Thoughts on a comment Keith made on the F752

In one of the earlier post Keith brought up that with the added EMI rejection what if FT had added more sensitivity. Not exactly worded but close.
Dont really remember any replies on that comment but seems reasonable to me.

First thoughts would be that if they had everyone would be complaining about not being able to run wide open without emi and there was no improvement.

Not having any clue as to what or when their new flagship detector will be revealed but I feel sure that one of their main objectives will be to keep the new emi resistant software as a top priority.

Would be nice though to have the option to push it to the limits/edge and gain the benefits it would bring.

Maybe a 2nd BP process that is tied to the sensitive control or something along those lines.
For sure the manual would have to state that the 2nd bp will make the machine more prone to the effects of emi.

Dwight

I hope the engineers at Fisher are thinking like you are....nice usable evolutionary changes would be great...

Good catch pac...

yes on the F75 it feels now like they could push gain further...

I hope as the go on with this or new platform or whatever the choose that they offer some thing to bring it up to date with the DEUS/GMP...DTVG..CoRe...AT series...in terms of having a blendy audio..the black and white audio the f75 is holding it back....or at least let us have user defined tone break...

Keith

Maybe the FW/SW updates to the F75 ARE from the development of the new model....if so, great way to test out some of the newer tech involved....

Agree, Keith, enjoying the F75SEupdate a lot these days, and just happened to wonder to myself, "where is the proportional audio?" But to their credit, they do have a depth meter.

Pleasant Garden, NC
AT Max, Nokta Impact, MX Sport, Nokta FORS Relic, GPX 4800, Infinium, Racer, Deus, F75SE, Nautilus DMC II (order of acquisition, last to first)

Does an archeologist argue with a plow? A bureaucrat with a bulldozer?

You can push the gain further if you set your disc to 0.

Given that it still applies to the F75-2, there were certain disc level settings that would kick in additional sensitivity/gain. Sorry I don't recall what they were, but IIRC once the disc went over something like 4, the sensitivity went into a somewhat reduced mode. I believe the T2 also had similar characteristics.

I run on zero disc..and it deeper..but still quiet..LOL.

Keith

Keith Southern Wrote:
-------------------------------------------------------
> I run on zero disc..and it deeper..but still
> quiet..LOL.
>
> Keith


Keith there were some magic disc values on both the F75 and T2, do you recall what they were? IIRC a disc of 22 on the F75 put it into a reduced gain mode.

I believe that Tom D. posted them.

I had a site that I had pounded at a disc setting of 6. I got literally hundreds of indian's out of it. it was about a half of an acre sized site in the woods. After detecting it for a few months with the finds dwindling, I started experimenting with the disc. When I would get a target that reported as iron, (but had kind of a good feel to it) I'd gradually start lowering the disc one number at a time. Quite a few of those "nails/ junk targets" turned out to be more Indians. Funny thing was that after going to 0 on the disc, those targets not only sounded good, but would also ID properly as well, where they didn't before That was a real eye opener for me, and I have used 0 disc ever since, except for a few problem areas I detect once in a while. Some of those problem sites are fields with a lot of cow urine in them. I will lower the sens to maybe 85 or 90 to quiet the machine, but if I have to go below 85 sens, I will start dialing in disc one number at a time till it settles down. Usually don't have to go higher than 4, but sometimes have to go to 6. I can still dig deepies at 6, but you have to listen for that little sweet sound in the iron response. ( gotta hear it to describe it) My goal is to run 99 sens. and o disc every time, but obviously that's not always possible.



Cal_cobra Wrote:
-------------------------------------------------------
> Keith Southern Wrote:
> --------------------------------------------------
> -----
> > I run on zero disc..and it deeper..but still
> > quiet..LOL.
> >
> > Keith
>
>
> Keith there were some magic disc values on both
> the F75 and T2, do you recall what they were?
> IIRC a disc of 22 on the F75 put it into a reduced
> gain mode.
>
> I believe that Tom D. posted them.

Streak! Wrote:
-------------------------------------------------------
> I had a site that I had pounded at a disc setting
> of 6. I got literally hundreds of indian's out of
> it. it was about a half of an acre sized site in
> the woods. After detecting it for a few months
> with the finds dwindling, I started experimenting
> with the disc. When I would get a target that
> reported as iron, (but had kind of a good feel to
> it) I'd gradually start lowering the disc one
> number at a time. Quite a few of those "nails/
> junk targets" turned out to be more Indians. Funny
> thing was that after going to 0 on the disc, those
> targets not only sounded good, but would also ID
> properly as well, where they didn't before That
> was a real eye opener for me, and I have used 0
> disc ever since, except for a few problem areas I
> detect once in a while. Some of those problem
> sites are fields with a lot of cow urine in them.
> I will lower the sens to maybe 85 or 90 to quiet
> the machine, but if I have to go below 85 sens, I
> will start dialing in disc one number at a time
> till it settles down. Usually don't have to go
> higher than 4, but sometimes have to go to 6. I
> can still dig deepies at 6, but you have to listen
> for that little sweet sound in the iron response.
> ( gotta hear it to describe it) My goal is to run
> 99 sens. and o disc every time, but obviously
> that's not always possible.
>
>
>
> Cal_cobra Wrote:
> --------------------------------------------------
> -----
> > Keith Southern Wrote:
> >
> --------------------------------------------------
>
> > -----
> > > I run on zero disc..and it deeper..but still
> > > quiet..LOL.
> > >
> > > Keith
> >
> >
> > Keith there were some magic disc values on both
> > the F75 and T2, do you recall what they were?
> > IIRC a disc of 22 on the F75 put it into a
> reduced
> > gain mode.
> >
> > I believe that Tom D. posted them.

