Rcpt Ack of F75 Ltd prototype

I like mine. Seems in AM BP 99 sens I'm getting around 17" on nickel. In 0 disc Bp 99 sens a dime airtest all the way to the first joint on my rod, looks close to 13", with good solid tone. The thing to watch IMO is sweep speed. That's what I notice the most comparing old vs new. Quietness 1st, Slower speed requirement 2nd.

TNSS, thanks for your reports on upgraded 75. I still haven't sent mine in because it is extremely deep in AM,where I hunt most of the time, because I fear that FT will just turn the power down and pronounce it "upgraded". There seems to be such a w i d e variance in performance of these upgraded machines. Some folks have had to send them back 3 times and they still lack the pre upgrade performance.How does your upgraded 75 compare to the old 75 in depth in Both discrim and AM? Thanks for your input.

Doc,
I feel my upgraded machine is every bit as good during airtesting as before upgrade and quiet as mouse. I believe in most rural settings machine can be run wide open in both disc and AM. I ran mine wide open 99 sens o disc Bp over 4 bar indicated soil, no static/burps/notta. The 11-14 version was the bad one. Mine is Jan Version. Best $159 I've ever committed to metal detecting period. Inside towns I estimate one should easily be able to run 85 plus sensitivity.

Doc, that's where I'm at also.

I just refuse to continue to feed people who refuse to check their work BEFORE sending it to someone who is counting on the senders performance to right THEIR product.

Hi,,,,Hey Doc & Ozzie personally I would not get mine upgraded simply because I think that it is quite possible that a non-upgraded machine might fetch big dollars in the future....It could possibly play out like the 1021 3D saga who knows?....I'm not saying an upgraded one is better or worse but I am saying once everyone gets their 75's upgraded how many non-upgraded ones will be left? In March it's all over as far as upgrades go besides it seems like a crap shoot right now....JJ

I haven't seen anyone complain about Dec or Jan versions. Only complaints I've read about are 11-14 versions and people who bought new machines. Seems some of the new machines were loaded up with the 11-14 versions, many possessed momma bug pinpoint problems and weak AM.

Just got my F75 back today from my second upgrade trip. No momma pinpoint bug and air tests seem on par with what others are reporting. I can get an all metal threshold waver with a nickel similar to Keith Southerns video demo. Might be awhile before I can do any real world tests to really know how it compares to my old firmware. Right now my thoughts are if you use your F75 in the AM mode most of the time I wouldn't worry about the upgrade or at least wait till last minute for more reports (NASA Tom we need you ). If you use disc mode most of the time I would go ahead and get it. Just my opinion...still not a clear cut choice

I MUST start somewhere...... in regards to the new F75 LTD2. This report is going to be incremental..... as I collect aggregate data. This has been long-term....... and more difficult than meets the eye.
First......... let me paint a bit of the 'difficulty' picture. With the initial onset, batch inconsistencies invalidated data. Incongruencies/Inconsistencies that would produce varying results each day. Now, the largest contributor for my prolonged delay is..... silent EMI. Sparing you the volumes of invalidating data.............. finally; some solidified data has emerged. Multiple F75 LTD2's....... have produced parallel end-resultant data.

Let's start with this: ONLY the ID mode, 9.0, 11" elliptical DD coil, Sens 99, Disc '0'. Remember....... the data provided below is from a batch of PRODUCTION RUN units. I can (nearly) say..... disregard previous LTD2 (especially proto units) data.

Nutshell........... utilizing only a clad dime in Florida low-mineral (primarily silica/quartz) dirt:

bp = 11.7"
cl = 11.8" (Exceptionally 'delayed' audio response)
je = 11.2"
pf = 11.2"
de = 11.1"
bc = 10.1"
FA = 9.8"

And this nominal median averaging............ over a period of months...... worth of aggregate/collected data......... during multiple atmospheric/EMI conditions........... and................. with different F1 - F7 freq selections. It has been a long road of dissection ....... for reasonably solidified data. Selecting different tone options is primarily a 'user preference'...... and hardly affects depth/performance. When invoking the 'boost process' modes..... many times...... it can audibly be heard that the LTD2 is imminent of ....... and right at the threshold of inducing EMI.
Remember...... it is still a F75....... and nearly all other (old) provided data..... still stands.
I will provide 9.1 data...... as aggregate data solidifies.
I will also provide all-metal performance in time.
Then........ 5" DD coil data.

