Rcpt Ack of F75 Ltd prototype

Observation/Experience =

For a couple of years ..... my 'gut' was telling me that a particular old school did not produce the correct ratio of nickels...... representative of the era. This particular school had a short-lived life-cycle..... with a pinnacle/banner year in 1940. This is to implicate that .... the most nickels were lost during 1940. A school lunch was 5-cents. If you lost your nickel....... you lost your lunch. Plenty of wheat pennies and quite a few silver dimes were found............ but not the correct ratio of nickels............... in fact....... hardly any. This place had been detected to 'completion'....... by me....... with a CZ. No more coins being found..... for the last several hunts.

This past weekend, I hit the area hard with the F75 LTD in 'bp' mode. Seven (7) nickels were found. All were Buffalo nickels. Nearly all of them were just a tad over 11" deep. In Florida inert soil..... this is not much of a challenge for a CZ or F75. This hunt was set on the premise of 'fact-finding-mission'.

Several lessons/things to be stated for the record. I found plenty of pencil erasers (nearly the same conductivity as a nickel)...... and plenty of other lower conductor implements. BUT........ when a nickel was detected......... the breadth/width/girth/length of the audio response was very broad........ obvious.............. representative of a solid, fairly large 'coin-sized' target.......... at depth. Delineable/differentiable with a high success rate. All of these targets were pin-point marked...... before any shovel hit the ground.

Conclusion/education = On a CZ platform....... all of the fairly deep nickels were conductively 'down-averaged'....... subsequently ID'ing as 'foil' or 'iron'.,.,.,.,.,.,., never once ID'ing as 'nickel' conductivity ..... and certainly never as a conductivity of something higher than 'nickel'.

On the F75 platform....... all of the nickels never ID'd correctly; yet, a distinct difference was noted. Each individual target/nickel ID'd anywhere from a VDI of 18.... all the way up to a VDI reading of 50. This is to say a continuous ID 'bounce' of foil, nickel, round-tab and square-tab. Most of the time...... the ID was above nickel conductivity. A distinct intelligible signature/trait of the F75 platform..... usable/value-added tuition.

This particular dirt has plenty of tiny iron flecks/flakes; which is the primary clue as to the mis-ID on both units; albeit .... different from each other. In this particular environment, the CZ will 'down average'....... whereas...... the F75 will 'up average' the ID.
Big difference!
What does YOUR dirt do? Knowledge = skillset = success!

TomD. I'm guessing you set up the cz, 0 disc max sens and the 75, 0 disc max sens also. Have a couple questions;

1- With the iron flecks in the inert soil, what did the fe2o3 on the 75, read?

2- Were the depth numbers/readings close to accurate on these nickels?

3- Or, did the iron flecks interfere with the depth numbers/readings?

4- Do you think the I.D. results would change, if the iron flecks were just above and/or just below the nickle?

5- Did the iron flecks broaden the signal? If there were no iron flecks, would the signal be shorter?

6- With zero flecks in your inert soil, would the units normally ID the nickle correctly at that depth?

Steve,

Your thought-process, questions & concerns are exacting/spot-on. I'm a little short on time...... but let me do my best.

First.......... the tiny iron rust specks/flecks/flakes are minimal......... the size of ground pepper from a typical household salt/pepper shaker........ and linearly interdispersed in 3-dimensional form/axis throughout the dirt. It would be like taking a bag of freshly popped popcorn and lightly sprinkling pepper in the bag........... then shaking the bag very thoroughly.

1. The Fe3O4 LCD meter ...... at most...... would read 2-bars (.03)

2. The LCD depth bargraph..... and the VDI depth readings were inaccurate; yet, indicated deep. Even the audio whilst pinpointing was very weak..... and in some cases..... zero pinpoint audio; yet, whilst sweeping the coil over the target whilst in regular sweeping/detecting ID mode....made for fairly easy/clear pinpoint ability....... and positive knowledge that a metallic target was present.

3. (Answered above).

4. This is where things become tuitionally interesting. The iron flecks were above, below, around each target. If the iron flecks were ONLY ABOVE the target......... as long as the 'volume/amount' of these rust flakes/flecks remained the same........... the resultant would remain the same. If there were a slight increase in volume of these tiny flakes............ then the target would become completely silently masked. No audio response. If there were slightly less iron flecks in the soil......... then the ID would become more accurate..... reducing ID bounce on the F75.
If the flecks were ONLY BELOW each target......... there would be virtually zero interference; with the end-resultant being the same as if there were no rust flecks/flakes. Much clearer detection of intended target...... much less ID bounce and no masking.
If there were zero iron flecks/flakes in the soil.............. a CZ (in Florida inert dirt) would positively ID these nickels as 'nickel' (with corresponding high-tone) to depths of 11.5". Beyond 11.5"....... and the CZ platform will 'ID bounce'...... usually between 'nickel' and 'high coin'. The F75 platform would up-average the ID; yet, present a more steady (reduced) ID span.

