Using 0 Disc and monotone?

Tom, I recall you posting about the barber dime you found in the bed of nails, and you reported that you were using monotone, with (IIRC) 0 disc, 99 sensitivity, and BP mode, and the dimes TID was something like 21 or 22. You initially moved off the target but came back to it a few hours later and decided to dig it. With low sounding tones and the VDI displaying anything but dimes, what made you decide to dig it? I just can't understand why you decided to dig what appeared to be a ferrous target. I personally do not like using monotones. It makes you keep your eyes glued to the screen and the constant sounds become overwhelimg and tiresome. How ever, I think you mentioned that moving to 2 or more tones can tend to change the disc level. Am I getting this wrong or is the F75se sort of like a crap shoot? Try this try that, wow that worked "this time." Gee, I think from now on I will dig all low toned VDI 21-22 targets. Maybe I shouldn't be spending too much time asking these questions as I have reached the end of my limits with this machine. It wil be putting it up for sale pretty soon. Time to try something else. Not sure what yet.

If you haven't already, try using just the 5" coil, it is still really powerful, and a lot less noise. If your new to the 75SE, its the best way to learn.

NO NO NO!!!!! It was monotone and Disc '6' !!!!!!!!!!!! HUGE difference.

Using multi-tones is where you (and I) can get away with a Disc '0' setting.

I refuse to have my eyes/face glued to the VDI faceplate.

The Barber dime ID'd as a '13'........... which is a iron VDI. But............ in monotone with Disc '6'......... it was a good solid audio 'beep'. If I would have been in any of the multi-tones options............... the tone on a target that ID's as a '13' would be a iron tone.
(((Nails came out of the same hole as the silver Barber dime))).

I think I wrote this article in the thread titled "Rcpt Ack of F75 LTD Prototype" ........ or it may have been in COMPILATION #1 OR COMPILATION #2.

ramer Wrote:
-------------------------------------------------------
> Tom, I recall you posting about the barber dime
> you found in the bed of nails, and you reported
> that you were using monotone, with (IIRC) 0 disc,
> 99 sensitivity, and BP mode, and the dimes TID was
> something like 21 or 22. You initially moved off
> the target but came back to it a few hours later
> and decided to dig it. With low sounding tones
> and the VDI displaying anything but dimes, what
> made you decide to dig it? I just can't
> understand why you decided to dig what appeared to
> be a ferrous target. I personally do not like
> using monotones. It makes you keep your eyes
> glued to the screen and the constant sounds become
> overwhelimg and tiresome. How ever, I think you
> mentioned that moving to 2 or more tones can tend
> to change the disc level. Am I getting this wrong
> or is the F75se sort of like a crap shoot? Try
> this try that, wow that worked "this time." Gee,
> I think from now on I will dig all low toned VDI
> 21-22 targets. Maybe I shouldn't be spending too
> much time asking these questions as I have reached
> the end of my limits with this machine. It wil be
> putting it up for sale pretty soon. Time to try
> something else. Not sure what yet.


i'm in general agreement with this! i don't find it a an enjoyable detector to hunt with!
no matter how it is set,it requires the patience of "job" ,and it's tiring,and more like work to hunt with it!
isn't the hobby supposed to be fun? be tryin' somethin 'else soon! too! got my eye on a omega for coin huntin'
apparently better id especially at depth,and more stable too not as squirrely!..just sayin'

(h.h.!)
j.t.

NASA-Tom Wrote:
-------------------------------------------------------
> NO NO NO!!!!! It was monotone and Disc '6'
> !!!!!!!!!!!! HUGE difference.
>
> Using multi-tones is where you (and I) can get
> away with a Disc '0' setting.
>
> I refuse to have my eyes/face glued to the VDI
> faceplate.
>
> The Barber dime ID'd as a '13'........... which is
> a iron VDI. But............ in monotone with
> Disc '6'......... it was a good solid audio
> 'beep'. If I would have been in any of the
> multi-tones options............... the tone on a
> target that ID's as a '13' would be a iron tone.
> (((Nails came out of the same hole as the silver
> Barber dime))).
>
> I think I wrote this article in the thread titled
> "Rcpt Ack of F75 LTD Prototype" ........ or it
> may have been in COMPILATION #1 OR COMPILATION #2.

