Tom can you enlighten us on these questions

1. Have you tested the F75 and the stock coil in your test garden?
2. How did it respond to the dime at 12 1/8" deep?
3. How about the dime and nail plot?
4. Just how slow can you move the F75 in a real trashy area and still detect targets?
5. How does it do with the nail and rusted piece of metal and the buried dime?
Any final thought not in your compilations?

Good questions. Hence; the justification of a test-garden...... and,,,, hence, the beginnings of head-to-head comparison testing. You are the only person (thus far) to tie these two together (test garden & Brand-X detector)...... and ESPECIALLY the 'complex' target scenarios. This is the FIRST step that I perform..... before I even qualify a detector to make it to the next step........ that being; the real world. If Brand-X detector fails the test garden...... it does not qualify for taking it anywhere else.

1. Yes
2. I could write volumes on this one. BUT....... in short: On days where EMI is minimal/non-existent.... and I can use maximum settings; yes, the F75 will detect the 12-1/8" dime. ((( I cannot lift the coil off of the ground; scrubbing reqd ))). Interestingly; if I raise Disc just a few points on the F75.... the dime is nearly .... or completely undetectable. On days where EMI is present..... but very little; yet, requiring me to increase Disc just a few points to stabilize the F75....... yep, the dime is not detectable. This is ALSO to say that ..... with this 'very little' EMI..... if I chose to NOT increase Disc by a few points..... live with a little EMI chatter because maximum settings are retained; ; ; ; this 12-1/8" deep dime is no longer detectable. ------ Another interesting point; on days where EMI is exceptionally/extremely low, I can pass the F75's coil nearly an inch above the ground...... and detect the dime. (Days with extremely low EMI is not the norm).
3. MOST definately. This test is what separates the F75, T2, F70 w/11" DD coil...... from all others.
4. A paradigm exists here. I could write volumes on this one here also; yet, have very limited time. In a highly trashy area, the faster you sweep the F75's coil, the better the detection of targets (in most cases)..... as far as DETECTOR resolution is concerned. BUT, BUT....... the problem THEN becomes the human brain detection element. The audio duration length is linearly shortened ..... proportionate to the increased coil speed. If you pass the coil over a coin at a fairly normal speed...... you may have, say; a 150mS audio high-tone output from that coin. If you double your coil sweep speed; you will now have only a 75mS audio length duration output. ------Now, if you have a target that.....at best...... only puts out a 60mS audio output into your headphones at a normal sweep speed..... then you whip the coil over the target;..... your brain/ears may not register on the exceptionally short audio presentation. ((( Or you simply write it off as a 'ground chatter' non-target; subsequently resulting in a 'no-dig'...... non-recovery ))). You can move the coil quite slow in trashy areas, , , the detector may lose a slight amount of target resolution.... but you will gain better 'human audio'.
5. Only detector (currently available) that will acquire this particular dime .... within interior of this Fe/non-Fe complex target scenario. Smaller F75 coils will fail to acquire the dime; only the 7-11 DD coil acquires. Part 2 question = not silently masked; rather: masked.

.... Yes, but out of time.

Thomas J. Dankowski

What disc did you use to find the dime 6?

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 SAID:
"The audio duration length is linearly shortened"

It seems like this would be easy to tackle in engineering. If as a detectorist, you knew the site you were hunting and understood a setting that lengthens all tones in a "requested range"... this wouldn't be an issue. You'd just activate a feature that lengthened those tones. ESPECIALLY if you could layer the longer portion of the likely high tone with the subsequent/prior likely low tone - using a stereo output.



Edited 2 time(s). Last edit at 04/10/2009 05:17PM by Shambler.

Yes Lawrenzo, you hit the nail-on-the-head....... again! Set-up config is critical. The 6" dime should be easy for most any detector; however, due to its handicapped status...... several things must occur.

For purposes of 'appreciation'....... let me explain some other things =

Most all other detectors could not even "partially" or "start" to report/detect this dime. Especially concentric coil equipped units. ((( You are starting to see just exactly how critical a elliptical DD coil is ))).
The Explorer (with its concentric DD) audio will remain 'in-the-null'.
The old Soverign XS with the old 8" pie-pan CoinSearch DD coil JUST STARTS to 'grunt' on the dime. Hence; my respect for that old coil.
The T2 will acquire the dime..... but in a ratty/non-positive/non-'lock-on' fashion....... and many folks would not dig the dime, , especially if they are 'cherry-picking'.
The performance of the F70 is nearly in the same fashion as the T2. It will acquire the dime..... but audibly sound 'smeared'.

And now; the F75. The F75 audio is very discernable..... very positive audio ID. The VDI jumps quite a bit..... but the audio is 'positive'. This is with Sens '99', Disc '0', PF or DE, and 4-tone. If I invoke BC mode.... the dime completely disappears. If I select monotone; Disc must be on '5' or '6'. With Disc '5',,,,, the dime is a no-questions positive, hard hitting audio.... but the nails are slightly more than a snap-crackle-pop. If Disc is on '6'.... the audio duration length is quite a bit shorter on the dime...... BUT the nails nearly completely go silent....... giving the dime a much greater discernable audio differentiation...... even though, quite a bit shorter audio presentation. Your ears/brain discern better with this greater differentiable scenario.

Interestingly; The T-square (T2) is a 10" dime capable unit, , , yet it badly struggles with the 6" dime complex target scenario. The extra punch of the F75 is highly prized. ---One particular old home site..... I clearly remember (and head-to-head tested)..... finding dozens more coins on the front lawn and left-side lawn with the F75.... that the T2 missed. Most of the coins were only 7" - 8" deep. The T2 would/could not detect these coins. Head-to-head. The F75 acquired.... but was struggling.


Shambler; I understand exactly what you are saying; however, you are MUCH better off .... being armed with 'realistic' length audio presentation...... vs. ....... artificially lengthened/enhanced audio. While the detector is reporting a artificially lengthened audio report whilst the coil is still covering more/additional ground, it'll THEN miss adjacent targets. And if there are two targets in extreme close proximity........ say; separated by only 1" or 2"..... with the first target being a high-tone aluminum screw-cap....... and the second target being a mid-tone gold coin; ; ; .......... but the unit decides to artificially lengthen the high tone...... and continue to report a standard full-length audio high tone...... whilst the coil continuing its motion...has now passed over the mid-tone gold coin..... which may/may-not give a response. And layered audio via stereo channels in a set of headphones.... could still be confusing..... possibly misleading.
It is better to learn the Soverign coil 'wiggle'...... employed on the F75 platform. Simply slowing down your coil sweep speed.... will lengthen audio duration... in linear fashion, , , no fancy electronics reqd. Contentions with masking culprits, I'll always want realistic audio dialog.

Tom