Rcpt Ack of F75 Ltd prototype

On the blue dot target, stock coil or 5"coil?

This was with the stock 7-11 coil.

....I would not (necessarily) call the F75 a micro-jewelery hunter. The older F75 will detect the blue dot to approx 1/2". The Ltd will acquire it at nearly 1". THE GOLD BUG-II WILL ACQUIRE THIS BLUE DOT AT 4"! That's a BIG difference. BUT, you certainly can find smaller targets with the Ltd. vs nearly ALL other detectors.

Tom

So as to keep things deliberately consolidated on this thread.

....I have been struggling for a few simple answers for quite a while now... regarding Ltd vs. F75. I am wanting to know: "What control panel setting on the new Ltd (((whilst in the new 'bp' mode))).....is equiv to the older generation F75 w/max'ed out settings whilst in PF/DE mode(s).....and also 'JE' mode. I would love to be able to say that the Ltd with a Sens of....say.... 63 and a Disc of....say.... 4 is equiv to the older Gen F75 in a wide-open absolutely max'ed out set-up config. BUT... I CAN NOT FIND THE ANSWER becuase of too many variables in the dirt. There IS no answer. From target-to-target with varying size/shape/composition/conductivity etc.......there would be a DIFFERENT setting on the Ltd that would equate to the same performance ...with the older F75 always being completely max'ed out.
I have finally come to the conclusion that a 'standard' needs to be established. I NOW know what that standard should be. I've hinted/tested/toy'd/alluded/mentioned ... but not quite DIRECTLY "finalized" and justified the answer.....until now. The pinnacle test-standard for the F75 & F75 Ltd is a Type-1 U.S. $1 gold coin. It is a very small coin.... and is of exact/pinnacle conductivity resonance for the F75 & Ltd; primarily due to operating freq. This is a very small coin to most all detectors.....except the F75. The F75's detecting abilities will detect this target as if it is a fairly large target. Utilizing this target as a 'test-standard'..... will NOW allow for a base reference for which measurements can now be ascertained/conducted and with proper validity and accuracy.

Did I lose anyone?

Tom



Edited 1 time(s). Last edit at 11/08/2011 12:47PM by NASA-Tom.

well start the testing but in Calif dirt I can run a lower sens about 62 and get more depth and a quiter running detector...in BP with the LTD. I had an air gap on a dime that was five inches above the ground and four inches deep so nine inches I can't remember having been able to do that before... The same settings with the 5DD and I didn't think my machine was turned on...it was so quite...

LowBoy

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If you don’t dig it, then how are you going to know what you’re missing!
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Tom, why not test two dissimilar conductive standards that are more familiar to most hobbyists...such as a nickel and a silver dime? The silver dime does not have the ideal conductive resonance, but it does closely reflect real world coin hunting objectives.

It seems that I've read here or on a different thread that one difference between these units is that LTD will give a lengthier signal response to fringe depth targets. Search environs where ground noise/chatter can be the result of many sources, a unit's further capability to identify some of those fringe target noises as actual discrete signals and present them as such to the operator...should also be considered in any test measurement. Why? Because it is the practical equivalent of ascertaining more depth despite whether EMF actually penetrates any deeper in a given soil. Or more succinctly, a tick response at 12 inches is not equivalnet to a full width signal response at 12 inches, especially over noisy ground...despite each example acquiring the target at 12 inches.


As a minimum, the LTD test results should incorporate a qualitative insight/observation on to each target depth number. For example, a rating system of A= good lengthy signal, B= noticeably better signal length than 1st gen75, C= similar to 1st gen75 signal...or some other grading system that addresses this important feature on the LTD.

On the other hand, maybe in answer to your question "Did I lose anyone?" my response could have been summarized with "Yep...me!"

Jim.

Jim,

I have given serious consideration to using a US nickel as a test-standard; however, there is a MUCH greater differential in performance between F75(Ltd) vs. all other detectors whilst using a MUCH smaller target/standard. Yes, a nickel is a much more common (and comfort zone) target that everyone can relate/identify with...... but it would under-rate a primary factor of where the F75 truly starts to shine.........................and that being....MUCH smaller relic-like targets. Folks are starting to find targets that have never been found before.....or only in extremely small volumes.............,,,,,,,,,,,and now, finding them AND at formidable depths!

