a wealth of info in the audio. Alas, the audio of most of the new digital detectors is not as rich with information as that of the old analog units, but the audio -not the TID display, should become one's primary source of target information.
 
Hey Rudy,

I often come back to your post, it is extremely helpful. I have one question, when you compare the sound in discriminate mode and then when you are pinpointing, are you switching to all metal to pinpoint? If no, why would the sound change between the two?

Thanks,
Sean
 
Hey Rudy,

I often come back to your post, it is extremely helpful. I have one question, when you compare the sound in discriminate mode and then when you are pinpointing, are you switching to all metal to pinpoint? If no, why would the sound change between the two?

Thanks,
Sean

Thanks for letting me know you appreciate the post. ;)

With regards to your question, on the detector I based the post on (the MXT), the pin point mode is a true all-metal non-motion mode and the sound is produced by a Voltage Controlled Oscillator (VCO). The pitch and intensity of the sound is based on the target size and depth/distance from the coil.

Hope that answered your question.
 
Thanks for letting me know you appreciate the post. ;)

With regards to your question, on the detector I based the post on (the MXT), the pin point mode is a true all-metal non-motion mode and the sound is produced by a Voltage Controlled Oscillator (VCO). The pitch and intensity of the sound is based on the target size and depth/distance from the coil.

Hope that answered your question.

Thanks Rudy, that answered my question! I have a Silver Umax which does not have a pinpoint button so... I often switch back and forth between discriminate and all metal once I have locked onto a target to try to get a better location.

Sean
 
Hello Rudy,
Thanks for the post. Good help. Reduced the learning curve a bit :yes: Cheaha bill
 
OK help me out here

I just got an MXT my first detector in more than 30 years ( I got a 20 something radio shack when I was 11 or 12) I bought the best detector I could afford with out the wife having a fit. I have dug a pound of aluminium and foil. I find your information right on track to what I have dug. By my count you can see what I am finding at a 55 year old school with my experience any more help?
 
My question deals with tone ID and tone volume. If both are on doesn't all targets reach the earphones at the same volume? Thereby making it impossible to determine depth, or a whisper or weak signal in discriminate mode? I generally operate with tone ID on with a weak threshold and high target volume, and become somewhat confused when others talk of the "weak signal" or "whisper". Am I missing something?
 
My question deals with tone ID and tone volume. If both are on doesn't all targets reach the earphones at the same volume? Thereby making it impossible to determine depth, or a whisper or weak signal in discriminate mode? I generally operate with tone ID on with a weak threshold and high target volume, and become somewhat confused when others talk of the "weak signal" or "whisper". Am I missing something?

Don't know what detector you are using, so I'll try to answer you as best I can without getting into specifics.

Tone ID is an audio alternative to a VDI number or TID. It adds no additional information. The computer inside the detector allocates an audio tone frequency to a range of VDI numbers. It does save having to constantly look at the LCD display to see how conductive the target is, but it is just an audio version of the same information.

With regards to volume, the term White's uses is "audio modulation". The audio signal volume is proportional to the signal strength. So, assuming a coin sized target, the deeper it is, the lower the resultant audio signal volume.

Many detectors do not have audio modulation at all, such as the Prizm line. Their beeps are at full volume. On other detectors, the audio modulation may be programmable (On/OFF), or selecting other features such as Tone ID may cause audio modulation to turn off.

If the detector does not have audio modulation, or it is off, then there are no whisper signals.
 
Great info Rudy, again and again. Always is great when I learn something.
waytogo.gif
 
great article!...

it sure seems like it is correct for the gti 2500 as well!...

i need to print this one and start memorizing it!


i suspect that the gti 2500 bi-level has something to do with all of this too.

i put in an query to [email protected] about their bi-level audio feature along with a report of a typo in their 2500 manual regarding manual ground balancing. hopefuly pointing out the typo will get their attention enough to answer my question about gti 2500 with bi-level audio function on.:yes:

no one seems to know what that bi-level function is about.


-zander
 
Weird. I've just read this after hunting for the past week and have picked up on many of the things you pointed out here, while others are new to me. I'm really trying to learn the sounds of the umax in hopes of being able to tell accurately what may be under my toes.

I have dug so much trash in the past week!
 
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