A good solid audio beep? Wouldn't any good chunk of ferrous metals give a good solid audio beep? What you are saying still makes no sense. If I were to deep every good solid audio beep in a monotone mode I would be in traction in less than a week. On a 3 hour hunt with the chatty cattie F75se I get good solid audio beeps of ferrous targets thousands of times.

Ramer, I think the general idea is that disc-ing out iron items that ID as 12 or less eliminates almost all iron, and hence a target that ID's as 13 up is likely to be non-ferrous. It's a method used to extract the maximum number of non-ferrous targets. If you prefer things simpler, disc out things below 15, or rely on the audio indication of iron in 2,3, or 4 tone modes.

............... also............ the concept is........ only small nails will be Disc'd out; yet, medium and large iron items (axe heads, files, horse shoes etc...) will audibly report as a good tone (target); yet, the astute detectorist will know that the audio report is more broad in nature on these larger iron implements; subsequently, being a clue that it is a large iron item.

Hi Ramer…

Using the monotone in concert with a discrimination setting of “6” in the DE or PF modes to eliminate or break-up signals from small iron tidbits is an advanced technique particularly useful to relic hunters searching in high iron junk density sites. As noted in a previous post, it is not for everyone because the technique does test your tolerance to noise / chatter. Moreover it is more vulnerable to EMI sources than would be the use of higher discrimination settings.

Under some conditions potentially good non-ferrous targets can target ID in the iron category. How does that happen? It occurs when searching (a) in mineralized disturbed ground such as urban renewal projects where the soil has been moved around, and (b) in soils with higher magnetic susceptible iron mineralization. In both cases, targets at moderate and deeper depths can and frequently do read as iron. The other example that comes to mind is as Tom has described (c) searching iron-infested sites where non-ferrous targets are co-located with iron junk.

Most non-ferrous targets that read as iron will target ID in the upper iron range. By using a setting of “6” or even slightly higher in DE / PF modes, we at least can eliminate or break-up signals emanating from small iron tidbits such as small nails. This setting permits potential non-ferrous targets registering in the upper iron range to produce a signal. Depending on search conditions and operator discretion… you can elect to dig…or not…but at least you are aware of a potentially good target.

Using the “6” iron discrimination setting is more stable than the “0” setting particularly as magnetic susceptible iron ground minerals increase, and it reduces the vulnerability to EMI. As Tom described on your other thread, the gain incrementally increases as discrimination is decreased from settings of 4 to 3 to 2 to 1 to 0 being the highest gain discrimination setting available on this unit. There is a gain increase in the foil range to help offset any depth reduction associated with using higher discrimination levels. But… instability from that gain increase is partially offset by the effect of using that increased level of discrimination.

If the constant signals from iron junk get on your nerves using minimal discrimination settings… there are alternatives. Try the “6” discrimination level in concert with invoking the iron tone or other multi-tone. Only those targets in the iron range from a discrimination setting of “7” through to “15” inclusive will signal with the low iron tone, while targets at or below a setting of “6” will not signal. This option quiets things down and leaves you with the choice of digging those “good” iron signals… or not….depending on site conditions, signal size and shape. This alternative is much easier on the ears.

A second option is to search using either monotone or multi-tones with full iron discrimination at a setting of “15” to eliminate small iron signals while further improving operating stability overall. This alternative eliminates most small iron and therefore it eliminates iron low tones if using a multi-tone setting… but still provides you with the higher conductive tone ID. Or if you’re a park / school coin hunter you may wish to jack-up the discrimination even more…perhaps into the mid-foil range…to eliminate those endless pesky aluminum foil tidbits. If the EMI instability is an issue even at that discrimination setting at a given site… then reduce the gain until you acquire reasonable stability. But be aware that using full iron discrimination or iron tones will result in passing over occasional good targets...so adjust your settings according to the site conditions if you want to ensure hearing most potentially good non-ferrous targets.