Now....... with hundreds of hours of use...... I can safely report nearly a 85% reduction in EMI in 9.0. Switching to 9.1 does add a bit more EMI mitigation.

It is more difficult to see any form of pronounced depth/performance/gain whilst Disc is 4, 3, 2, 1 or 0......... and the subsequent Disc of 20 and above. It still exists; yet, is more subdued.

What I am still having difficulty ascertaining concrete data is..... measuring performance gain/loss between 1N audio.............. and FA process. (Yes, you can invoke both). 1N does give a substantial order-of-magnitude "fatigue reduction" in carpets of nails relic hunting capacity. FA process is extremely fast, and has marked performance gain providing enhanced adjacent target separation characteristics. This is to include hunting in carpets of aluminum trash and/or hunting carpets of nails. This process is extremely fast; yet, does not 'unmask' in it's true semantic definition.

FA certainly takes getting use to. For instance....... a clad dime at the 9.0" to 9.8" depth in clean dirt...... is merely a slightly elongated audio 'tick' (click); yet, to the astute/tuned ear...... still discernible/intelligible.

So far........... in a nutshell............ it's an enjoyable detector to use. ((( I hardly realized how much steroid/overdrive/EMI/high order-of-magnitude "fatigue factor" tolerance I had developed whilst hunting with the older generation F75 LTD...... and still do. )))

Some more good data Tom. Do the upgraded units while running in Bp process still yield the extra coil to dirt airgap vs say de process like the older F75LTD units??

((( TNSS = You hit the nail on the head. About 60% of the air-gap forgiveness is gone. )))

Thanks Tom, looks like the upgraded units are indeed not as deep. But this takes into consideration a user with older unit is in a low/non EMI environment. I feel after using my upgraded unit in the sites I've used it thus far, the unit provides more usable depth while using disc. I'm not an AM hunter. And it would follow I'm thinking your future "test" data will reveal the AM is not as deep as the older as well. Look forward to your future data.

"about 60% of the air-gap forgiveness is gone"---Does this translate to a REDUCTION in depth? Thanks Tom for your reports.

A BIG thanks Tom for wading through the dissimilar units and providing us with some much needed insight into the F75 Ltd2.

For me, I'm happy to let March 1-st pass by without a nagging thought in the back of my brain.
I'll enjoy my less enjoyable F75 Ltd :-)

However,... all this talk about EMI has made me much more aware of it's existence,...!!!

I dare say I'm coaxing the flavour of the moment to better ID at depth, happy with my F19

HH
Johnb

Tom,

I noticed when I had my 11-14 upgraded machine, FA mode was all but useless in the field. It simply blurred the audio together too much for any intelligible data to be derived. Fast forward a month later and testing a 1-15 upgraded machine, identical settings (9.0, FA, 0 disc, 99 sens, 11" DD) and in the identical sea of iron, FA mode was now working very well, and I was able to pull a number of previously undetectable conductors from a spot written off. Unfortunately nothing great (shotgun hulls, harmonica reeds, riffle shells, etc), BUT any one of these could've easily been a coin or button. One thing that I noticed about the FA mode is that at first when you're detecting in heavy iron, you may only hear a peep of a different non-FE tone, and then after stopping and analyzing it, you can work the tone up to a (semi)repeatable non-FE tone.

I'm very interested to see what your take is on using FA mode with the 5" coil. Also what about the 6" coil?

One point that I'd like to mention, is that I've seen a few posts regarding the difference between disc 0 & 1+ when in 9.0, BP, 99 sens, whereas with a disc setting of 1+, deep fringe depth non-FE targets will TID as iron, whereas in disc 0 they will positively ID as a non-FE target. What's your take on this?

