Explorer "Noise cancel" question

[mainer]

Re: Explorer "Noise cancel" question

Now I got ya. Thought I had it before, but I got it now. Getting late for me, not too mention Im losing my mind.

 

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[Captn SE]

Re: Explorer "Noise cancel" question

The noise cancel has nothing to do with it. Even if they had not hit it, their sens would have been different because it's the ground conditions that make the auto react. Noise cancel is just for electrical interference and doesn't affect the sens..

I'm going to have to disagree with you on that statement, IP.

The coil doesn't know the difference between magnetic ground interference(ground mineralization) and electrical interference above the ground, such as EMI. EMI could be underground also, such as electrical wiring. So EMI can affect the sensitivity of your machine when you're in auto sens., thus the noise cancel affects the level of auto sensitivity by selecting the channel with the least EMI.

CAPTN SE
Dan

 

[Iron Patch]

Re: Explorer "Noise cancel" question

The noise cancel has nothing to do with it. Even if they had not hit it, their sens would have been different because it's the ground conditions that make the auto react. Noise cancel is just for electrical interference and doesn't affect the sens..

I'm going to have to disagree with you on that statement, IP.

The coil doesn't know the difference between magnetic ground interference(ground mineralization) and electrical interference above the ground, such as EMI. EMI could be underground also, such as electrical wiring. So EMI can affect the sensitivity of your machine when you're in auto sens., thus the noise cancel affects the level of auto sensitivity by selecting the channel with the least EMI.

CAPTN SE
Dan

You'd have to be in extreme conditions for interference to have anywhere close to the same reaction the ground does. That's because most of us hunt where there is a lot of trash and the detector in auto will adjust down as low as it has to. I also wrote it had no affect in the context of what was going on in the situation above because the ground could have easily been the difference but was not considered. Lucky for me the only inference I tend to run into is another explorer although I have been a couple places that were very bad, and one impossible.

 

[halfstep]

Re: Explorer "Noise cancel" question

I have a question about all the different frequencies.

I am look at the safari really hard and don't quit understand the concept of having all those frequencies. The coil can only be fully tuned to one frequency to operate at it's best. If you change the frequency other than what the coil is tuned to, wouldn't it operate less effecient? The head unit can change frequencies but the coil can't. What am I missing?

 

[Captn SE]

Re: Explorer "Noise cancel" question

You'd have to be in extreme conditions for interference to have anywhere close to the same reaction the ground does

Extreme conditions for one person may be hunt-able conditions for another who has a higher tolerance for "chatter". The point is that any amount of EMI will negatively affect the auto sens. of an Explorer/E-Trac. Many times in my urban parks I've experienced EMI....EMI where you have to frequently and manually change channels on a constant basis as you detect through the park...I know it's EMI because the higher I raise my coil, the louder and more chatter/falsing I hear......on a few occasions, I tried going into auto sens. instead of changing to a different channel, and fairly quickly the machine becomes stable....and I know it got stable because the machine dropped the auto sens. way down. I can test that by going back into manual sens. and dropping the sensitivity down until the EMI was squelched....result was terribly low sensitivity values. That's why I'd rather hunt in manual sens. and tolerate some chatter. The priority of auto sens. is to always sacrifice depth for stable operation.

In those areas you stated where you had really bad EMI conditions...if you had been auto sens. and were able to see what your sensitivity was (like you can with an E-Trac), you probably would have seen very low values. Even the E-Trac manual states it would be better to use manual sens. if you're in areas that have EMI, and it suggested to always do a noise cancel before you reduce your manual sens. if you are getting a lot of erratic signals...you may be able to quiet the electrical interference with noise cancel without having to lower your manual sens.

HH,
CAPTN SE
Dan

 

[RigDean]

Re: Explorer "Noise cancel" question

Good feedback from Ironpatch and Captn_Se...Thanks guys

Here is my (limited) understanding of how this kind of works...

When performing noise cancel, you remain perfectly still and make sure the coil is not directly over any targets holding coil 12" above the ground. If you noise cancel over a metal object, detector may confuse signal as EMI and attempt to find a channel that does not receive the signal as strongly. Resulting in the wrong channel being selected and causing sens to operate lower or cause "falsing" in a higher manual setting.

