2F VS monotone in "O" disc............

Hi Tom...........

I finally got the chance to spend a few hours across the street last week...at the "Reservation". (where we have dug 100+ indains.....2 centers... flying eagles...and shield nickles recently. )

Since the site was getting pretty dang silent (as far as DIGGABLE signals went)....I opted for "O" disc....instead of my usual 6.....to put to the test all I have read about the benefits of 0 disc, and the improved separation.
OK....I gotta backpedal here a bit. I've also read (here in fact)...that hunting in 2F with the F75 gives you an effective disc setting somewhere about 15-16.....regardless of how low your Disc setting is. Ok..back to the present!
Well, I hunted in 0 disc....at 2F.....and got quite a number of diggible hits....that would ID pretty close to their actual VDI.....BUT when I went in and changed my disc back to 6.........about 75% or them WERENT diggable signals anymore....proving to me that they werent just targets I'd not walked over before.....but targets that the setting of "0" now allowed me to hear. I dug 5 more fatties....and a number of lower conductors that escaped me before.
I kinda had it in my head BEFORE I verified this...that to get the benifits of 0 disc.....you had to hunt in monotone..........but from what I saw across the street...0 disc seemed to help a LOT....even in 2F.....DESPITE having an effective disc of around 16 when in 2F.
While I'm sure it will be even more effective in monotone ....hunting in 2F is far easier.... (and seems to have similar benefits)as you dont have to keep your eyes glued to the screen. I just dug everything that didnt report audibly as iron. There is a LOT of Iron at this site....mostly in the form of little rusty nails from some sort of small structures that used to be there. hunting in monotone isnt really an option.........as it would likely give me a BIG headache!!!
Any thoughts??? Suggestions?? Streak!

Your results are exacting. Now..... if you can raise the Sens to '99',,,,,,,,,, try that. THEN..... IF the unit will let you; go into the 'JE' mode and hunt again. Try different approach angles. Lightly scrub the coil. Audio Disc is on '15' when you are in all tone options..... unless you are in monotone.

Tom are you saying unless your in 1 tone monotone the machine will automatically
give a disc of 15, even when its set on disc 0 or say 4 disc in say 2F or am I missing the point...I hunt in all tones and in monotone usually conditions dictate the setting options..
Tom when you speak about EMI, Have you actually took the F75 apart and is it sheilded or does it matter, I am asking where is the EMI getting into the machine, coil, or is it a Bleed issue..I realize EMI is in the air..But what can a manufactuer do to help prevent it and still keep a powerful machine..thanks james

James,

I know that I answered this in several threads and in several posts below......... but let me see if I can say it a little bit differently.

Say; you have a silver dime and a nail at a handful of inches deep. The two targets are close enough to each other.... and laying in such a fashion so as to give you a VDI ID of...say; '13'. Let's say your F-75 Discrimination is on a setting of '6'.

1. If you are in '1' tone (monotone).... the F-75 will give you a good audio response to the target. (((You will most probably recover the target))).

2. Say the F-75 is in 2-tone (or 3, 3H, 4, 4H tone options etc.....). Now......... the F-75 will respond with a audio response that most detectorists will NOT dig/recover. The F-75 will report a 'iron' tone (the lowest sounding audio tone). The non-ferrous silver target will most likely NOT be recovered....... even though most all nails will discriminate out at a Disc setting of '6'.

THIS IS BECAUSE; When 2-tone (or 3, 3H, 4, 4H etc.....) is selected = ANY target that results in a VDI ID reading of '15' or below....will report as a 'iron' low-tone. Most folks will NOT recover iron tones.
I have explained this many times.... in many posts below; Sooooooooooo ,,, if my explanation is not clear enough here.... I may have done a better job in posts below.


NOW.......... that being said. (((( If you are in a nail infested area, and you do not audibly fatigue easily = = = )))) IF, IF, IF, you can handle a lot of noise.... and the detector can handle (not EMI plagued) a Disc setting of '0' and a Sens setting of '99'....then hunt in 2, 3, 4 tones (your choice),,, hunting for the "deepies". YES.....the detector will mask some targets in this audio selection config (ie 2, 3, 4 tones are selected) because any (heavily masked) target that VDI ID's as a '15' or below will present a 'iron' audio response (as so stated in example above),,,,, BUT, BUT, BUT the trade-off is; the F-75 will go deeper just by virtue of the Disc setting being '4' or below (especially '0').

Soooooooo, I am saying (by this set-up config) = MORE MASKING, BUT GREATER DEPTH. Hmmmmmmmm... trade-off. Which one does better? Disc '6' & monotone???? or Disc '0' and multi-tone???? The answer is: They BOTH do!!!!!!!!!
I am saying; HUNT the area in Disc '6' & monotone...... and do all the 'unmasking' that you can. THEN hunt in Disc '0' and a tone-option of your choice.... going for all the deepies.
NO...... you can not have both at the same time.... (((unless you're really good!!!))).

* 99% of EMI enters thru the coil. ((( Control box is not shielded....but is usually not the 'cause' ))) Dave J. & John G. are well-aware of the EMI issues, and understand the magnitude, the level of difficulties to mitigate this inherent single freq .... high powered unit's issue. And in the F-75's design..... there is minimum component-to-component 'cross-talk'.