Thanks,
Brian

Scoop johnB--I'm with you in letting 1March go by without a nagging thought in my mind. I reread Tom's entire post on the F75ltd,Racer post,and the abbreviated F75/2 post and I am convinced that I would rather learn to tame this stallion(nonupgraded 75) rather than have a gelding that no matter how long my spurs he ain't got the horsepower. And if all else fails I'll just get me a Racer.

Hi,,,,Thanks Tom I love your most informative review/tests on machines....A 60% air-gap forgiveness (loss) is not good especially if you are hunting an uneven farm field etc....On the other hand a quiet running machine can be very beneficial and more enjoyable to use....I guess you can't have your cake and eat it too.....JJ

More data to be documented.

Now let's talk 9.1. All of the below data will be exclusively 9.1 ...... and you can compare it to the (above..... exclusively) 9.0 data.

ONLY the ID mode, 9.1, 11" elliptical DD coil, Sens 99, Disc '0'.

Utilizing only a clad dime in Florida low-mineral (primarily silica/quartz) dirt:

bp = 11.4"
cl = 11.6" (Exceptionally 'delayed' audio response)
je = 10.6"
pf = 10.6"
de = 10.4"
bc = 9.8"
FA = 9.7"

These numbers are not quite (but almost) 'linear' to the 9.0 numbers. . . . . just a bit less (overall) depth.

In bp process mode..... there is a bit of a lag/delay in audio response to the detected target. If you have a standard F75 SE/LTD....... this audio lag delay would be akin to ...... somewhere between the 'bp' and 'cl' modes. It does take a bit of learning-curve time to get accustomed to. This 9.1 rev....... is 100% DST....... and appears to provide approximately 7% more EMI mitigation.

bp & cl modes present a 'time lag' delay in audio response to a detected target. [[[ bp & cl audio lag's ]]]
FA mode is the exact opposite (both 9.0 & 9.1). The audio report is quite premature. In fact...... BEFORE the target is under the coil.... the detector reports the audio response. [[[ FA audio response leads ]]]

On ANY F75 (old or new).......... the more you lower the Disc....... the stronger the propensity for the detector to ID non-Fe targets more accurately. This is also true with the T2/F70 & Makro Racer.

If you can keep the coil close to the ground.......... will easily ascertain the depths listed above (in Florida low mineral dirt). If you need to have a 5" or 6" air-gap above the ground....... THEN there is a greater loss in depth/performance....... as compared to the noisy F75 SE/LTD's.

So far.......... I have yet to find need/purpose/function for 9.1. The forfeit of a bit of overall depth/performance coupled with a mild increase in audio lag...... is somewhat disconcerting. On the contrary........ 9.0 is very applicable/usable/value-added.

Zero difference/change in battery consumption on LTD vs LTD2.



Edited 1 time(s). Last edit at 02/24/2015 11:53PM by NASA-Tom.

So Tom, this leading audio in FA 9.1. Would you consider`this better or worse at separating vs the FA in 9.0?? Or maybe better asked, do you see any detecting advantages using FA 9.1 vs FA 9.0???

The leading audio response is applicable in both 9.0 & 9.1.
The FA mode .......... of all the modes........... is the mode that has the highest propensity/vulnerability for EMI. There is still a fairly major 'value-added' in the use of FA mode in high trash (aluminum, or carpets of nails) areas.

Something worth reiteration: Although there is a few percent of overall depth reduction on the LTD2 platform......... it is several hundred percent more intelligible. . . . . . . substantially less fatiguing . . . . . . can open up doors in (previously EMI shut-down) areas . . . . . . and is more suited for the general detectorist (that is not wanting to be in hyper-steroid mode) that can be encountered with the non-DST LTD/SE F75.

Thanks Tom, my mistake I reread your post and indeed see 9.0 FA and 9.1 FA audio response leads in both.

My mind is made up. I think I'll stick with ' hyper-steroid ' and my deep 'all metal' unit.....Not going for the supposed up-grade. In the few areas where emi is bad, I'll just grab a different detector.