I've found that if I go into quickmask (all metal) and manual sens at max, then find a spot where I can do a 2 to 3 foot sweep while still getting a threshold (not easy) before I noise cancel, my sensitivity will run higher in auto and in manual without too much falsing. (dependent on site conditions from day to day)

Noise cancelling this way, insures 1: you are not picking up readings from an object under the coil while scanning channels to be selected and 2: receiving maximum EMI in the atmosphere and from surrounding ground so the quietest channel is selected.

When I first get to a site and power up, my sens may only be at 20 (auto) for example, and after noise cancel it may jump to 27 or to 16, so I know noise cancel helps determine what sens the electronics recommend. Also, sens will adjust as I go along possibly due to erratic iron everywhere or EMI. Trashy sites seem to drive the sens down while on a "cleaner" site, sens will run higher.

Also, if having trouble with falsing and a low auto sens, try lowering gain a little before lowering sens. Lower sens will reduce detection depth as we all know, but a lower gain will only cause deeper targets to sound fainter and lowering gain first helps reduce falsing (which pushes sens lower). Also, a lower gain will reduce co-mingling of targets in the trash and increase ID accuracy. Experiment with gain to see where you can still get an audible signal on a deepie.

On a cleaner site where deep keepers are expected, try running gain a little higher if it does not affect sensitivity overly much

Dan, I didn't think of it at the time to select channel 9 and see how my sensitivity responded. I will keep this in mind next time.

IP, We were both in auto mode at the time of the observation. You can't see selected sens on explorers? Auto mode is represented by a small icon above the two sensitivity bars (suggested and actual) Manual mode the icon is absent...I too thought about my machine
being "quirked"

 

[Iron Patch]

Re: Explorer "Noise cancel" question

You'd have to be in extreme conditions for interference to have anywhere close to the same reaction the ground does

Extreme conditions for one person may be hunt-able conditions for another who has a higher tolerance for "chatter". The point is that any amount of EMI will negatively affect the auto sens. of an Explorer/E-Trac. Many times in my urban parks I've experienced EMI....EMI where you have to frequently and manually change channels on a constant basis as you detect through the park...I know it's EMI because the higher I raise my coil, the louder and more chatter/falsing I hear......on a few occasions, I tried going into auto sens. instead of changing to a different channel, and fairly quickly the machine becomes stable....and I know it got stable because the machine dropped the auto sens. way down. I can test that by going back into manual sens. and dropping the sensitivity down until the EMI was squelched....result was terribly low sensitivity values. That's why I'd rather hunt in manual sens. and tolerate some chatter. The priority of auto sens. is to always sacrifice depth for stable operation.

In those areas you stated where you had really bad EMI conditions...if you had been auto sens. and were able to see what your sensitivity was (like you can with an E-Trac), you probably would have seen very low values. Even the E-Trac manual states it would be better to use manual sens. if you're in areas that have EMI, and it suggested to always do a noise cancel before you reduce your manual sens. if you are getting a lot of erratic signals...you may be able to quiet the electrical interference with noise cancel without having to lower your manual sens.

HH,
CAPTN SE
Dan

Yes, as I said with extreme interference it would affect the sens. but under normal conditions the balance of the noise is taken care of by a freq, change, so two detectors showing a different number was probably because of the ground conditions. (What Mainer and I were talking about) The only place that I get moderate interference, but doesn't really affect my hunting is when I turn on the detector at the top of the field near some powerlines. This is almost always cleared up by hitting the noise cancel without any reduction to my man. sense which further states my point that the ground is mostly the issue when it comes to auto. sens. under normal conditions. I do realize we all hunt in different places so if that is not the same experience for others, or they don't agree, that's ok too.

 

[Iron Patch]

Re: Explorer "Noise cancel" question

Good feedback from Ironpatch and Captn_Se...Thanks guys

Here is my (limited) understanding of how this kind of works...

When performing noise cancel, you remain perfectly still and make sure the coil is not directly over any targets holding coil 12" above the ground. If you noise cancel over a metal object, detector may confuse signal as EMI and attempt to find a channel that does not receive the signal as strongly. Resulting in the wrong channel being selected and causing sens to operate lower or cause "falsing" in a higher manual setting.

