Infinium frequency questions

[Bill D. (VA)]

I'm a long-time relic hunter but a new Infinium user, so please pardon my ignorance. I know this machine can be adjusted to use one of 32 different frequencies. Assuming that the machine is stable at any frequency, is there any advantage to tune in a particular frequency (or range of frequencies) depending on what your target conductivity will be? In other words, depending on if you're looking for gold or brass, would it be best to hunt with a low, medium or high frequency? I believe as a general rule, using low frequencies helps to improve depth while high frequencies provide better sensitivity (like for small gold items). I guess what I'm getting at is would it be better to use low frequencies for relic hunting (brass/lead, etc) and high frequencies on the wet beach? Also, when adjusting the frequency, are you increasing it when turning the knob clockwise (lowest frequency on the far left)? One last comment. I saw somewhere that this machine actually has 96 distinct frequencies. If that's true, does that mean that when operating at any of the 32 positions the machine is actually transmitting 3 frequencies simultaneously? If so, would all 3 be close together, or a low/medium/high mix? Sorry for all the questions, but I'd like to be able to know exactly how this machine operates so I can take maximum advantage of the technology. Appreciate comments on any of the above topics.

 

[John-Edmonton]

That's a little too technical and out of my scope. Call Garrett and ask for Sue. Click below for the contact information:

http://www.garrett.com/contact.asp

 

[huntcav65]

n/t

 

[GoldChaser]

It is my understanding that the Infinium is always pushing 96 frequencies into the ground. The frequency adjust knob only shifts or changes those frequencies very slightly. i.e. Not enough to affect how a particular type of target responds.
Here's what Garrett emailed to me a while back:
"The transmit bandwidth of the Infinium unit is 500HZ to 150 kHZ. The Infinium has 32 channels and each channel has its own set of 96 frequencies that move inside the transmit bandwidth."

 

[dahut]

It is my understanding that the Infinium is always pushing 96 frequencies into the ground. The frequency adjust knob only shifts or changes those frequencies very slightly. i.e. Not enough to affect how a particular type of target responds.
Here's what Garrett emailed to me a while back:
"The transmit bandwidth of the Infinium unit is 500HZ to 150 kHZ. The Infinium has 32 channels and each channel has its own set of 96 frequencies that move inside the transmit bandwidth."

Im an electronics whiz and I'm here to tell you - that is some serious technology, right there. The details of that have got to be mind boggling. Im starting to think the Inifinium is worth the price.

 

[parrott]

Just my thoughts: A PI is different than a VLF...The frequency adjustment on the Infinium
is explained in the manual. It's purpose is to select the quietest and most steady positions.
There are 32 trial and error positions. So listen and adjust across the dial by tweaking the knob
and wait a few seconds before tweaking again... the object is to select the best position for the
unit to be the most steady. (This is the same as is done on the minelab PI's. To try to eliminate
outside external electrical interference.)

 

[parrott]

Due not confuse frequency with the pulse delay... The value of the Pulse delay is critical to the sensitivity and depth of a nugget... If anyone can post the minium and maximum Pulse values in uS could be of interest in setting up the Infinium.

 

[parrott]

John.. another thought... knowing the Pulse delay could help you in finding gold rings... The purity of the metal in the ring and its size, small or large, will to a degree determine the depth, sensitivity, and intial HIGH or low tone...This is good knowledge
for everyone... gold prospectors or beach hunting... You are one of the "guru's" now posting on this and the Gold Centre forum... So, most likely you can get the information regarding Pulse delay... But maybe the folks at Garrett are keeping it a secret... (for the TDI is is 10 to 25 uS). Thanks and Best Wishes...

 

[bearkat4160]

Someone asked Phil at GMC a while back but he did not give the info for some reason. We all know the Minelabs uS and the Whites as Parrot mentioned....does anyone know the Infiniums lowest pulse delay? I'm guessing it is 15 uS, from reports of it and comparing those reports to Minelab and Whites seems to have a tad more sensitivity and they are around 10 uS.