Hi Tom,,,,thanks again for the added data.....If you was to drop the sensitivity down on a non-upgraded 75 to eliminate the EMI,would it equate to the upgraded 75's depth or be close to it?....Of course all of the other settings are set the same on both of them while doing this ...JJ

jimmyjiver Wrote:
-------------------------------------------------------
> Hi Tom,,,,thanks again for the added data.....If
> you was to drop the sensitivity down on a
> non-upgraded 75 to eliminate the EMI,would it
> equate to the upgraded 75's depth or be close to
> it?....Of course all of the other settings are set
> the same on both of them while doing this ...JJ

Exactly what I was going to ask. I have an F70 that can be dialed down via sens, thresh, and frequency shift usually to mitigate the EMI, but I've been thinking of upgrading to an F75 LTD2 which I believe only has adjustable thresh in all metal. The answer to JJ's question would be significant in making my decision on the upgrade.

Anyway, thanks for the testing and information, Tom. I always look forward to your informative posts and threads such as this one.

Tom

Thank you for taking the time to gather this information and pass it on to us.

NASA Tom and others, I have a question for you. I am thinking about buying an F 75 with the upgrade. So I have all the "bugs and kinks" been worked out in the upgrade from version 12–14 and forward? I have the option to purchase a 12–14 model with the DST upgrade and I'm curious what your thoughts are on this purchase?

Thank you in advance!

Bubba

ok I am lost or maybe I am lost. So on the old F75 you where able have your coil higher above the ground in Bp vs De mode but would not that just come from extra depth. Sorry just a little confused. D

tnsharpshooter Wrote:
-------------------------------------------------------
> Some more good data Tom. Do the upgraded units
> while running in Bp process still yield the extra
> coil to dirt airgap vs say de process like the
> older F75LTD units??

Bryanna - Nebraska

Current - New to me but not new MXT Pro and T2 SE2 - Previous Minelab Sovereign GT, Minelab Safari, Whites DFX, Whites Eagle Spectrum
Smile its a good for you!

Bryannagirl,
You're not lost. When boost was introduced to the F75 platform 2 things happened. First the coil to ground distance was infact increased. The tones provided by targets were elongated a bit as well. Going from memory, Tom tested initially and posted no overall in ground depth gains going from old f75 to new f75 with boost with bp process engaged. Later I believe he determined in his soil, a clad dime was detectable to a depth of .2 inches more depth. So there was it seems a small bit of depth gained using the Bp process vs the old. Now comes the upgraded F75 units. I have used mine and dug some deep targets. I felt coil height was not as forgiving as before with old F75 with boost. This is what prompted me to ask Tom about the coil to ground distance performance on the upgraded F75 units.

Strange sounding I know, a detector to yield more coil to ground detecting distance performance, yet it doesn't roll fully into the inground detecting capabilities.



Edited 1 time(s). Last edit at 02/25/2015 03:28PM by tnsharpshooter.

And Bryannagirl, since I can't edit. There was additional coil to ground air distance achieved on the F75 units with boost BP process. Something in the order of 3". This roughly 3" gap has been reduced with the upgraded units using Bp process. Tom's report says 60 percent reduction.

TNSS - thanks that is odd you would think detecting distance is detecting distance - I could see how a person hunting on non groomed areas would miss the 1.5 inches of swinging height buffer the BP mode provided prior to the current upgrade. Most detectors do not give you much buffer at all at least that has been my experience.

tnsharpshooter Wrote:
-------------------------------------------------------
> And Bryannagirl, since I can't edit. There was
> additional coil to ground air distance achieved on
> the F75 units with boost BP process. Something in
> the order of 3". This roughly 3" gap has been
> reduced with the upgraded units using Bp process.
> Tom's report says 60 percent reduction.

Bryanna - Nebraska

Current - New to me but not new MXT Pro and T2 SE2 - Previous Minelab Sovereign GT, Minelab Safari, Whites DFX, Whites Eagle Spectrum
Smile its a good for you!