Tom

Fair enough statement Tom, I understand your rationale. I'll look forward to your results. Should the test data indicate a significant (what will "significant" represent?) improvement responding to low conductive, relatively small targets (in this instance the $1 gold coin)...otherwise in concert with a minimum of 1st generation F-75 capabilities...that's a unit I'll doubtless acquire. Still though, I would be interested in reading your assessment of the LTD's signal length compared to F-75 for the test target at deeper depths. In any event, its all good stuff...with thanks Tom...

Jim.

"CL PROCESS"/(mode)

This weekend, I performed extensive testing of the CL mode.....and at a few different locations. Conclusions/Summation:
The "CL" mode is only for medium-trash content (preferably less) areas. This is to say.... it is useless in very trashy environments. The clock-speed/recovery between targets is too slow..... and rightfully so.
In areas that are somewhat low in targets/trash, the "CL" mode is deeper. Exact depth gains vary.....as to be expected......depending upon conductivity & size of object. The "CL" mode has a stronger affinity for larger targets....... lending a greater depth gain (vs. any other mode). You must be warned.....the audio report is quite a bit delayed (very noticeable)...... from when the coil passes over the target vs. when the audio report is heard. In MY soil..... deeper targets were better detected with the coil scrubbing the ground. Other types of soils..... and the electronics my perform better with a few inchs air-gap above the ground.
I did manage to find some highly desirable relics in the 'CL' mode..... that the 'BP' mode would only produce a audible 'tick' for a response. I can confirm the 'CL'mode is deeper on certain targets. Two of the targets were .69cal musket balls (circa 1851).
What's interesting is; Whilst hunting in 'BP' mode ...... and locating 'fringe depth' targets......,,,,,, then switching back to standard/old F75 modes (pf/de/je).... and these "BP"-fringe targets would then produce only a short duration audio 'tick' of a report. SAME EXACT THING with certain "CL"-fringe targets........then switching from CL back to BP....and a audible 'tick' of a report would ensue. (((Switching from CL to pf/de/je modes..... and these "CL"-fringe targets were complely undetectable))).
There may need to be a line-in-the-sand drawn for a unit-of-measure large "TEST-STANDARD" target to be selected.....for a standardization of gauging/measuring depth-gain performance of CL mode vs. any/all other modes. A .69cal musket ball or .58cal Minie Ball may be a good start.......... but I believe the test-standard may need to be slightly larger.
I will say this.... as I did confirm this thought in the real world; A small cuff-button at fringe depth ...could be just as easily detected in CL mode vs. BP mode. No gain/loss in depth with a fairly small target in CL vs. BP. Now....PF/JE/DE modes....and the audio response on this exact target was just a audible 'tick'.

DE/PF/JE modes are for highly trashy areas.
BP mode is for fairly trashy areas.
CL mode is for moderate/low trash areas.


Plenty more testing to perform!

Tom

"As more time elapses.....it's really starting to sink-in ...about those 141 non-ferrous targets being found behind the previous Gen F75. A true feat. I'm certain of my previous abilities having 'sanitized' this exact location with old Gen F75."

Your sanitized are with the Gen F75 was maxed out right?
Sen 99
disc 0
tone 1
JE

Yes.... but with one minor correction to your settings in question. Tones was on '4'. Any time I am running Disc at '0'....... I'm in a multi-tone option. Old Gen F75 or the new Ltd.

Great report

LowBoy

TAKE A LITTLE TIME KICKBACK AND WATCH SOME OF MY DETECTING VIDEO'S BELOW ON YouTube

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If you don’t dig it, then how are you going to know what you’re missing!
How can you have your pudding if you don’t eat your meat!

I have been remiss on providing certain info. After a hard-core detecting reiteration/experience.... I have positively verified serious performance gains with low EMI vs. extremely low EMI...... and this is in the real world. I have witnessed/experienced/verified this with the T2 several years ago.... then with the original F75...... and now with the Ltd. This should seem/be 'common sense'... but well worth a write.