5. Yes. . . . . . somewhat. On the T2/F75 platform...... the 'squelch' is broke,,,,, opening the audio gate sooner..... and also delaying the 'closing' up of the audio gate (delaying squelch cut-off); resultant: a slightly longer audio response on the deep nickel.

6. (Answered in 4. above).

ALL of these (7 independent nickels) were out of detection range of the Deus/GMP.

More to say. Out of time!

Thanks Tom, for those complete easy to understand answers.

Hello everyone,
Tom , is this latest information applicable to the new F75 LTD 2 ?
Thanks in advance!

Most of it; yet, TOO preliminary to tell. And, I am still uncertain if this particular prototype is also close enough to the final production-run units; hence, my reservations in reporting/documenting......... especially in public/forum fashion.

Also........ It looks like many of Fisher's prototype testers are on this forum and are reporting 'some' differing resultants........ quantifying my reservations.

Of noteworthy mention (due to latest 'buzz'):

Of all the detectors available on the market today....... with 5" coil (or similar small coil size) installed. Whilst in 'bp' mode......... the F75SE/LTD with 5" DD coil installed............. as of current time........... is the deepest VLF detector on the open market. This is for 'medium' mineralization to no mineralization dirt.

So the f75LTD/SE series version 2 is not included???

I still only have a 3rd Gen Proto LTD2 at the moment....... and reserve final report.

Look forward to your findings.

NASA-Tom Wrote:
-------------------------------------------------------
> I still only have a 3rd Gen Proto LTD2 at the
> moment....... and reserve final report.

Definitely am looking forward to your findings.

I know what mine have thus far. I ran into the standard issues after upgrading my 2009 camo LTD and it's on the way back to FT, but what did as expected, work worked well IMHO.

NASA-Tom Wrote:
-------------------------------------------------------
> I still only have a 3rd Gen Proto LTD2 at the
> moment....... and reserve final report.

To quote Gravedigger Max from his youtube beach hunting vids : "STANDBY!"

HH
Johnb

Sooo, while I'm awaiting the return of my new (broken) F75, I have been doing as much reading as possible. It's hard for it all to soak in without a machine to try things out.

I have a question that may be way out in left field. From reading it seems that the highest performance levels would be with discrimination 4 and below or as low as you can get it.

My question is this. If the unit is set to 0 disc and then notch discrimination was utilized. Does the disc automatically default to whatever you chose for the notch setting or would you still benefit from the 0 disc setting? Say disc was set to 0 then 4-12 notched out. Would the disc default to 12?

I'm sure if it was possible everyone would be using it, just thought I would ask.

Thanks,

Kenny

Kenny............ yes, there is a slight loss in depth/performance whilst Disc is on '0' and 'notch' is employed.
Unless there is an extenuating circumstance........ I recommend against using any form of 'notch'.

Thanks Tom. I was wondering if there would be any difference (benefit) performance wise using the notch versus just turning the disc up higher? There comes a time in my hunts where I simply can not tolerate hearing everything and need to quiet things down. Would using the notch versus cranking up the disc would realize any performance benefit or is it the same game.

Thanks,

Keny

Question Tom.

What are your GB numbers in your soil that runs Fe/Co .03.?

Is there a direct correlation between Fe3o4 numbers and GB numbers or are there more things that affect GB numbers than the Fe/Co readings.

Reason im asking is my Fe3o4 numbers run the same as yours .03/2 bars or slightly less and my GB numbers are 54-56 using the 5" coil.

Not sure how fine/accurate scale ,lack of better term, the fe3o4 runs at and if mine and yours are the same if they actually represent the conditions as being the same. Mineral wise.

Just fishing I guess.

P.M.

Kenny........ It sounds like you need to adjust/config your detector to your specific site needs. I would not worry about a slight amount of depth loss....... especially if it puts you in the game......... and allows you to stay in the game for a much longer period of time. ie:

If you can only hunt for 7 minutes at 100% power/sensitivity/performance.
or
You can hunt at 97% power/sensitivity/performance for 8 hours!

-------------------------------------------------------------------------------------------

Pac man = The Fe3O4 bar-graph tells you the AMOUNT of mineralization.
The Grnd Bal ID numbers tells you the TYPE of mineralization.

There is virtually no correlation between TYPE of mineralization and AMOUNT of mineralization. If you have a certain amount of Fe3O4 of mineralization........ it will not dictate what type of Grnd Balance numbers you will ascertain.
In reality.......... the Grnd Balance number that you acquire is virtually unimportant........................ as compared to the AMOUNT of mineralization you encounter. You will have much better depth performance (and ID accuracy) when mineralization AMOUNT is low.

Well the light came on.

Thanks Tom

Tom I haven't seen you post much in regards to the new DST F75-2 & T2-2, so I find it interesting you're selling F75-2 "validated" machines (implies you must like it

At any rate, I am curious if you are also testing the T2-2? If so, any thoughts you can share on that machine? Anything the T2-2 is doing better then the F75-2?

My F75-2 is back to First Texas for round two of upgrades, but in the meantime I have a brand new T2-2 to lean. Never having used one, I was a bit surprised to learn that the audio tone and process modes are not mutually exclusive. Good way to force oneself to hunt in 2-tone mode using BP!

