F-75 LTD ...................:fisher:

[Elton]

Exact settings I used may not [size=large]work in your dirt[/size]..So be prepared to play around a little to get the results you want..

Maybe less, or more sensitivity, maybe a little less discrimination will be required to get optimum depth etc.. EMI may be a factor for some .

 

[Bassinsmitty]

So you are saying run up the disc over 60 and notch in what ever you want. If so would you loose depth?

 

[Elton]

Not much depth loss with the F75 ....Unlike other detectors the F75 is touted out to have an increase in depth ..High gain in discrimination above 30 ...

I was amazed at the depth in my dirt...with 65 discrimination..

 

[ezra]

Not trying to rain on anybodies parade BUT if you run high discrimination at 65 you will not get indian head pennies. I just air tested about 10 indian head pennies . One indian registered at 44 the other indian pennies registered from 55 to 59 on the F75 LTD with the 11 coil Just thought I would share this Ezra.

 

[Elton]

Silver, wheats, large cents, that sorta thing Hardly no rings, or Indians ...

 

[Elton]

I was told the f75 discrimination may not work on all deep targets .... some of the old pull tabs from early 60's might sneak through due to some leaching around them.They had different metal properties than todays tabs have he mentioned.. With leaching the 75 sees a larger target sometimes
He further stated the F75 up Id's and that was intentional in the operation...????

 

[WV62]

Here is some testing results from a std F75, notice the 2 1/2" jump in depth when I went to disc 65.

Ron in WV

 

[REVIER]

Just one more thing to try and experiment with, and another very good reason why these high end Fisher units just seem to amaze many with so many different settings that are possible.

 

[Bassinsmitty]

I have been hunting an old farm 1830's. I need to try these settings. Found some silver but stalled out. Nothing but wheat pennies and clad of late. Lots of caps, tabs and iron. I have been digging a lot of junk. I'll let t you know how I make out.

 

[Elton]

Yes please do ...........let us know..

 

[goldman55]

Good Stuff to know Good Chart. Well sent my T2se in Monday. Hope it comes back good Had a Gold Bug pro when they first came out, had to send in because of coil they just sent me a new one. Cant wait to get it back .

Bill

 

[Elton]

when you can hit 9 and 10 inch dimes..........that is getting to an awesome depth area.........

if it ever stops raining I am going to try more experiments with the 10" concentric in some high junk areas..
I also notice your chart reflects my actual in ground experience on dimes, and lone quarter at 11" I hit..

 

[marcomo]

Elton, thank you my friend for this excellent thread and the new knowledge (to me, anyway) that you are sharing.

I had always assumed that since the F75 was built for the DD platform, a concentric coil would not be the way to go. The few reports before now that I had read on the concentric had backed up that impression. My guess is a lot of F75 (and T2) users are going to rethink their strategy based on your findings.

I do know that when EMI raises its ugly head with the F75 there are four ways to effectively combat it. I say effectively because there are certain things you can do, like change the frequency or re-ground balance, that are worth trying but seldom help much.

Switching machines is an option, but what's the point of having a high end detector if you have to do that? Obviously you can lower the sensitivity. Another way is to switch coils...the 5" coil can almost always be used at close to max sens in my area with very little or no chatter. The last way is to raise discrimination. With my F75, when the discrimination is maxed, or at least up into the 50's, chatter is usually eliminated or greatly reduced. The advantage to that is you mitigate the EMI without losing depth. The disadvantage is you lose any lower conductivity targets. The additional masking you get when you add discrimination means the less trashy the area the better this technique works.

 

[goldman55]

You know the F5 when looking at video's its deep and accurate on the vdi with the concentric coil on it. I know its the F5 not the F75 but still Fisher Product same as T2SE you can kinda get a feel for what they are doing as far as the units. Anyway seen the F5 hit dime at 8" in a video with the concentric coil on it. I think the F75SE is a F5--F70--T2SE all in one just depends on how you have the F75SE setup. More you read and see sure seems that way. Best machine I have ever had.

Bill

 

[Elton]

It would of course seem it will work better in non trashy areas.. However I want to try a trash laden area..I have a gut feeling I will be able to find masked or at least partially masked coins with the 10" concentric coil.

The upped disc with the maxed depth using the 10" just may find deeper coins the 11"DD masked out... due to the larger footprint end to end...on the 11"DD. I am hoping the 10" concentric with it's smaller conical footprint at depth will hit a few of those coins.. .. It may take a little more time to hunt the whole area..but the rewards may be some prior missed silver coins..

 

[WV62]

Trash areas are the last great frontier.

I have started searching for a good deal on a 10" concentric coil.

Ron in WV

 

[Charles (Sabre)(Tx)]

The F70 10" elliptical concentric has been no secret to me with the F75...I prefer concentric over DD. The 3X6" works wonders for me over the 5" DD also. But...and I know you are going to say that they don't make it...an 8" concentric outdoes all my other coils for the F75 LTD. I think the one I use on my F75 is part of the "Greek series" usually found on some of the Tek units. It works and it fits. JMHO.

Charles

 

[Whimpster]

Sooooo....your saying the 8"concentric would work....off my Omega 8000 and work on my F75 LTD!!
I thought the 8" concentric F70 Coil was the only coil that would on the F75....
guess I'll have to try it....hummmmm.

The F70 10" elliptical concentric has been no secret to me with the F75...I prefer concentric over DD. The 3X6" works wonders for me over the 5" DD also. But...and I know you are going to say that they don't make it...an 8" concentric outdoes all my other coils for the F75 LTD. I think the one I use on my F75 is part of the "Greek series" usually found on some of the Tek units. It works and it fits. JMHO.

Charles

 

[D&P-OR]

All kinds of good info coming to light regarding coils on the F-75!--------Charles---when you say the Greek series 8" conc. outdoes your other coils---in what way(s) are you referring to?---depth, separation, etc.?-----My main question to you---does that 8" conc. calm the F-75 down as far as EMI (and stability) is concerned?-------Very good info you have here, thanks for sharing it with us.

The F70 10" elliptical concentric has been no secret to me with the F75...I prefer concentric over DD. The 3X6" works wonders for me over the 5" DD also. But...and I know you are going to say that they don't make it...an 8" concentric outdoes all my other coils for the F75 LTD. I think the one I use on my F75 is part of the "Greek series" usually found on some of the Tek units. It works and it fits. JMHO.

Charles

 

[Elton]

Per Fisher the greek series 7.8 khz [size=x-large]IS NOT[/size] compatible with the [size=x-large]Fisher F75 or the F70[/size] 13khz..Can you offer more information on your 8" coil post
before everyone orders one, and it may not work..or may cause issues with their F70/75 detectors... The machine frequencies are VERY DIFFERENT

Thanks my friend I and I'm sure others would appreciate this information..

[size=x-large]I like to make certain the info is accurate on the Fisher F series forum[/size]...


Elton Fisher F series forum moderator