Alan

 

[parrott]

bearkat4160... I have also received a guess by a "guru" that the minimum Pulse delay of
the Garrett LS is about 15uS. However, if it is, this does not make it worse or better. But,
knowing as much as possible about any detector is very helpful (critical?) in being
knowlegeable in using that particular detector under conditions that make it the best to use
in certain (specific) areas...

Having specific knowledge of the parameters of a "do-all" such as the L(and) S(ea) Garrett
Infinium is most helpful for those who are serious gold prospectors. (The Pulse Delay may
not be as important to the mostly Sea users who mostly post on this and Phil's forum,
but then again maybe it is for those whose who seek for gold(en) rings...For them... I will only
suggest: keep the Pulse delay as low as possible and dig both the HIGH and low initually
sounding tones...).

bearkat4160: Thanks for the post... I will now assume the lowest value of the Garrett Infinium
Pulse delay is 15uS at "0" Discrimination and lowest threashold. This is fine with me; I will
use this information to my advantage... My Best to All who are reading this thread...

 

[waterjunkie]

I found this site that may helpful. Good luck

http://www.akmining.com/mine/garrett_infinium_tips.htm

 

[Adrian SS]

HI Bill D,
With the Infinium it makes no difference what frequency you use, discrimination and sensitivity to all metals remains the same.
It is the nature of the beast.

Adrian SS

 

[Adrian SS]

One other small point.
During frequency adjustment, turning the disc control towards iron check DECREASES the number of transmitted pulses per second.
Also, when speaking of PI transmitter signals they should be referred to as PPS (pulses per second) not frequency.
A PI transmitter sends out bursts of square waves at controled intervals not a continuous sine wave like mains power or radio transmission or VLF detectors.
Each square wave pulse is made up of a group of sine waves of particular frequencies and I am wondering if by varying the frequency of the signals within each square wave a form of discrimination could be achieved.
The so called frequency adjustment changes the time between each pulse very slightly and is used for reducing the effects of low frequency interference and in no way effects the infiniums discrimination or sensitivity to differing metals.

Cheers.
Adrian

 

[Cupajo]

Hi Adrian,

Good info.

Many thanks for clearing up a few questions for me too.

Regards,

Cupajo

 

[Adrian SS]

A lot of questions have been asked on this forum and others as to whether the frequency adjustment of the infinium effects the response to different metal types.
The frequency adjustment only shifts the PPS by a small amount in the order of maybe 20 to 30 PPS, I am not sure of the actual figure and this is not enough to effect the detectors sensitivity to any metal.
If the PPS was up around 2 or 3 kHz there maybe a slight increase in sensitivity to small targets.
A PIs sensitivity to any given metal type is largely determined by the power of the output pulse and the pulse delay timing.

With VLF detectors the sensitivity is determined by frequency and power output; The higher the frequency the better the sensitivity to small targets but high audio frequencies do not penetrate very deep so depth is lost. Low frequency audio penetrates very deep and can generate strong eddy current flow. Haven't you noticed how when the local hoon wagon goes past your house at 3 in the morning with the stereo blasting away that all you here is the Base notes Those very low frequencies can pretty much be made to go through anything.

So I guess the thing to do is to combine pulse induction square waves with VLF sine waves in such a way that you end up with a signal that will discriminate well and penetrate anything and instead of beeping in a headset an image of whats in the ground will be displayed on a computer screen.
Cheers,
Adrian SS

 

[gjbateman]

It is my understanding that the Infinium is always pushing 96 frequencies into the ground. The frequency adjust knob only shifts or changes those frequencies very slightly. i.e. Not enough to affect how a particular type of target responds.
Here's what Garrett emailed to me a while back:
"The transmit bandwidth of the Infinium unit is 500HZ to 150 kHZ. The Infinium has 32 channels and each channel has its own set of 96 frequencies that move inside the transmit bandwidth."