Several weeks ago, I reported finding 141 more non-ferrous targets in a ...beat-to-death.... small area with the new Ltd. ,,,,,,, I went to the exact same spot a few days ago to try one additional experiment with the new Ltd. The last time I hunted there...and found 141 more non-ferrous targets...... I could run the Ltd wide-open w/Sens on '99', Disc '0', 'bp' & 4-tone. There existed a moderate amount of EMI when the coil was stationary...and not flat/parallel to the ground. Whilst sweeping the coil on the ground......the EMI went away.... and 141 non-ferrous targets were located. NOW...............fast-forward to just a few days ago. Exact same spot. I set up the detector to try the 'cl' mode......and noticed that NO EMI was present. Immediately, I switched over to 'bp' mode..... and STILL no audible EMI. . . . . and this is w/Sens on '99', Disc '0', 'bp', 4-tone.....everything max'ed out.......AND,,,,THIS IS WITH THE COIL IN THE AIR AND STATIONARY. Because of this.... I decided to cancel my intent to try 'cl' mode .... at least for a while...... and hunt in 'bp' mode. Something seemed wrong with the detector....as if Sens was nearly zero....and the unit was operating at a severely reduced performance capacity......due to such low EMI. Sweeping the coil.....and in the exact direction/footprints as from when I had located 141 more non-ferrous targets......and my suspicions would instantly be invalidated..... as I found ANOTHER 92 more non-ferrous targets..... in this exact same location. Low EMI vs. near-zero EMI made a tremendous difference. Percussion caps were detected down to 12". I've never seen this type of performance before.

It's in the finite details.

Tom

You can bet "they" are working on it.

Sounds to me that you cleaned the ground the last time you went out and by doing so this time your machine ran quite. We did the same test and found targets that were more bits of copper and lead...a few relics of interest...the next time we hunted our machines were very stable and I had to grab the pinpointer to see if my headphones were working.

I noticed that I was digging deeper tergets deeper then I am use to digging...and they were relics...This machine workd differently then the older F75 becaause in DE mode the machine ran quite also. As I have said wet ground really makes my machine freak out but dry ground really makes this machine more stable.

LowBoy

TAKE A LITTLE TIME KICKBACK AND WATCH SOME OF MY DETECTING VIDEO'S BELOW ON YouTube

[www.youtube.com]

If you don’t dig it, then how are you going to know what you’re missing!
How can you have your pudding if you don’t eat your meat!

I recently had a very similar experience with my F-75 (not LTD). There is turn of the century house nearby and the first three or four times I hunted this location I ended up turning the sensitivity down due to significant EMI. I was able to pull quite a few old coins including some early 1900 silver and also some nice relics. On my last trip to this location I turned on the F-75 expecting to deal with the EMI but much to my surprise it was totally GONE! Just like Tom, I was certain there must be something wrong because the F-75 was uncharacteristically silent even with everything maxed out! However, once I checked my setup I realized that everything was functioning normally. I ended up having one of the most productive days that afternoon due to the absence of EMI. I have been back several more times; however, whatever was turned off that day seems to have been turned back on. I still have no explanation for what happened that day but it sure was nice while it lasted.

Leo

I'm glad you guys are experiencing this exact phenomenon. There are many factors that cause EMI...... but you can surely see the bottom resultant.

Stupendous depth/performance differential between standard F75 vs. Ltd whilst testing with U.S. one dollar Type-1 gold coin. The Ltd is extremely conducive to relic hunting due to it's performance gains with low conductors. I'm still trying to resolve a couple of 'variables'.....trying to convert them into 'constants' so as to scientifically acquire concrete numbers.....so I can share.

