Rcpt Ack of F75 Ltd prototype

Thanks Tom what settlings did you use? I have hunted areas where there were no nails and the 5DD got 8" found a lot of history that way.

LowBoy

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tom!..in your view,do you believe that the (standard) f-75 utilizing the 5" dd
coil would achieve similar results in those conditions?..

(h.h.!)
j.t.

Settings with this 5" DD coil in the test-garden were as follows:

'bp'
Sens '99'
Disc '0'
Grnd Bal '90'
4-tone
Freq F6

In the real world.....on the actual field hunt days.....the only configuration I changed was.....Disc '1'......which reduced iron flakes audio reporting by approx 85%. A substantial 'fatigue' reduction factor.

I did test the pf & de modes in the test-garden .... but did not document depth results.......as I could tell it would be a linear... 'according' reduction in performance....per expectations......as compared to the 11" DD coil and dropping down to the pf & de modes (processes).

Another high-interest report in extreme condensed wordings: The 6.5" elliptical concentric coil did NOT perform at all...... during all of this testing. Such a small coil......with a dramatic differential electromagnetic footprint from the 11" DD coil; yet, would not seperate (and locate) non-ferrous targets in this extremely nail-infested relic (Fort) site. I suspect the windings of this concentric coil produce a electromagnetic footprint that is quite 'wide' in nature; subsequently 'seeing' too many nails/targets under the coil...at one time. Very small coil......but too wide of a footprint. These words may sound harsh; yet, reality-results prevails. The large 11" DD coil separates targets surprisingly well.....considering it's inherently large dimensions.

Yes, the resultant would be the same performance gain (linearly) with the 1st generation standard F75.

More data: For those of you that have the Inland Coin and Relic Hunting DVD. Remember the 'complex test-garden'. Three ferrous nails....and one non-ferrous dime. I could rotate my body approx 2-Degrees (out of 360 Degrees) and detect the dime between the nails with the CZ. The F75 LTD with 11" DD coil will ascertain ID resolution on the dime with 8-Degrees body rotation. Thats 4X (4 times) better than concentric coil CZ. ,,,,,,,, Installing the 5" DD coil on the F75 LTD.....and I can rotate my body 52-Degrees ...and detect the dime. ((( That's 26X better than the CZ ))). Is this starting to 'paint a picture'?

Tom

Could you venture even a 'estimate' on the depth in 'inches' you got in the dE mode with the 5" DD. I would settle for that. I know estimating is not your normal mode of reporting things......lol



Edited 1 time(s). Last edit at 02/03/2011 04:50AM by TerraDigger.

yes!..a very clear "picture!"..thankyou!

(h.h.!)
j.t.

5" DD coil in 'de' or 'pf' mode.......guesstimation on a clad dime would be.....say.......right at....or just over 10". (Time permitting.....I'll test this.....Keep reminding me!).

And yes!!!!! I will be a 'pest' and remind you.

Just did a quick Air test Senc at 90 Disc of 6 and 3 Tone
DE mode on clad dime 8in repeatable ID
Boost mode same settings 10in repeatable ID
Should be interesting to to see ,in ground results.

Cache mode 11.5 inches all on the 5in DD coil.

I remember reading a debate that a detector would only go as deep as the size of the coil.
I guess thy did not have a LTD



Edited 1 time(s). Last edit at 02/04/2011 02:46PM by gman.

Okay........I just tested the de/je/pf modes with 5" DD coil...........and...........interestingly.............they'll ascertain a 10.2" deep clad dime. I (somewhat) expected the 'je' mode to ascertain another 0.1" depth.........but no-joy.

.

So...

10.8" LTD

10.2" Standard F75

Hmmm...

Yes...........and THAT differential/delta was (somewhat) more than I expected. (((( The blessings of a "controlled" testing environment ... for resolute )))).

5" DD coil Benchtest - Dime 8.2" 0 disc 85 sens 4 tone

Look Normal For a T2 ???

In my red clay test bed I would have said that THAT differential was too small. I'm seeing a little over 1" in my dirt between DE and BP.