A third alternative that can be used in concert with the above suggestions… is to use a smaller coil. It will make quite a difference in operating stability and chatter… because small coils see less targets, see much less ground mineral and see much less EMI compared to the stock 11” DD coil. Moreover, small coils can accommodate higher gain levels as a result. Concentric coils see more ground mineral than do DD coils but are comparatively better shallow iron discriminators… whereas DD coils see more EMI… resulting in more EMI induced instability.

As a compromise / trade-off you may want to try the 5” DD in conjunction with the above suggestions. That coil does remarkably well with target separation, and although there is some depth reduction the advantages in your applications may be a worthwhile solution for you.

On a separate note…watch out for the notch feature inadvertently being turned on particularly in the iron range. It can happen and we sometimes don’t notice it. Accidentally notching out iron discrimination…even partially…ruins your iron discrimination on small stuff and returns the unit to high gain status. Note that any "notch" discrimination does not show-up on the screen when the discrimination feature is activated / highlighted. By contrast, any discrimination setting will appear when the "notch" feature is activated.

Jim.

AMEN!

ramer Wrote:
-------------------------------------------------------
> NASA-Tom Wrote:
> --------------------------------------------------
> -----
> > NO NO NO!!!!! It was monotone and Disc '6'
> > !!!!!!!!!!!! HUGE difference.
> >
> > Using multi-tones is where you (and I) can get
> > away with a Disc '0' setting.
> >
> > I refuse to have my eyes/face glued to the VDI
> > faceplate.
> >
> > The Barber dime ID'd as a '13'........... which
> is
> > a iron VDI. But............ in monotone with
> > Disc '6'......... it was a good solid audio
> > 'beep'. If I would have been in any of the
> > multi-tones options............... the tone on
> a
> > target that ID's as a '13' would be a iron
> tone.
> > (((Nails came out of the same hole as the
> silver
> > Barber dime))).
> >
> > I think I wrote this article in the thread
> titled
> > "Rcpt Ack of F75 LTD Prototype" ........ or it
> > may have been in COMPILATION #1 OR COMPILATION
> #2.
>
> A good solid audio beep? Wouldn't any good chunk
> of ferrous metals give a good solid audio beep?
> What you are saying still makes no sense. If I
> were to deep every good solid audio beep in a
> monotone mode I would be in traction in less than
> a week. On a 3 hour hunt with the chatty cattie
> F75se I get good solid audio beeps of ferrous
> targets thousands of times.


me too! it gives "tons" of info about targets in the ground,however
is a "challenge" to listen to! gonna try one more thing before giving up
on it.i was advised to set the disc to around 55,or 60,and set "gain" to
around 60,use 2 f mode,and use "only" the 5" dd coil! as i am strictly a coin hunter,
my concern is loss of depth,but i WILL try this to determine if it can find anything
at those settings!..just sayin!

(h.h.!)
j.t.

HumblePie Wrote:
-------------------------------------------------------
> Hi Ramer…
>
> > A second option is to search using either monotone
> or multi-tones with full iron discrimination at a
> setting of “15” to eliminate small iron
> signals while further improving operating
> stability overall. This alternative eliminates
> most small iron and therefore it eliminates iron
> low tones if using a multi-tone setting… but
> still provides you with the higher conductive tone
> ID.

> Jim.