Incomplete test results as follows:

Test standard (the target): A U.S. $1 Type-1 Gold Coin (1849 - 1853).
Florida inert dirt.
Since gold produces no halo.....no dirt-time required.
----------------------------------------------------------

Buried 8" deep. Settings: Sens '90', G.B. '90', 4-tones & DISC '5'

pf/de = 8"
bp = 8" + 2.1"airgap
cl = 8" + 4.0"airgap
----------------------------------------------------------

Buried 8" deep. Settings: Sens '90', G.B. '90', 4-tones & DISC '4'

pf/de = 8" + 0.1"airgap
bp = 8" + 3.5"airgap
cl = 8" + 4.5"airgap
----------------------------------------------------------

Buried 8" deep. Settings: Sens '90', G.B. '90', 4-tones & DISC '0'

pf/de = 8" + 1.2"airgap
bp = 8" + 3.7"airgap
cl = 8" + 4.8"airgap
----------------------------------------------------------

Buried 8" deep. Settings: SENS '99', G.B. '90', 4-tones & DISC '5'

pf/de = 8" + 0.3"airgap
bp = 8" + 2.4"airgap
cl = 8' + 4.2"airgap
----------------------------------------------------------
----------------------------------------------------------
----------------------------------------------------------

BURIED 9" deep. Settings: SENS '90', G.B. '90', 4-tones & DISC '5'

pf/de = no joy
bp = 9" + 0"
cl = 9" + 2.1"airgap
----------------------------------------------------------

Buried 9" deep. Settings: Sens '90', G.B. '90', 4-tones & DISC '4'

pf/de = no joy
bp = 9" + 0.6"airgap
cl = 9" + 2.7"airgap
----------------------------------------------------------

Buried 9" deep. Settings: Sens '90', G.B. '90', 4-tones & DISC '0'

pf/de = no joy
bp = 9" + 0.8"airgap
cl = 9" + 3.0"airgap

---------------END OF STATUS THUS FAR-----------------

I wanted to boost Sens to '99' for the last set of tests......but EMI became an issue. The data above is fairly concrete; however, any time that Disc was dropped below '5'....... ""some"" EMI would ensue. This will reduce performance. EMI is one of the variables that I attempted to mitigate....attempt to make it a constant.
Some comments:
The two largest performance gains are when Disc is dropped below '5'....and when any one of the new modes were selected (ie dp or cl). WORD OF CAUTION, , , The 'cl' mode data above looks very impressive......... IS very impressive; HOWEVER, REMEMBER.....this mode can only be utilized in low trash-content areas.

IF IF IF..... I ever find time & location where EMI is near zero, I will bury the one-dollar gold coin at 10" deep and invoke Disc '0'.... and see/report the results. I predict the results will be stupendous.

All of the results above are MUCH more pronounced/impressive in EMI-free air-tests. This very small gold coin is a medium-size target in the pf/de mode. Once 'bp' or 'cl' mode is invoked....the U.S. $1 gold coin is viewed by the detector as a large coin.

Of note: Whilst performing the above tests..... the audio response whilst in pf/de mode were very short audio reports..... almost as short as a mid-tone click/tick. Whilst in 'bp' or 'cl' modes....the audio length reports were normal/full length audio responses.

For some folks; the data provided above may appear to be 'only moderate gains' whilst comparing 1st Gen F75 to the new Ltd; however, in real-world usage... the above results equate to tremendous improvements/success.

It is my STRONGEST recommendation that any serious relic hunter of whom owns a Ltd... should acquire a TYPE-1 U.S. $1.00 gold coin.... and preferably NOT a 1853..... as this was the most counterfeited (by China & Soviets) year coin. This coin is the most perfect representation of a test-standard for the T2/F75/Ltd due to it's size AND conductivity. Yes, a tiny (Size 2) 10Kt WHITE gold baby ring could suffice....... but a 'standard' needs to prevail.

Tom

...........also, this U.S. $1 TYPE-1 gold coin will ID as a '24'..... and it'll bounce on the ID scale a bit if it's not perfectly flat to the coil.

The reason why the Ltd is catagorized as a World-Class relic hunter is exactly due to the above results; extreme performance to low conductors.
IRT zinc/copper/silver coins (much higher conductors)..... the new modes show virtually no increased performance levels.

I know there are an infinite number of "what-if" scenarios that people might want to see, but I'd like to see the quantitative measurements of the LTD in BP and CL at very low sensitivity settings, such as 50.