Tom, can you do an abbreviated test with the 5" DD running in CL? I'm having some success running in this mode moving Minelab slow. Of course, the TID is useless.

You know Tinfoil has been preaching to me for the longest time to put my 5" coil on the LTD.



" Installing the 5" DD coil on the F75 LTD.....and
> I can rotate my body 52-Degrees"

Yes, that's about right.....for the T2 and 5" coil combo.

As far as 'cl' mode = It'll ascertain another 0.2" on the clad dime......in Florida dirt. This would be 11.0".

I'm new to this forum, although Ive lurked for a couple weeks. My only regret is I wasnt lurking here a year ago to see what was really going on with the f75 LTD. I recently received an f75 se (w/boost etc) and all I can say is that I cant wait till more of this $%^% white stuff goes away ! Ive been a die-hard ML fan for nearly 15 yrs, and I believe this one could give the old ML a run for the money. In my initial air tests w/ the f75 my jaw somewhat dropped. settings were disc 4, sens 75, mode bp. I was able to air test a fairly worn SLQ at 12.5". WHILE this may sound "so so" to some, to me this is pretty darn impressive due to the power lines that run thru my back yard. There havent been many machines that Ive owned that can pull that feat off (f75 was still chattering at those settings) and Ive owned plenty of the big dawgs of the different brands. Granted the Numeric ID jumped alot, but I could still get that TONE, and thats what is important (to me anyway) If I can get the tone, and the pinpoint is true thats like saying if it walks like a duck and talks like a duck...
Now, I have a question. Ive heard a rumor that the original software release of the standard f75 was more chattery, but was less apt to false on nails or small iron (at depth) and that the newer f75's ie ltd's in boost mode, are more prone to falsing on nails. Has anyone had these findings ?
Thanks, and keep up the informative "stuff" LOL

The 'bp' boost mode will amplify some very faint signals; yet, I do not find it 'falsing' on deep iron more than the standard F75. If Grnd Bal is set incorrectly.......there can be PLENTY of false signals. But this holds true with most units. . . . . especially with the deeper iron responses.

Silversurfer wecome aboard , if you were lurking you probrobly noticed this forum unlike most, is about informotion plain and simple.
I would agree with your statfment . My original F75 was almost never fooled on iron. My F75 SE bost mode tricks me more often.
I picked it up late last fall , so not many hunting hours on it.
I can tell you if in boost mode and hold the red button it will revert to DE mode and that helps.
Posting on this thread . you must have read the 6 pages of great info here.
Any questions , just sing out and someone will help.

I'm not happy with my answer.

Let's try this:

You may have to adjust your Grnd Bal.....NOT to the mineralization of the dirt.........rather........to mitigate/minimize 'falsing'.....if the 'falsing' becomes excessive.

I know I have mentioned this before..... and probably in greater detail.

Thanks Gman, have you noticed any correlation in your conf meter being low, and/or your PP being slightly off center when being fooled, or is it truly fooling you ? IE... I had hunting buds that would dig square nails all day long .....for yrs on end with thier cz, but whenever I used mine it became appearant that it was most likely iron if the PP was off 1/2 to 1". Sometimes, I could even notice a difference in the "ping" of the high tone .( I ran a cz off and on for a few yrs too)
Tom , thanks for your modified answer LOL. Its something I'll have to deal with when Im running the 75 thru my test plots. I mostly bought this unit for the increased depth in tall grass/wooded/field areas that I like to hunt. Alot of these dont have much emi, but in the town type settings, It sounds like I'll be having to do some tweaking. If you find the link where you discussed that GB to tune out or mitigate falsing, please post it, Id love to have your insight on it.

Silversurfer i dont use the conf meter often as i hunt mostly old site so im digging anyway. I would say missing by a hair.
On the lower part of page 4 of this thread there is a great read on Freq shift.
I dont hit alot of EMI and would just dail it down a little. Not after reading Toms article on F1 - F7 shift.

Tom, can you describe how you test to a 0.1" precision?

Easy.........Broom handle (Dowel rod) cut to exacting length. The (somewhat) difficult part is......if the target is to be tested in the ground........the diameter of the dowel rod needs to be quite small....pencil diameter.....(for max dirt exposure)....and the coil needs to lightly 'touch' the dowel rod whilst sweeping.