Thanks for you reply. I tried the second option with my F75se. This is not an option for me or at least for my particular F75se. My machine will give a false positive at the edge of almost all ferrous targets. If the ferrous target is large enough, it will even give a false positive 6 inches or even a foot beyond the edge of this large ferrous target. If I am in 3 or 4 tones, this false positive will sound like a a quarter or dime target or some silver target. So if I were to disc out ferrous altogether I would be forever thinking I am detecting good targets. If I don't disc out ferrous objects then I know I am getting false positives at the edge of the ferrous target as my coil passes over it. Maybe my machine is defective, can't be sure until I see if someone else's F75se does the same thing, then I will know it is either in need of repair or this is just how the F75se behaves. If the latter is true then this is not the machine for me. Thousands of false positives on a typical outing is not what I want. It is not a pleasant way to metal detect.
To sum it up, if I don't disc out iron I can at least hear the iron tone and then the high tone at the edge of it. I know not to dig this false positive. Yeah, maybe one out of 500 times or 5000 times there is a quarter laying next to an iron hammer and it is not a false positive. Do I want to dig 500 or 5000 falses to find one quarter? NO! This to me is not an example of a detector that can seperate trash from treasure when the trash constantly acts like treasure. I think it is time to sell this thing and try something else.

Your sensitivity is too high. I've made these mistakes too. The falses will become more obvious the more you hunt.

Quote

I think it is time to sell this thing and try something else.

The F75 has its share of issues, but we could have this discussion with all detectors - it would just be a different issue. It might be better to stick with it and learn that one.



Edited 2 time(s). Last edit at 04/24/2012 01:30AM by Shambler.

Shambler Wrote:
-------------------------------------------------------
> Your sensitivity is too high. I've made these
> mistakes too. The falses will become more obvious
> the more you hunt.
>
I should have mentioned that the numerous false positives occur with lower sensitivity settings. Settings below 50 or 40. Someone on another forum likened the sensitivty control to nothing more than a volumn control. The false positives are still there but at a lower volumn. When it's more work than fun then it's time to do something about it.

I also should have mentioned that after 80 hours of use with this machine I have learned to just ignore the falses. But I also have to wonder if I've begun to ignore too much. Another strange occurance with this machine is that it will often false at the end of a swing as I stop and just before I start the reverse swing. And yes, I am careful not to raise the coil at the end of my swings. I've tried re-routing the coil cable in various configurations being careful not to alow too much slack which would alow the cable to wobble at the coil head. I think it is just a machine that has its issues. Maybe they all have their issues, I just have to decide which ones are the least bothersom to deal with.

Ramer, do you have another coil to try? I had the same problems after my coil was submerged or the dew made it's way into it. Fisher gave me a new coil and the 75 worked fine. In my area it runs best at max sens, 0 disc, de mode (older 75), 4 tones. If EMI is a problem, turning down the sens dosen't help but upping the disc does. Doing a freq shift seems to help, but so minor, I can hardly tell the difference.
Something isn't up to snuff with your unit. If I were you, I'd send it in, it's a machine thats worth keeping.

Yes............ it's starting to sound like a bad coil (or coil wire).........................or............................

Try different Grnd Balance settings........... especially lower numbers.

Great info!! Thanks!

ozzie Wrote:
-------------------------------------------------------
> Ramer, do you have another coil to try? I had the
> same problems after my coil was submerged or the
> dew made it's way into it. Fisher gave me a new
> coil and the 75 worked fine. In my area it runs
> best at max sens, 0 disc, de mode (older 75), 4
> tones. If EMI is a problem, turning down the sens
> dosen't help but upping the disc does. Doing a
> freq shift seems to help, but so minor, I can
> hardly tell the difference.
> Something isn't up to snuff with your unit. If I
> were you, I'd send it in, it's a machine thats
> worth keeping.

I already had to send in the 11 inch coil about 2 months ago. They replaced it at no charge. Can't beat the Fisher customer service for sure.
And yes, the 5 inch coil behaves exactly like the 11 inch coil. It gives a high toned false positive at the end of most of my swings.
Ok, well, thanks for all the replies and help. It's up to me now to decide what to do.

If your getting alot of false positives at the end of your sweep, perhaps your 'particular' sweep speed is not correct for the F75. End of sweep falsing indicates possible sweep technique issues. Try different sweep speeds in same exact area (ground) you get end of sweep falsing. See if it makes any difference in amount of falses.