Now that's really interesting in regards to lowering the disc and the TID becoming more accurate! I'll give that a try, sounds like it would work well at some of these iron infested sites we've been working had and the finds "appear" to be drying up. Thanks for the tip!

Any time you increase gain....... and can NOW start (for the first time) detecting a target.......... you may get an ID. If ...... at lower gain settings..... you are not detecting a target; subsequently, you will never acquire a ID.

I believe all of the other questions (about Sens increases/decreases via Disc changes) are answered in the thread titled: Rcpt Ack of F75 LTD Prototype.

I hunted a church today in old part of town. Some civil war possible camp, big open lot about 5 acres. Area used to be farmed and I know kids played ball back in mid 60's. Probably earlier. I have found a couple of old items, knapsack piece, very old lock piece, and some modern clad. My ? Is why almost every time I move the coil I hear an iron drag and most of the time the vdi number is high and the sound is a high sound. I have tried several different settings what can I do to change iron from sounding off "high". This sound also happens at another park. Still trying to figure the 75 out. All input is appreciated.

Try a different Grnd Bal setting.... like 10.... then 20..... then 30 points from norm.

NASA Tom was your reply to my iron issue?
When I auto balance it was 58 I raised it to 61. Should I still start at 10. I started out 99!sens and machine was real smooth. Could not do that before update but after an hour or so I decreased the sens and that helped a little. But I don't understand why iron has such a high sound even nails. I can tell it is iron but with all the talk on this site about good targets next to iron it makes me wonder if I should be digging all those high sounds. Then I remembered your bb story and sure enough a guy that lives near told me the kids used to shoot bbs a lot. So that made we wonder, then another post I read said 0 disc and Indians started sounding right and the ID got better. Ohhhh what to do???? Here was my settings for most of day
Je some Bp
6 disc
3h
60 gb
This was a wide open clean looking church lot with some trees. There was some iron and old nails how would you set up. Old part of town and I know there had to be activity here ( kids, picnics, camp etc
Thanks

Do not use 'je' mode for now. (You are not looking to find BB's). Use 'bp'. Start with Sens on 70. If unit is Grnd Balancing around 58.......... try 48 or 38. If high-tone falses get worse............ then try Grnd Bal numbers of 68 or 78. One of the quickest ways to do this............ is ................... if you dig up a high-tone nail.......... put it back on the ground. Sweep your detector back over the nail listening to the high-tone. Then,,,,,,,,,,,, whilst sweeping the nail with your coil............. start raising or lowering Ground Balance. See if there is a change.

What tom says works...hers is my take on the F75/F70 machines...what i have noticed is if there is only a quick high tone mixed with alot of low grunts it always seems to be iron...when i hear a clear high tone very repeatable and a low grunt or two its always seems to be a good target mixed with iron.. Couple days ago kind of screamed this theory...was hunting an old park ive hunted to death for 30 years..got a good high 80's low 90's signal very repeatable with a small clip of a low grunt..dug target and at about 7-8 inches was a rusted partial roll of very old wire.. I thought ok a false signal..waved coil over hole and a nice clear signal still...dug 2 small nails on other side of hole..pinpointer showed more metal so dug under where wire was and about an inch or two below that out pops a green wheaty.. Now ive used whites for so long i dig tons of iffy signals cause with whites i was rewarded alot.. With the F75 if a good target is in the ground mixed with rusty metal it always seems to give a good tone with a decent vdi maybe jumping around but in a good area..if i dig what whites machines says to dig on the iffy low grunts mixed with high tone vdi jumping down close to zero it always is junk..just my experience..

Thanks Nasa Tom and basstrackerman, goi g to experiment a little with this today and see how it goes.

I detected a park scrape yesterday with the F75 Ltd2 setup in 1 disc, 99 sensitivity, BP mode and 3H tones and it ran smooth! I've never been able to do this in the past without the machine being unstable and/or overly noisy. I actually started off in 0 disc, and it was a little bit noisy. I pulled the saddest looking standing liberty quarter I've ever seen, shame as it's only the third one I've ever found.

Tom is there any real world advantage to using 0 disc vs 1 disc?

Slightly better depth.
Slightly better ID.
More iron chatter.

NASA-Tom Wrote:
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> Slightly better depth.
> Slightly better ID.
> More iron chatter.


Thanks Tom. Truth be told, when I tried using 0 disc vs 1 disc, it still ran better then it did before the DST upgrade. I always used to run the disc between 4-7 pre-DST days.

Great so 0-1 disc is resulting in less audio fatigue, better depth, better TID, perhaps more iron chatter (not really noticing it....yet), I think the potential of the F75 is finally being realized! Hopefully it's ability to detect small silver (dime sized and smaller) at depths over 6" deep is also much improved.