Something in dire need of further clarification.....IRT 5" DD coil on the F75 LTD.

First, let me start with saying........I hunted a few fairly clean (non-trashy) areas/sites with the little 5" DD coil......where many targets were not masked. I was able to ascertain 10" and slightly deeper depths on coin-sized targets. Once again.....as long as there were no other targets in close proximity.

What appears to be a paradox......is the fact that the larger 11" DD coil will unmask targets to a greater extent than the 5" DD coil in target-rich/trashy sites.....with the targets being in the 7" - 10" depth range.

Targets needing to be unmasked (actually... extremely enhanced adjacent target separation conditions) that are in the 0" - 5" range......the 5" DD coil wins.....hands-down. Targets in the 5" - 7" depth range......and BOTH coils perform about the same (with a few exceptions). Targets beyond 7"......and needing to be unmasked...... the large 11" DD coil is the winner. You would think......because these targets are still within range of the 5" DD coil.......that it would still be the better of the two choices for unmasking. Not so.

There are many things that are happening......but a couple 'primary' reasons/justifications. First, the signal strength remaining at.....say 8"....for the small coil......is a very weak signal......and ANY other 'fleck' of a target in close proximity to a 8" deep target......and the 5" DD coils energy is fatally attenuated/shunted. For the 11" coil.........a target at 8" is still hardly a challenge.......and signal strength remaining at 8"....is still fairly strong. A small fleck of rust in close proximity to the 8" deep target will distort the energy......probably giving a incorrect ID.......but will still acquire the desired target.

Chose your coil wisely.......and accordingly to the specific site conditions.

For what it's worth, I start with the 11" to ascertain the environment in low DISC then switch to the 5" if it is a target rich (trash and goodies) site after getting what I can with the big coil.

silversurfer I found a dateless SLQ in the turf at a measured 11"+ of depth, and it was a classic four way repeatable hit. This was in an area heavily hunted by a multitude of ML from Exp2s - ETs. How they missed this I'll never know. What I've found out in the field is that the F75 LTD/SE in bp mode hits hard on silver quarters, even at depth. I've found 14 silver quarters since I've owned my F75 LTD. Unfortunately in my soil, it chokes up on dimes when they get any depth to the (over 6"). I hunt with a bunch of guys that run ML detectors, and while I'll find dimes in the 6-7" range when hunting with them, I've never found a deep dime, yet they manage to with frequency, and trust me when hunting with these guys I roll the dice on a lot of deep iffy targets -lol. Unfortunately in my experience almost all of my deep iffy targets have turned out to be junk (nails typically).


silversurfer Wrote:
-------------------------------------------------------
> I'm new to this forum, although Ive lurked for a
> couple weeks. My only regret is I wasnt lurking
> here a year ago to see what was really going on
> with the f75 LTD. I recently received an f75 se
> (w/boost etc) and all I can say is that I cant
> wait till more of this $%^% white stuff goes away
> ! Ive been a die-hard ML fan for nearly 15 yrs,
> and I believe this one could give the old ML a run
> for the money. In my initial air tests w/ the f75
> my jaw somewhat dropped. settings were disc 4,
> sens 75, mode bp. I was able to air test a fairly
> worn SLQ at 12.5". WHILE this may sound "so so"
> to some, to me this is pretty darn impressive due
> to the power lines that run thru my back yard.
> There havent been many machines that Ive owned
> that can pull that feat off (f75 was still
> chattering at those settings) and Ive owned plenty
> of the big dawgs of the different brands. Granted
> the Numeric ID jumped alot, but I could still get
> that TONE, and thats what is important (to me
> anyway) If I can get the tone, and the pinpoint
> is true thats like saying if it walks like a duck
> and talks like a duck...
> Now, I have a question. Ive heard a rumor that
> the original software release of the standard f75
> was more chattery, but was less apt to false on
> nails or small iron (at depth) and that the newer
> f75's ie ltd's in boost mode, are more prone to
> falsing on nails. Has anyone had these findings ?
> Thanks, and keep up the informative "stuff"
> LOL

Yet another bit of information I was not aware of regarding masking with the 5" coil.