I wonder if the apparent audio improvement is related to the type of dirt under the coil???

Tom,

I am curious how a disc of 20 or 21 would affect the depth. Please try this on any future test.

Thanks
Fred

All of the above recorded results are nearly matching my expectations...... except the fairly large gain difference between Sens. '90' and Sens '99' at Disc '5'.
------------------------------

On this U.S. $1.00 TYPE-1 gold coin, I did perform a distinct comparison of modes with following resultant:

pf/de Sens '90' is equiv to bp Sens '50' with all other settings the same (Disc '5', 4-tone, G.B. '90') on a 8" deep TYPE-1 $1 gold coin.

Also, I tried Disc settings of 18, 19, 20, 21 & 22......and found NO performance gains on the low conductor $1 gold coin..... and the same resultant on a high conductor clad dime.

It is going to be difficult to find a EMI-free location to test performance with everything wide open; Disc '0', Sens '99', 4-tones for the 'bp' and 'cl' modes.

YES, dirt mineralization content will alter/change all of the above data; hence, the importance of your own test-garden.

For air-testing a TYPE-1 $1.00 gold coin..... use a dowel rod. I used an old broom handle...... and cut the wooden handle into different lengths for testing purposes. Tape the coin to one end of the wooden stick using non-metallic/non-electrostatic tape.

Tom

Another hard-bought head-to-head comparison utilizing TYPE-1 U.S. one dollar gold coin:

'bp' mode/Sens '87'/Disc '5' is ~equiv~ to 'pf' mode/Sens '99'/Disc '0'.

There is a "World-Class" difference if you change 'bp' mode/Sens '87'... Disc to '4'. (((And obviously greater performance if you lower Disc even more....and/or raise Sens to higher settings))).

THE EDUCATION IS: IF YOU CAN TOLERATE A BIT MORE IRON AUDIO RESPONSES.....LOWER YOUR DISC!

Tom

That is interesting.

Because I read in another (2007) test of the regular F75 (airtesting on a Georgian Penny):

Difference Sens 85 compared to Sens 90 = 0.5 inch
Difference Disc 5 compared to Disc 0 = 4 inches!

If you would take these numbers and would add these gains to the F75 LTD,
you would end up with a 4,5 inch improvement of depth compared to F75 Standard.
In an airtest that is, not in the ground obviously.



Edited 4 time(s). Last edit at 12/05/2009 02:42PM by Piscator.

I realize just now my post was not correctly formulated.
Actual depth gain in the ground would be a lot less probably, but still...
Its quite an improvement.

I'm curious to know if BP/Sens87/Disc 5 on the LTD gives you the same amount of EMI as the standard DE/Sens99/Disc0?

I get a lot of EMI here (there is no way I can run so hot) and if the LTD in those settings has significantly less EMI problems, that would be a tremendous gain here.
Did you notice any difference?

That brings up another question:

Does the F75LTD have a better/different EMI filtering logic?



Edited 3 time(s). Last edit at 12/05/2009 09:39AM by Piscator.

On this particular testing day.....EMI was fairly low. Low enough to not be able to properly gauge a differential between the two. And changing the settings ... changes the entire ball-game.

On the LTD ,,,, there is no engineering change for mitigating EMI; however, due to different time-sampling rate with the 2 new processes...... provides a non-linear boost in performance vs. EMI boost. In other words...... the amount of boost is greater than the volume increase of EMI......resulting in overall better end-resultant performance.

I do believe.........overall.........the LTD will give a better performance boost (vs. a standard F75)......even with some EMI,,,,,,,,,,............ and this is to say....with using more sensible settings.