Seems like there is a lot of information that the receiver is collecting. Perhaps headphones are not the best display (sound) for all that information. Has anyone ever thought of sending the output to some type of display that could discern the signals better than headphones. Maybe I'm not describing this the best way, hopefully someone gets what I'm trying to say and can elaborate.

I have got pretty good making decisions based on the sound but it took a long time to develop that ability.

 

[drayegon]

My understanding of it is. Please believe me it is a little slanted as well. They did the Infinium with sound only because that is one of the most unused things that you have available when you are diving. YOu do not use your hearing when looking for treasure or sharks or bacarudas yes I do know how to spell barracuda's OK! You are either using touch or sight when you are under water so they figure and were told by many of us who dive than to do it with sound would be the best thing there was. Same thing with the iron check. The could put a button on it to short the dial out. Then hook up a light to it. Still it makes more sense to have the one knobs twisted and it sound different then you wont forget to turn it back as you know it is not right that way. Trust me on this once you have seen the DVD on the Infinium you will be able to get a lot more out of it.

73
dray

 

[king-ghidorah]

So I guess the thing to do is to combine pulse induction square waves with VLF sine waves in such a way that you end up with a signal that will discriminate well and penetrate anything and instead of beeping in a headset an image of whats in the ground will be displayed on a computer screen.
Cheers,
Adrian SS

You've just became a millionaire. Patent it!

 

[kmantzouranis]

I have a question for everyone (if you have the patience to listen to the audio - if not, I'll describe the symptoms here)
I purchased the unit NEW from "Metal Detectors for Less". I am experiencing some "weird" tones. It seems that calibration does NOT work.
* ENVIRONMENT: I am in my living room in an urban area two-story townhouses, with underground power cables, overhead lights (turned off) and the detector propped on a chair with the
coil positioned vertically, 3 feet off the wooden floor.
* When I switch the Freq. Adj. on with Discrimination to "0" I get some faint whispering low/high tones. When I attempt to "stabilize" the tone (according to instructions) I get the following:
NOTE: I turn the knob quarter turns, for example, I start from Zero (0) and turn it a quarter turn (0.25) towards the value of 1, (to reach "1" I need to turn the knob FOUR times)
I have recorded the whole thing on audio, so if anyone is interested hearing it, I can email it to you. Since it's not fun listening to the whole thing, I listed the time-frames of the discrepancies. "TIME" in capital letters indicates the crazy thing that goes on...
====================================================
Discrimination from 0.00 - 1.50 (tone is faint but rapid high-low)
Discrimination from 1.50 - 1.75 (tone is faint but high-low slows and increases slightly)
Discrimination from 2.75 - 2.75 (tone gives a loud hi tone and continues usual tone variation) Time: 0:51
Discrimination from 3.00 - 3.00 (tone gives a sharp low, high... continues usual tone variation, then loud low-high followed by faint rapid high-lows) Time: 0:53 - 0:57
Discrimination from 5.25 - 5.50 (between those two values, tone gives constant WILD LOUD high-low signals) WHAT THE HECK GOES ON HERE?!?!??? TIME: 1:30 - 1:39
Discrimination from 6.00 - 6.00 (tone gives constant same WILD high-low signals, but not as loud as before) TIME: 2:12 - 2:18
Discrimination from 6.25 - 6.25 (tone gives constant same wild high-low signals, but not as loud as before)
Discrimination from 6.50 - 7.00 (same as discrimination around 1.00 - 1.50)
Discrimination from 7.25 - 7.50 (after about half second tone gets louder but unbelievably rapid highs-lows) Time: 2:34
Discrimination from 6.75 - 8.75 (same as discrimination around 1.00 - 1.50 with one low tone)
===================================================
ANY HELP FROM ANYONE WILL BE GREATLY APPRECIATED

FILE NAME: LS100130

 

[king-ghidorah]

I am not a Pro with the Infinium but my first guess is your environment which is inside the house. The LS will pick up on everything so inside the house is not a good choice. Take it outside to a beach or wooded area far from all electrical devices.