I've found that if I go into quickmask (all metal) and manual sens at max, then find a spot where I can do a 2 to 3 foot sweep while still getting a threshold (not easy) before I noise cancel, my sensitivity will run higher in auto and in manual without too much falsing. (dependent on site conditions from day to day)

Noise cancelling this way, insures 1: you are not picking up readings from an object under the coil while scanning channels to be selected and 2: receiving maximum EMI in the atmosphere and from surrounding ground so the quietest channel is selected.

When I first get to a site and power up, my sens may only be at 20 (auto) for example, and after noise cancel it may jump to 27 or to 16, so I know noise cancel helps determine what sens the electronics recommend. Also, sens will adjust as I go along possibly due to erratic iron everywhere or EMI. Trashy sites seem to drive the sens down while on a "cleaner" site, sens will run higher.

Also, if having trouble with falsing and a low auto sens, try lowering gain a little before lowering sens. Lower sens will reduce detection depth as we all know, but a lower gain will only cause deeper targets to sound fainter and lowering gain first helps reduce falsing (which pushes sens lower). Also, a lower gain will reduce co-mingling of targets in the trash and increase ID accuracy. Experiment with gain to see where you can still get an audible signal on a deepie.

On a cleaner site where deep keepers are expected, try running gain a little higher if it does not affect sensitivity overly much

Dan, I didn't think of it at the time to select channel 9 and see how my sensitivity responded. I will keep this in mind next time.

IP, We were both in auto mode at the time of the observation. You can't see selected sens on explorers? Auto mode is represented by a small icon above the two sensitivity bars (suggested and actual) Manual mode the icon is absent...I too thought about my machine
being "quirked"

Does Minelab say you have to noise cancel over clean ground? (even if you raise the coil?) I don't recall reading that, but don't recall much because I haven't really had any tech. type conversations in years. (or read anything) I have always raised the coil, and maybe it's from reading the proper way to do it, but I also raise it so the other person I'm hunting with will know why their detector is wacking out. As far as this topic is concerned for my hunting it is sounding like a much bigger deal than it is here because basically what it comes down to is one of us hitting it to cut the crosstalk from the other detector and we're off. I have used man. sens. and the exact same settings for many years now so this debate is just something to do and definitely will change nothing for my detecting.

The explorers auto sens only shows the number you set it at and does not change eventhough the detector is adjusting. That's one of the reasons why many of us switched to man. years ago and never looked back. I know the explorer works better for me when it runs hot so using auto sens. would take away some of the punch.

 

[RigDean]

Re: Explorer "Noise cancel" question

IP, Now that I go back and look at the manual word for word... It does not specifically say, "to be over clean ground when noise cancelling" but what it does say is: "Hold the detector 12" above the ground and make sure there are no large targets or obvious sources of EMI close by"(page 31 of the e-trac manual.) There's a digital online version on ML website.

I suppose if you're not detecting any obvious targets when coil is raised 12" you are ok. Still, I will try to find the cleanest area for noise cancelling.

Page 75 covers manual noise cancel channel selection and hunting close to other E-tracs (all FBS Machines?). I'm thinking paper, rock, scissors to determine who gets to power up and press noise cancel first After all, He with the quietest channel will run a higher sens setting...

You are correct IP about Manual sens vs. Auto. and there is some technical lingo to back up this claim, but it is fact so that's that. People can say what they want about "airtests" but I do them to create familiarity and understanding of my machine. So, here's the results of one such airtest concerning auto vs. manual sens.

All other settings aside, it is what it is...Auto-16, repeatable signal: dime- 5", nickle- 5 1/2", quarter- 6"
Manual-16, repeatable signal: dime-6 1/2", nickle- 6 1/2", quarter- 7"

1" + depth in "airtest" from auto to manual

I usually noise cancel to begin, see where auto is running and then switch to manual. Sometimes I'm able to bump it up a notch or two in manual and remain somewhat stable. If too much falsing is present in manual, I will lower gain a notch or two first. If I'm finding older coins only 3" to 4" deep then I will just switch to auto and raise the gain if it's not too trashy. I'm confident I will get the coins as long as sens stays atleast in lower 20's. Plus ID's will be more accurate in auto....