Even though my F7-2 had some issues after the DST upgrade, I'm VERY impressed with it's stability now when running BP with 0-1 disc at EMI infested inner-city San Francisco bay area parks where EMI has always been a challenge in the past. I do wonder if, even though the EMI is still present yet the F75 isn't audibly reporting it, if it's in fact taking a hit on performance?

HH,
Brian



Edited 1 time(s). Last edit at 01/28/2015 06:00PM by Cal_cobra.

Hi Brian,

I have posted a few scattered reports/findings on the F75-2......... but certainly not a full/comprehensive report as of yet. (Time constraints)! AND.......... I just received a final-production-run unit. I had (and still have) no intent on posting my findings on any of the prototypes...... as ...... their performance is quite different from the final production run units. (I do not have.... and have not tested a T2-2).

I will say this.... however:

These new DST units are substantially more EMI quiet.......... to the tune of about 85% improvement. They are now MUCH more suited for the general detecting community. More stable.

It appears the 9.0 mode is 80% DST employed.............. and DST 9.1 mode is the full/100% DST mode. Whilst in 9.1 mode...... the audio responses to targets are slightly elongated......... similar/somewhere between 'bp' and 'cl' mode.

Much more to follow.......... as experience accrues.

The T2v2 I have is pretty much like the 12/14 F75v2 ..works like it should just quiet...

its not quite as powerful as the F75v2..

Use to I preferred a T2 over a F75 because I could get the sens higher on a T2 around here so in real world hunts I found it deeper...

now that they are both quiet you can tell in real world hunts the F75 is a BEAST compared to the T2...nothing wrong with the T2 its just the F75 can finally be seen in the right light,.

Keith

keith!..can you detail as to HOW you have determined
the the f-75 2 is more powerful than the t2 v 2?..thanks!

(h.h.!)
j.t.

Quote
NASA-TOM
It appears the 9.0 mode is 80% DST employed.............. and DST 9.1 mode is the full/100% DST mode.

Hmm, this is opposite what Fisher writes on p.16 in their owners manual...

((( I know!! Yet, I impart real-world witness/experience resultant )))

NASA-Tom Wrote:
-------------------------------------------------------

> It appears the 9.0 mode is 80% DST
> employed.............. and DST 9.1 mode is the
> full/100% DST mode. Whilst in 9.1 mode...... the
> audio responses to targets are slightly
> elongated......... similar/somewhere between 'bp'
> and 'cl' mode.
>
> Much more to follow.......... as experience
> accrues.

Hey Tom,
Have you found any instance where 9.1 is preferred over 9.0?

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?

Tom thanks for your feedback. Your experience with DST 9.0 vs 9.1 is what I've observed as well, DST 9.0 is my go to mode. Will be interesting to see what FT does to my F75 on it's current visit there to fix the mama bug and a couple of other items that needed attention.

I'm getting ready for a small three day detecting trip over Presidents Day weekend to hit some old (for California) sites we've spent countless hours researching. One area is a revisit as it's produced two gold coins, two bust half dollars, numerous reales, numerous seateds, as well as some nice relics thus far. Then I have a couple of newly researched sites that we have not detected yet to check out, debating on taking the F75-2 or the T2-2. Probably will take both as my comfort factor lies with the F75, but I need to learn the T2 and it would be a good backup machine.

As they are similar, yet different, I wonder if going over a site with the T2-2 that was "cleaned out" by the F75-2 would reveal any new non-ferrous items the F75-2 missed?



Edited 1 time(s). Last edit at 01/29/2015 05:02PM by Cal_cobra.

Wayne....... I have yet to find a location where 9.1 was needed. In fact..... one area did induce some audible EMI..... and raising Disc to '5' and dropping Sens to 80 cured the EMI. No need to switch over to 9.1. ((( I did try 9.1 under these circumstances...... and the EMI was gone.... as long as Disc was on '5'. I could still run Sens on 99 ))).

Brian........ It's possible; yet, I doubt it.

NASA-Tom Wrote:
-------------------------------------------------------
> Brian........ It's possible; yet, I doubt it.

Tom I suspected that might be the answer. I suspect it may be well the other way around.

Eagerly awaiting more info for the F75 2. Fisher is being pretty closed mouth when asked number pretaining performance. I'm on my second NEW F75. All metal seems quite anemic with 10" on a nickel. So far no response. Was hoping to see your write up Tom so at least I would know what would be considered normal.

Thanks,

Kenny

I second that, as well. My F75LTD-2 is definitely quieter but not as sensitive. Air tests are similar to those reported but in my test garden 10" coins have become if'fie (am I hearing them because I know they are there?).
The AM mode is definitely poor compared to my pre-upgrade. The FA mode is weak (half the depth of BP) and I do not see any added separation abilities.
I, too, am waiting to hear Tom's report on the upgraded F75-LTD.

The question is: will I find more in the ground because it is quieter, even though it isn't as deep?

Regards,
Ken