* You have NO idea how difficult it is to design a 'functioning' detector. There are THOUSANDS of issues to deal with.... most interact/play AGAINST each other. There are MANY things we do not think of..... MANY things we are COMPLETELY unaware of.... that are 'exposed' in the design phase; MANY things rear it's ugly head! How do you know what you are missing...... if you don't know it even exists!!! Why would a rusty nail ID as a '4' at just a few inches..... yet.... STILL ID as a '4' at MUCH GREATER depths!!! And how DO you reduce internal component cross-talk!!! Which specific components are 'show-stoppers'!!! And just exactly what SPECIFIC.... and how MUCH shield paint must be applied to the coil !!! What are the thermal characteristiscs of each electronic component.... and how solid/stable/repeatable/reliable is each component as they change throughout operating temp changes!!! What material should be used for the face-plate film so as to mitigate UV breakdown!!! Pistol-grip foam density..... coil wire gauge so as to provide proper impedence; yet NOT change impedence AND NOT BREAK whilst donning/doffing coil thousands of times. THE LIST IS MILES LONG!
It's not easy guys..... it's not easy! The CZ took over 4 years in design... and Dave Johnson was NOT ready for release/product roll-out.... but was hand-cuffed by corporate deadlines & finances.

I could only... AND CAN NEVER commend enough!!!!.... folks like Dave Johnson, John Gardenier, ..........Bruce Candy, George Payne, Kenny White, Charlie Garrett, Eric Foster, Jack Gifford and other DE's of the detectors we live by. We take it for granted... and DO NOT know it!

Tom

Thank you Tom..Yes It all makes sense..sometimes I need a Bat across the Head for it to sink in...Now I understand ..Thank you for your time and revisit on the monotone subject..
Tom great explanation on the Build of a machine, and I'm sure the FCC has limitations for power output...Have you noticed how Busy the F75 gets at a sense of 95 or higher with the coil on or off especially with dics 5 or lower in De pf ..just wanted a professional opinion on the subject..Thanks for the Info..Was trying to determin the root cause of the jitters when amped up..I could only imagine the tought process that was used making such a powerful and potent machine like the F75...Just imagine the performance and depth if we could run the F75 in JE 0 Disc and 99 sense more often..I'm sure I would start filling my age more with all the possible digging up New Items..james

Would like to see the F-75 taken yet.... one developmental step further..... primarily in the 'depth' department.

Like you so eloquently said.......the process of developing a functional..USEABLE and dependable Detector is no easy task......and the powers that be are to be commended for the caliber of the stuff thats out there...DESPITE the hurdles they must face every day in the design process.
The purpose of my origonal post was to simply show that there are benefits to using "O" disc in 2f.....AS WELL as monotone.
Running the F75 in a sequential mode configuration in any given site may very well allow a site to be productive long after its Deemed "hunted out".

First few visits, hunt in your usual most productive configuration. Maybe DE, 2F, moderate gain.
When the targets start thinning.......... go to "O" disc.... 2f.....a bit more gain (as much as the site will allow)

Final visits............ Monotone............. "O" disc.......and gain as high as you are able to tolerate.

Thats kind of how I have been treating my sites since getting the F75...as opposed to writing the site off with previous machines after a few visits...due to performance limitations. Its nice to know that you have "options " with the F75 that allow you to push the envelope....and keep a site productive!!!
Streak!

You have to wonder after the F75 was out on the open market and Fisher started to come out with its new line of detectors what Dave Johnson is working on next. I am sure he now has time to take the F75 to the next level. I wonder what some of the compaines do after they finish a line of detectors? Whites has not come out with something new and different for years now.

Fiher seems to be the only company that offered a detector that really was different from what is out there. So is the rule of thumb that you take five years or so and take your time designing a new machine. It must take a long time to design a new detector that works as Tom said in this post.

Whites has a new machine coming out that seems that it won't be for everyone but is going to be deeper then any detector out there. For me depth would be cool at some of the sights that we found silver and gold at. Most of those places are turf sights. But again if you are at a school or park digging 13 inches or more and trying to not look like you are making a hole to plant a tree in it is going to be hard to not draw a crowd.

I have never gone relic hunting where I needed more depth then the F75 has...but as you know if you scrape off a few inches of dirt you start finding more targets you couldn't find with the topsoil untouched.

It is always great to get a few inches of dirt off to make targets come alive.
As Tom said on the F75 and mono tone with a disc of 6 and unmasking targets that read as iron you can always get a low tone and go from three tones to one and recheck the target? I know that is a lot of work but one way of doing things a bit differently.

I did hunt yesterday with 0 disc on the f75 and it worked really well for me I guess I am getting use to all the chatter but I found some really nice targets.

LowBoy

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1. I have YET to be able to hunt a nail infested site with Disc '0' and Monotone. ((( This means EVERYTHING will give a tone...... and you must keep your eyes glued to the VDI ))). I can hunt a nail infested site with Disc '0' but must use a multitone option.... usually 4-tone.

2. Just by virtue of being able to run the F-75 with completely different set-up config's for the SAME site..... each time you hunt this same site over again.......,,,,,,,, is like having several DIFFERENT detectors-in-one; especially with the F-75. And ESPECIALLY when you are on max Sens '99' in monotone.... and you have your Disc set on '4' or '5' or '6'........ just BARELY enough discrimination to disc-out most nails (not quite all).

3. Dave Johnson is not sleeping!!! He loves challenges.

4. IRT new detector releases; Fisher has released the most 'new design' detectors ... in the shortest amount of time,,,,....... over the past couple of years.

5. Depth is MUCH more critical then most realize. When you are detecting a 1840's site..... and you are finding 1940's coins at 6" - 11",,,,,,....... you should automatically wonder where the 1840's targets are at. Depth is critical. YOU DON'T KNOW.....WHAT YOU DON'T KNOW! Remember; paper money was NOT respected very much in the 1800's....... through the Civil War (ie Confederate States of America paper money, private bank notes, individual State bank notes, etc...) through the 1929 depression..... and on into WWII. While paper had multiple sessions of 'uselessness'..... silver & gold was ALWAYS respected/desired.

6. If White's comes out with a deeper-than-all-others detector...... I'll own one; .... even if it has some small problems.


Tom