Tom

ENGINEERING NOTE:

As technology advances.... IRT detectors that are more sensitive & deeper; there lies justification for the usage of smaller/more-focused coils. Currently, with the F75 LTD with standard/stock 7-11" DD coil..... as Disc is lowered in concert with higher Sens settings.... more targets are being 'lit up' than ever before. Headphones/brain become inundated with numerous additional targets. The phobia of using a smaller coil with it's 'perceived' intimidation-factor of only being able to search minute' amounts of ground.... becomes moot. As experienced detectorists are starting to realize the volumous amounts of masking & adjacent target separation failure that is incurred .... in most areas that we hunt.... utilizing smaller coils to 'light-up' more targets individually..... in the same amount of parcel..... is nearly an epiphany/eye-opener.
In more practical terms; A fairly deep/good detector with a standard concentric 8" coil ... may 'light-up' .... say, 14 targets in a 5' x 5' area. Using a older Gen F75 w/stock 11" DD coil .... may 'light-up' .....say, 22 targets in the same 5' x 5' area. The newer F75 LTD may 'light-up' .... say, 27 targets in this same area. And the reality is..................... a even HIGHER powered (more sensitive) detector with a smaller DD coil......BUT...... having the ability to go as deep as the 11" DD coil......... would then have the ability to 'light-up'......say, 45 targets in this same exact 5' x 5' area.
Moral of the story: A small-coil equipped high-powered detector..... would no longer give the perception of "inability to cover volumous amounts of property" ..... as there would be SO many more targets to individually select from.......and in a much more efficient fashion.
We've already had a serious dose/taste of this... via the introduction of the DD coil equipped F75...... going over areas that have been beat to death.....and adjacently separating out.... and 'lighting-up' more targets that we thought never existed. HOW DO YOU KNOW WHAT YOU ARE MISSING........IF YOU NEVER KNEW IT EVEN EXISTED. A smaller coil equipped detector that could be engineered to ascertain the same depth (or nearly the same depth) as the larger/standard coil...... would certainly "open our eyes again".

Tom

I finally had the correct conditions/opportunity to reverse-test the LTD. One of the biggest concerns with a new detector....(or new processes... in this case) .... is to know if it'll outperform the old modes (or old detector).......and.......if so....... will it be a 100% performance resolution....or some random number of a lesser percentage.

In short; I hunted a parcel of land that had never been hunted before (private property). It was of medium-trash content....... and mostly of nails/iron......a good test-bed. Many (34) non-ferrous 'keeper' targets were located. I hunted this parcel several times....and from several different directions......until no more non-ferrous targets were found. This was performed with the LTD in the new 'bp' process mode. Once complete.... I would now have the ability to place the LTD in the older 'pf' and 'de' modes..... and see if these older (and faster) processes (modes) would/could find anything behind the 'bp' mode of operation. And the answer was: NO more non-ferrous targets were located. I did not expect to ascertain/acquire a "100%" resolution/answer. This was only one test...... and with only one set of conditions. It certainly gives 'direction/bias'..... but I feel that the results may be different (slightly) with other conditions. IF the site was HEAVILY littered with carpets of nails..... the 'bp' mode may be a bit too slow to recover 'between' adjacent targets; subsequently giving the edge/lead to the faster process of pf & de.

I have already verified the 'cl' mode is useless in medium & high trash content areas........ as to be expected.

Tom

hi tom!
can we assume that ALL the non-ferrous targets were REAQUIRED with the "pf "de" modes of the f-75 ltd?..i'm a little unclear on that point!..thanks!

(h.h!)
j.t.



Edited 1 time(s). Last edit at 12/15/2009 04:40AM by jmaryt.

I dug all of the non-Fe targets.....BUT.......I did manage to switch over to 'pf' mode on the LTD.......just for my records/curiosity.......and found the exact same resultant.....as reported in a few other previous posts. MOST of the non-Fe targets were detectable (not all were at 'fringe' depths. keep in mind, this was a unhunted area)..... and a few were fringe 'clicks' for a audio response (in the 'pf' mode).

The final summation/point/conclusion being; 'bp' mode got all of the non-ferrous targets........ the 'pf' mode would have missed some.....and the confidence of running the 'bp' mode is fully instilled......for this (medium iron trash) scenario. There would be no need to run the 'pf' mode..... nor would there be a need to GO OVER THE SAME AREA AGAIN and find additional targets that the 'cl' mode may/could have missed......as the 'bp' mode validated itself. I (now) have even more confidence in utilizing the 'bp' mode over the older-model F75 modes. No need to go behind myself in a lessor 'pf/de' mode.

Tom