F70 separation test.:stars:

[BarnacleBill]

I've read many times about how fast the processor in the F70/75/T2 are in ID'ing closely spaced targets. That is that they can un-mask targets that are missed with slower "processed" detectors. Several users report that they can lay out three closely spaced targets and no matter how fast you swing the coil it will report each individual target with a correct ID.

Taking a break from my heavily scheduled Honey Do List I pulled down the F70 to do some testing to satisfy my curiosity.

Equipment:

F70 w/ stock concentric coil.

Settings:

DE mode.
Threshhold Zero
No Notches
GB low 80's.
Sensitivity varied 60 to 70.
Dirt read Zero(0) to One(1) bar.
No EMI noticed.
Battery Meter Full

Location:

Tried several after checking with All Metal to make sure each spot was clean.

Methodology:

Three coins were lined up in a row; Quarter, Nickel, Quarter.

Expected result:

Based on reports from numerous F machine users being able to bring the coins to the point of almost touching and still ID each individual target regardless of coil sweep speed.

Results:

Beginning with the coins closely spaced I found that I received a composite ID with each pass of the coil, this was not the result I expected. So I laid down a ruler and began increasing the spacing incrementally with ever wider gaps. I finally got out to the spacing you see in the photo below which is three inches on center for each coin.

[attachment 139828 ruler.gif]

And this is where the story gets interesting. At first I thought I had been careless in choice of my testing location and moved the targets to check the ground in All Metal again. Ground was clean so I put the targets back. Same result, so I moved to another spot checked in All Metal and re-GB'd and noted Dirt reading. All looked about the same as the previous spot. I varied sweep speeds & height and got the same results. I again moved and repeated the same routine.

Below in the photo is the ID with the Quarter-Nickel-Quarter at three(3) inch on center spacing. Notice the confidence reading is pegged full on.

[attachment 139829 read4.jpg]

Occasionally the ID would be 12 and rarely it would iron wrap into the 90's.

So there you have it......an interesting exercise that has coins laying in a pattern that would not be unusual for a coin spill that would be found in a park or on a beach. I've documented this so that others can replicate my test and cross check my results if they are so inclined. No... "Bert and I come down to the dock about six o'clock in the early morning. Bert went into the boathouse to fetch the pots and the slickers and I went out to the dock to start up the Bluebird."

HH
BarnacleBill

 

[dahut]

from any detector, Bill. Well done little test, one I make with all detectors I get.
As always, there aint no 'magic bullet' folks. My simple solution is that if you get a repeatable good signal, in at least one swing direction, dig it.

I'm old school, I guess, but then, there 'aint no school like old school.

 

[wayne_etc]

Yep, me too.
I've noticed that the 11''DD coil needs even more space between targets to get good responses for all of them. Expected with a large coil.

Have you tried the same test but using a ferrous object next to a nonferrous object, then (with iron disc'ed) see how far apart they have to be to get a signal for the nonferrous object?


w

 

[dahut]

Have you tried the same test but using a ferrous object next to a nonferrous object, then (with iron disc'ed) see how far apart they have to be to get a signal for the nonferrous object?
w

I have done this in the field with an F70, not measured or controlled, however. But what I have learned under these impromptu conditions is that the F70 will signal on good targets in proximity to iron trash. You can expect mixed responses, and it is a good idea to use the DISC to your advantage, by reducing it when in doubt. This will let you know if you are dealing with an iron masking issue.

 

[Hombre]

Howdy Bill

Did you get 3 beeps 2 beeps or 1 long beep? Inquiring minds want to know. Thanks

 

[Furious T]

So, with a 10"x5" concentric coil?, one side of the coil would be hitting the second Quarter as the second side of the coil was leaving the first Quarter, could you expect anything different to the result you got? Sensitivity might also be a bit high for cherry picking coins on the surface. Just my thoughts.

 

[Mr.Bill]

I do believe you will discover the F75 is a bit different than the F70. Your lumping together the F75 & T2 with the F70, assuming that the F75 & T2 are going to perform the same. They don't.

Instead of the F70, you should be using the F75. Even the T2 does a real good job in those test, try it

 

[BarnacleBill]

Hi FT,

I was simply checking the multitude of statements that have been made here such as:


"I tried to over-swing the F75, but it is impossible. The VDI numbers and tones show up so fast that this has to be the fastest processor in a detector at this time."

"I will say that this detector has the fastest target response of any I have used."

"I have used and onwed every top end unit and almost all mid level units and I can say for fact...it is the fastest by far."

"It has the fastest target response of any detector that I am aware of"

"From what I have seen, the F70 is one of the best buys in the detector field today. Too many T-hunters are over-looking this model. It has incredible depth with the small 3x7 coil for the high trash sites, and fastest recovery on the market today."

