Safari Frequency Puzzle

[Monty]

I am in the process of buying a new Minelab Safari. I was watching an instructional video on the operation of the Safari. It is advertised as having the multifrequency hunting set up just as the top of the line Minelabs, but..........In the video the guy was explaining the Noise Cancellation feature. He said that, "When activated it searches and selects the quietest frequency (singular) to hunt. Will cancel the interferance of someone using a detector on the same frequency", as an example. This seems to defeat the purpose of the multi-frequency capability. Is this correct or am I misunderstanding what he is saying? Anyone know? Monty

 

[ParkHunter61]

Hey Monty
I'm looking forward to your review on
the Safari.
I was under the impression that a multi frequency
detector can only use one freqency at a time
picking the best frequency for the spot your hunting
with each swing..
But then again I'm a pretty well established dolt.
Bill.

 

[Captn SE]

I think you're misunderstanding what the video guy was saying.

The Safari, like the entire Explorer line, E-Trac, and Quattro, are designed with FBS (Full Band Spectrum) technology. This technology allows 28 frequencies (ranging from 1.5 KHz up to 100 Khz) to be transmitted into the ground. The Noise Cancel feature helps reduce EMI (Electro Magnetic Interference) from Radio Towers, underground/above ground electrical wires, business alarm systems, and other metal detectors....there are many other sources of EMI. With regards to the Explorer line, there are 11 different possible noise cancel channels that the detector can select.I would assume that the Safari has the same number. From my knowledge of these machines, I have read that the Noise Cancel channel is like a "multiplier channel" of the machine to determine the 28 operating frequencies. The detector will always be using 28 unique frequencies in the above stated range, but the actual frequencies will be determined by the noise cancel channel. For instance, just assuming the noise cancel channel 1 will have an internal multiplier of 1.1, then each of the 28 frequencies will be multiplied by that factor, giving the detector a slightly different range of operating frequencies. For noise cancel channel 2, the multiplier will be 1.12, and so forth for each of the 11 channels. The noise cancel feature will cycle through all 11 possible channels (multipliers), and try to find which range of 28 frequencies are the most quiet in your given detecting area.

I hope that makes some sense to you. It's a little hard to describe a technical process that can be understood by all who read it.

Good luck!

CAPTN SE
Dan

 

[Willy]

Judging from what I've read on other forums (Carl's & Geotech), the BBS/FBS transmit multiple frequencies (many as harmonics) but only use 3 of them at a time.. though it can be any 3. I noticed, while reading the Sov. GT manual, that ML doesn't claim to be acyually USING all those frequencies. ..Willy.

 

[Monty]

Willy I have made a similar argument to a couple of different Minelab users and they both swear they are using all of the frequencies. They claim that the target may not be picked up by all the frequencies however, just the one or maybe 3 (this wasn't clear) were the ones actually reading the target the strongest that broadcast the info back to the display? This is new stuff to me, but from all accounts it works! Thanks for the responses. I'm understanding most of it. M nty

 

[Bart@Big Boys Hobbies]

Get Andy Sabish's new book. I think it will answer allot of your questions. 3 channels is what the etrac and and explorers use according to Andy. I don't know about the safari. As mentioned above they must change the 3 between the 28 available.

I have the new Etrac and its amazing machine. Hope it gets warmer tomorrow so I can take it out to play.

 

[Willy]

Here's a question: These ML owners swear that their detectors are using all the frequencies.. how do they know this? Where's the proof? I'm not talking about "It's gotta 'cause it picks up both gold and silver reely reely fine", I'm talking concrete evidence. Hell, SHOW ME ELVIS!! And for God's sake, get him ouuta that Burger King! ..Willy.

 

[Keppy]

I am with ..parkhunter61..& Willy.... I have been useing Minelabs since 1992 ..And the way i undestand it it does not matter if your detector has 17 freqencys or a 100 freqencys it picks out the best for the area you are hunting and still only uses ..one that is one Freqency now i said ..one...not 3 not 17 not 25 not 100 but one ......Easy Money .. AKA..Lucky Larry has explained it many times here on treasurenet and the why he explaines it is the why i understood it since 1992........

 

[Sandman]

The way Minelab explains it they make it sound like the detectors put out all these frequencies all the time when in fact they don't. They show all the lil arrows pointing down from a coil and show only one coming from a competators coil. Larry, or Easy Money, as we know him explains this lots better that I would try to do.

 

[Bart@Big Boys Hobbies]

If you want it explained by someone that was in on the designing of the machines read Andy's book. He describes in the book that the machines run on a high, medium and low channel and an additional 4th channel designated as a "ground" for monitoring the ground characteristics.

I agree however that it must pick the best channels to run in your particular situation out of the 28. He didn't explain that part. I am just assuming that be true. We all know what assuming gets you. ha ha He also explains how the channels run differently in auto and manual. Very informative reading.

See pages 102-104 in his book.

 

[Monty]

What impresses me more than just the multi-channel capability discussed is the picture showing the search pattern to be flat all the way to the target while it shows the competitors to be cone shaped. I knew the search pattern was cone shaped in the detectors I owned. Is there any truth to this illustration or is it a feature of the coil used rather than the machine itself? Monty

 

[Captn SE]

What impresses me more than just the multi-channel capability discussed is the picture showing the search pattern to be flat all the way to the target while it shows the competitors to be cone shaped. I knew the search pattern was cone shaped in the detectors I owned. Is there any truth to this illustration or is it a feature of the coil used rather than the machine itself? Monty

Yeah, that's a product of the coil. The Double D coil design penetrates the ground in a blade-like style, from the toe to the heal of the coil, while the concentric coil penetrates the ground in a cone shaped fashion.

Here's some info on different coil types and their advantages/disadvantages.

http://www.goldminingcentre.com.au/Technical Data/techsheet-coils.pdf

HH,
CAPTN SE
Dan

 

[Willy]

I have a bit of a problem with the field illustration you posted; the field should be symmetrical, extending upwards the same as in the ground and also from what I've experienced of DD coils, not as narrow a 'knife-blade' pattern, nor as sharply delineated. Maybe I'll play around with my Sov. and get some hard facts. It would be nice if I were wrong, but judging from what I've read about people with WOT 'n such coils having them picking up digging tools while swinging (some people claim to have them held up and behind their backs) I'm probably correct. ..Willy.

 

[Monty]

We're getting a little off topic here, but I am enjoying the information, so keep it up! I know that on my other detectors, the picture like figure one was more of a cone shape, while figure two was more or less straight down from all sides of the coil. I have noticed that on my GTI 2500 that you can hold your digger out over the coil like you might when holding it by your side, arm extended downwards and it will somtimes cause interference. It reacts much like you would expect when hunting under a power line. Not that it is a regular occurance, but it has happened. I would excect the same thing with most any powerful detector regardless of brand. Monty