One big plus IRT the learning curve of the F75s is how much knowledge is available because so many of the best dirt fishers, starting with Tom, use it and post tips and findings.

NASA-Tom Wrote:
-------------------------------------------------------
> Something in dire need of further
> clarification.....IRT 5" DD coil on the F75 LTD.
>
> First, let me start with saying........I hunted a
> few fairly clean (non-trashy) areas/sites with the
> little 5" DD coil......where many targets were not
> masked. I was able to ascertain 10" and slightly
> deeper depths on coin-sized targets. Once
> again.....as long as there were no other targets
> in close proximity.
>
> What appears to be a paradox......is the fact that
> the larger 11" DD coil will unmask targets to a
> greater extent than the 5" DD coil in
> target-rich/trashy sites.....with the targets
> being in the 7" - 10" depth range.
>
> Targets needing to be unmasked (actually...
> extremely enhanced adjacent target separation
> conditions) that are in the 0" - 5" range......the
> 5" DD coil wins.....hands-down. Targets in the 5"
> - 7" depth range......and BOTH coils perform about
> the same (with a few exceptions). Targets beyond
> 7"......and needing to be unmasked...... the large
> 11" DD coil is the winner. You would
> think......because these targets are still within
> range of the 5" DD coil.......that it would still
> be the better of the two choices for unmasking.
> Not so.
>
> There are many things that are happening......but
> a couple 'primary' reasons/justifications. First,
> the signal strength remaining at.....say 8"....for
> the small coil......is a very weak signal......and
> ANY other 'fleck' of a target in close proximity
> to a 8" deep target......and the 5" DD coils
> energy is fatally attenuated/shunted. For the 11"
> coil.........a target at 8" is still hardly a
> challenge.......and signal strength remaining at
> 8"....is still fairly strong. A small fleck of
> rust in close proximity to the 8" deep target will
> distort the energy......probably giving a
> incorrect ID.......but will still acquire the
> desired target.
>
> Chose your coil wisely.......and accordingly to
> the specific site conditions.


That is exactly why I stick with the 11" DD coil on the Omega and G2. The shallow stuff is gone or non-existent and what remains is in the 7" and deeper range and the smaller coils will not pickup the signa in most cases.

This is "somewhat" freq dependant. I would still love to see FTP give us the 5.75" concentric coil developed by Fisher for the Edge/CS to use on the 7.8 Khz Greek series machines. That coil gets very good depth and by nature of the 7.8 Khz freq should outdo the 5" DD by a long shot in exactly this scenerio.


Tom Z.



Edited 1 time(s). Last edit at 02/18/2011 11:30AM by Jackpine.

Cal_cobra Wrote:
-------------------------------------------------------
> silversurfer I found a dateless SLQ in the turf at
> a measured 11"+ of depth, and it was a classic
> four way repeatable hit. This was in an area
> heavily hunted by a multitude of ML from Exp2s -
> ETs. How they missed this I'll never know. What
> I've found out in the field is that the F75 LTD/SE
> in bp mode hits hard on silver quarters, even at
> depth. I've found 14 silver quarters since I've
> owned my F75 LTD. Unfortunately in my soil, it
> chokes up on dimes when they get any depth to the
> (over 6"). I hunt with a bunch of guys that run
> ML detectors, and while I'll find dimes in the
> 6-7" range when hunting with them, I've never
> found a deep dime, yet they manage to with
> frequency, and trust me when hunting with these
> guys I roll the dice on a lot of deep iffy targets
> -lol. Unfortunately in my experience almost all
> of my deep iffy targets have turned out to be junk
> (nails typically).
>
As more snow keeps peeling back, my finds have been increasing in my side yard, which has ALOT of local history (P.O., stage stop etc...) Ive pounded my ground with every machine Ive owned and my last few machines were pretty much digging ferrous only.... The f75 located 5 additional older brass/copper targets for me yesterday......its looking to be impressive, especially the response... oh wait, I see more green today ....gotta go ;-) haha