"Sounds like you have a general idea of how to work advanced technology but need a little more practice so you can learn how to handle the fastest most sensitive detector on the planet."(Directly referring to F70)

Based on the above I was simply checking for my self the accuracy of the statements. Trust but verify.

Sensitivity was varied & so was coil height to prevent any overload/overwhelming of the circuitry.

HH
BarnacleBill

 

[BarnacleBill]

Well that National Sales Feller wrote me up close and personal like.(Directly referring to F70)

"Sounds like you have a general idea of how to work advanced technology but need a little more practice so you can learn how to handle the fastest most sensitive detector on the planet."

He sure does like to throw around those adverbs.

You must like swimming with those Great White's just to tune up for a phone call with that National Sales Feller!

HH
BarnacleBill

 

[Jackpine Savage]

That's only one test!
How's the 705 do on that one? No DD's allowed

I've seen the Dimitar machines do some weird things also (real world) when nickles are involved.

ie: nickle 2-3" from a modern square tab reading as iron. And why would a large mens silver ring read as iron while wading. Hmm?

Here's one if you have the time and inclination. I have hit several pocket spills containing a mix of wheat and zinc pennies and using a slow sweep from different directions been able to seperate and ID most of them correctly with the Edge and Excel stock coils.

For my gratification try a mix of 6 pennies tossed at random in a 12" circle and see what she'll do. 3 tosses with an average correct read on 4 would be good I think.

Humor me R.T.

 

[SteveP(NH)]

A British detector shop called regton has a series of detector tests posted on youtube that includes the F75 as well as many other top of the line detectors. Their test is a little more demanding as they place a nail length wise in the path of the swing and then place a coin after the nail and see how far apart they have to distance the nail from the coin for the machine to beep on both targets. The F75 looks like it beeps on both when they are about 6 inches apart. This one of the best if not the best result from any machine they test (at least last time I looked at lots of their videos). By way of comparison the Minelab Explorer SE had to have its targets placed a foot + apart and he slowed his swing down for the SE which he didn't do for any other machine.

Here is the link if you are interested

http://www.youtube.com/watch?v=JBCYIoj2fmo

 

[Hombre]

Howdy Bill

Did you get 3 beeps 2 beeps or 1 long beep? Inquiring minds want to know. Thanks

Same question.................Please

 

[BarnacleBill]

1 long low beep indicating iron.

HH
BarnacleBill

 

[BarnacleBill]

I've yet to find an induction balanced VLF with concentric that will pass that test when it is set up properly. Not even the fastest, speediest, highest, lowest, lightest, brightest, coolest, super-er-rest F-machine like the F70.

I thought since I was being "schooled" by FT's best I'd provide a little exercise for them to figure out, as I of course am totally lacking in skills and experience. I've known about this effect for some time but decided that it needed to be saved till it could provide a "teachable moment". But you, you old fart know too much, it's hard to get that sinking curve ball by you.

Moral of story, despite what ANY company wants to tell you in their marketing materials, check it out for yourself.

Every minute of every day is a "teachable moment" here on the F forum.

HH
BarnacleBill


Oh yeah & P.S. .......hey Fanboys please explain the cause of a VLF acting this way.

 

[Jackpine Savage]

"experience" told me you were throwing that sinking curve ball at em.

 

[Hombre]

Hey Bill

I don't want to stir up a stink, but I have several VLF's that will pass this test. They will do better in Norfolk Wolf's test also. I will not name drop them here, you could PM me though..........

Respectfully

Hombre

 

[Jackpine Savage]

Oh Fagedaboudit!

 

[jmaryt]

national sales fella!..(J.W?)

(h.h!)
j.t.

 

[jmaryt]

as john wayne was fond of saying!.."life is tough!..it's even tougher if your'e "stupid!"..everybody learns!..one way or a 'tuther!"

(h.h!)
j.t.

 

[Furious T]

Hi BB. I had presumed it was a "testing claims" situation rather than a venting of disappointed expectations. Doesn't hurt to ask, though. I've had some seemingly amazing things happen while detecting, but I dont think any of the detectors or concentric coils I've used will separate objects when they are under the coil's "sphere of influence" at the same time. Of course as targets are deeper, and the concentric coil's signal at that depth is not as broad as it is at the surface, i.e. directly adjacent to the coil, then it is possible to seemingly separate objects that are relatively close together. How close thre objects are, or how amazing the occurrance might be is often lost in the process of retrieval, in my experience. Doesn't mean we dont have oddities occurring fron time to time, and doesn't mean we cant enjoy them, even though things may not be exactly as we imagine them to be. Good to hear your comments on the F70. Thanks for your patience if you've got this far.