I would be interested to see where others stand on this issue, because if I've got it all wrong I need to correct it now before I get into "bad habits".

 

[Iron Patch]

Re: Explorer "Noise cancel" question

Page 75 covers manual noise cancel channel selection and hunting close to other E-tracs (all FBS Machines?). I'm thinking paper, rock, scissors to determine who gets to power up and press noise cancel first After all, He with the quietest channel will run a higher sens setting...



I usually noise cancel to begin, see where auto is running and then switch to manual. Sometimes I'm able to bump it up a notch or two in manual and remain somewhat stable. If too much falsing is present in manual, I will lower gain a notch or two first. If I'm finding older coins only 3" to 4" deep then I will just switch to auto and raise the gain if it's not too trashy. I'm confident I will get the coins as long as sens stays atleast in lower 20's. Plus ID's will be more accurate in auto....

I don't think it will come to Rock-paper-scissors, but if it did, can you be sure the first to noise cancel gets the advantage? Point being the first detector cancelled with the 2nd detector at a specific freq., but once the 2nd cancels it most likely changes freq. therefore the first is no longer at the best setting to avoid detector 2. So with that said, in cases like my area where the other detector is the main source of interference, I'd say who cancels last has the advantage. Again, just more of a fun topic to debate because any advantage for detector 1 or 2 would be so slight you'd never even notice. There are FAR more things that separate who is going to be more successful that day and can come down to something as simple as going left or eight. A few weeks back when three of us tried a large field the Patriot went left, Ironhorse down the center, and myself to check the right side of the field. IH and I came up empty, but seen the Patriot digging targets so crossed our fingers they were old because it was pretty much our last chance for the day. Turns out it was a fairly large site and over the next 2 hours we dug over 20 large coppers. To further make the point I gambled on staying in a very small spot within the site because I had dug a few coins together, but that ended up being a mistake because the other two were cleaning up a little higher up and my dirt had gone quiet. It really is amazing how the little choices can have such a great affect on what you find.

Over several years I worked my way up to run max gain, high sens., and low disc. in conductive. It works very well and changing anything for me would be a step backwards, but these settings probably wouldn't be very easy for someone starting out because there is a lot of noise around trash. Most of my trash being old iron and I am very used to lots of snap, crackles, and pops. I've lost track of how many years I've used the same settings but I know there is no better way for me, where I hunt, and what I want to find.

 

[RigDean]

Re: Explorer "Noise cancel" question

I don't think it will come to Rock-paper-scissors, but if it did, can you be sure the first to noise cancel gets the advantage? Point being the first detector cancelled with the 2nd detector at a specific freq., but once the 2nd cancels it most likely changes freq. therefore the first is no longer at the best setting to avoid detector 2. So with that said, in cases like my area where the other detector is the main source of interference, I'd say who cancels last has the advantage. Again, just more of a fun topic to debate because any advantage for detector 1 or 2 would be so slight you'd never even notice. There are FAR more things that separate who is going to be more successful that day and can come down to something as simple as going left or eight. A few weeks back when three of us tried a large field the Patriot went left, Ironhorse down the center, and myself to check the right side of the field. IH and I came up empty, but seen the Patriot digging targets so crossed our fingers they were old because it was pretty much our last chance for the day. Turns out it was a fairly large site and over the next 2 hours we dug over 20 large coppers. To further make the point I gambled on staying in a very small spot within the site because I had dug a few coins together, but that ended up being a mistake because the other two were cleaning up a little higher up and my dirt had gone quiet. It really is amazing how the little choices can have such a great affect on what you find.

Over several years I worked my way up to run max gain, high sens., and low disc. in conductive. It works very well and changing anything for me would be a step backwards, but these settings probably wouldn't be very easy for someone starting out because there is a lot of noise around trash. Most of my trash being old iron and I am very used to lots of snap, crackles, and pops. I've lost track of how many years I've used the same settings but I know there is no better way for me, where I hunt, and what I want to find.

I agree this topic is somewhat trivial and it really does come down to how and where you swing your coil that will ultimately result in the finds. The best settings on the greatest machine in the world amounts to zero if there is nothing in the ground worth finding

I've only ever hunted with one other person besides myself and that was one time for about 2 hrs. so my experience there is limited to say the least. I've been detecting for less than 2 1/2 yrs and using FBS technology for 1 1/2 yrs so I'm still trying to find what works well for me through a clear understanding of how these machines operate. Hence, debating....

As for rock-paper-scissors there would have to be some testing done between two users of the same machine. I suppose the consensus here is he who runs the highest sens with stable operation will have the advantage for deep targets, provided there are deep targets to be found...

I see your point in the 1st few sentences above, And I'm assuming that scenario is with both detectors being powered on when detector 1 is noise canceled. If that is the case then I would say you are correct, however...let's say detector 1 powers up and noise cancels 1st. So detector 1 is at the optimal channel for site conditions only without another detector in the equation. Now detector 2 powers up and noise cancels. That machine will now be searching for the quietest channel to avoid crosstalk and EMI. Giving detector 1 the advantage...

Congrats on the large coppers I don't think we have anything like that around here. My area was still frontier and not widely settled until after 1900 and even then saying "widely settled" is pushing it. I'm somewhat surprised that you said you use conduct and hunt in the IRON. Especially from what I've heard about ferrous mode on the explorers. Then again you've found what works for you and that's good for having such a versatile machine that is capable of a multitude of settings. Can't wait til I find my optimal settings for the E-trac...

It's nice out, think I'll go see what's waiting to be dug up this time...

 

[biguglydude]

Re: Explorer "Noise cancel" question

It is not hard to understand if you try.

Boooooo!

So what if the only frequencies that aren't receiving interference are 3, 4, and 4.5 KHz? Would you now have an Explorer going 4' deep and only able to detect semi-trailers?

I think something else is happening during noise canceling, and I'm certain it's not hard to understand but you have to have the information since neither you nor I developed it. The FBS reality and the FBS marketing plan (including Sabisch) are a little different, which I'm sure you know since you've tried hard to understand Hint, the page you sent me is not from the technical department.

Gold, silver, and relics signal response aren't the reason for FBS. If you had said shallow, deep, small, and big, it would've made more sense. Gold detectors are high freq'd not entirely because of signal response - it's more to do with the size of the metal your looking for. I also don't believe for a second this machine emits 100Khz freqs (EVER!).

See if you can detect a thin gold chain or a BB with your Explorer - now try an F75. Is the F75 better? Nope - BUT it picked up the BB and chain. Is the Explorer emitting any frequency above 13Khz? If it is, why didn't it pick up the small chain or BB when the F75 did? There's more here than "trying to understand".

If noise canceling is in fact changing frequencies, I'd summise that via some type of ground tracking circuit the detector has chosen a few frequencies for detecting (and never more than a few). Let's say 5, 9, 15Khz. During noise canceling, it may be changing 9 to 9.5 and 5 to 4.3 and 15 to 14.9 but it's not arranging the primary frequencies based on that feature. Doing so, would ruin any automatic ground balance work the detector has done.

With my Explorer S, this is what I found so far. The starting frequencies per channel are approximately…
Ch1-1.78KHz
CH2-1.73KHz
Ch3-1.70KHz
CH4-1.65KHz
CH5-1.62KHz
Ch7-1.53KHz
Ch8-1.50KHz
CH9-1.47KHz
Ch10-1.43KHz
Ch11-1.40KHz
Plus, I measured Respectful Harmonic Power Levels from these starting points all the way up too and beyond 100KHz (70 plus measurements). Yes, there is 100KHz energy being transmitted!

 

[fmerg]

Re: Explorer "Noise cancel" question

I promise if you use your noise cancel more you will find more deep targets than ever before. If you like, email me and I will give you some tips that were taught me from the best hunters around. Ron from Ca. Eddie B.

i sent ed an e-mail and he sent a list of things i could do to improve the factory setting on the explorer ii (i have the se pro so not all settings applied)
i only got out for 20 mins to test the new setting and the first thing i noticed was that can slaw showed up as just that
my machine became more stable
the next thing i am going to do is take my machine out and find a weak signal using the noise cancel
then i will re-swing using each of the channel setting
i will post what i find on Monday night

and ed thanks for the reply

 

[Iron Patch]

Re: Explorer "Noise cancel" question

I promise if you use your noise cancel more you will find more deep targets than ever before. If you like, email me and I will give you some tips that were taught me from the best hunters around. Ron from Ca. Eddie B.

i sent ed an e-mail and he sent a list of things i could do to improve the factory setting on the explorer ii (i have the se pro so not all settings applied)
i only got out for 20 mins to test the new setting and the first thing i noticed was that can slaw showed up as just that
my machine became more stable
the next thing i am going to do is take my machine out and find a weak signal using the noise cancel
then i will re-swing using each of the channel setting
i will post what i find on Monday night

and ed thanks for the reply

I'll also share how to improve the factory setting on the explorer... get out of the factory setting. (you really should, there's no reason to stay there) In all honesty you are really making too much out of the noise cancel as the other settings are so much more important for depth, not to mention experience being the key. Focus your efforts on the major settings, not the little things that don't really matter! That said, if you got noise, hit the noise cancel, otherwise learn what counts!

 

[fmerg]

Re: Explorer "Noise cancel" question

first let me say i am sorry for not posting on monday night as promised
my tranny died on monday

ok back to the main topic "noise cancel"

on saturday i went out in to a field that i have worked over and over looking for a weak signal
(yes i use the noise cancel button at the start)
when i found what i thought was a weak hit i changed the freq setting and scanned the area again
what i found was that on a very few of the channels i could not get a hit
on some channels the hit jumped all over the place showing junk to silver
other channels i got the hits some were weaker then the others but they were there
the channel that was picked by the noise cancellation button was the best
the next thing i did was test the noise cancellation button to make sure that the same channel was picked
each time
this was done by going the the center of the field placing the coil flat on the ground
and pressing the button (5 cycles) looking at what channel was picked each time
4 out of the five times was the same channel 1 time it was two channels lower
so my conclusion is
yes there are other setting that will have a greater effect on the signals and depth
but for the few seconds it takes to noise cancel you will increase your chance slightly maybe one or two things a year
but thats one or two more then you had

as soon as i can i will post pictures of the finds i made
1865 2 cent... my first
spur.... my first
some flat buttons and other relics

I'll also share how to improve the factory setting on the explorer... get out of the factory setting. (you really should, there's no reason to stay there) In all honesty you are really making too much out of the noise cancel as the other settings are so much more important for depth, not to mention experience being the key. Focus your efforts on the major settings, not the little things that don't really matter! That said, if you got noise, hit the noise cancel, otherwise learn what counts!

IP i would love to see what setting you recommend if you would pm them to me

 

[biguglydude]

Re: Explorer "Noise cancel" question

this was done by going the the center of the field placing the coil flat on the ground
and pressing the button (5 cycles) looking at what channel was picked each time
4 out of the five times was the same channel 1 time it was two channels lower

You might want to revisit the manual. It states you need to hold the coil 30cm (approximately 12") off the ground and hold it very still while it does its thing.

On the other hand, all it is doing is measuring the nosie level on each of the channels. If they are all quiet, it might just pick the center channel by default. And because "Themal Noise" is truely random, it might detect just one dB higher or lower level on some channels and pick one of the others...even though all of them would have worked just fine.

If you have XM or Sirius radio, and you use the retransmit feature from your car stereo, you are doing the same thing. You are trying to receive the sirius transmitter with your car stereo. You search your car radio channels trying to find one that is quiet. Then you set your sirius TX to that frequency. If I travel 100 miles away I might have find another channel. Or in the metal detector case...if I walk to the other side of the field...IMHO...that is all the "Noise Cancel" feature is doing.

Listen to Iron Patch! Don't get hung up on this noise cancel thing. Sure, if I didn't have to do it manually every time, I'd do it when I first start just because it's very quick. But, if you know your detector, you know when it is acting up. Then start switching channels.

 

[fmerg]

Re: Explorer "Noise cancel" question

this was done by going the the center of the field placing the coil flat on the ground
and pressing the button (5 cycles) looking at what channel was picked each time
4 out of the five times was the same channel 1 time it was two channels lower

You might want to revisit the manual. It states you need to hold the coil 30cm (approximately 12") off the ground and hold it very still while it does its thing.

the test was not to do cancleation the reason i held it on the ground was so that know one could say oh it was held higher this time or it was moving ect.... i was trying to limet all the veribles i could