F70 Settings

[fjs440]

I just upgraded from the F2 to the F70 with an 11’DD and I am playing with it in the garage, because of steady, cold rain. (NE Ohio)

I feel like if I can understand the F70, I am going to love it. The F70 seems to be an overpowered psychotic monster wanting to get loose and it is my job to keep it under control. My F2 does a great job on reasonable depths, but I need more depth for the local black-sand beaches. They have been overworked, but they are the only things I am physically able to do standing up.

I have noticed that going to zero discrimination and slow speed cranks this thing up. Anything else quiets it down and gives it less depth. That can be useful for trashy areas, so that is good. So I start with slow speed and zero discrimination. (This reminds me of flooring a Corvette during the ‘60’s when I was young!)

I guess the question is, does Sensitivity or Threshold have more influence than the other on depth? Where should the settings start before I get rid of the noise? What else am I missing? You know more about this than I do. With a machine like this, I doubt there is a simple answer. I am just looking for where to start.

Hope you all find lots of goodies. Happy New Year!
________________________

Fisher F70 w/11” DD
Fisher F2 w/4”, 8” and NEL Hunter Coils
Fisher 1280-X w/8”Coil

 

[REVIER]

0 disc will give you a lot of chatter, even turning it to 1 quiets it down a lot.
I never hunt on 0 and don't worry much about losing depth with the sense set low, either.
Supposedly this thing does not lose much depth at all as you turn the disc up unlike other brands and models.
I have run it from 1-65 and don't notice much difference.
Anything under 5 or over 20 gives a slight boost in sensitivity but also chatter, sometimes.
SL will get deeper than DE, but it will open you up to more chatter, also.
You might not realize how deep this thing will actually get in decent soil on lower settings...don't assume you know until you play with it more and see for yourself.
I have experimented a ton and some settings are deeper than others but the kind of soil has a lot to do with depth, EMI might too, everywhere is slightly different, don't assume you know about depth till you spend more time digging in your soil.
I am not saying you will hit the same deep areas on all settings but there are technical things you don't yet know about.
The sense range is not what you might think it is.
Startup 60 is not 2/3 power, 50 is not 50%, 33 is not one third and so on so turning it down some to hunt quieter, if that is how you want to do it, you might get deeper then you might believe.
There is a relationship between the sense and thresh settings, start at factory levels and adjust higher from there.
It has been described as sense is power, thresh is the raw signal before processing, or, the thresh setting is like opening a door.
High positive you hear everything big and small, as you turn it down the door closes and the more it does the more the smaller targets cut out.
I can still hit coin targets pretty deep on -4 so far and it is pretty quiet.
I learned to hunt with pretty high settings, just got used to it, chatter doesn't bother me and when the coil moves over a target it calms down and tells you, anyway.
If you can believe it I found that all metal, sense and thresh maxed out and SL speed gets me not only the deepest but it does give me some of the best, clearest and best ID's on signals and is actually less bouncy and battery than using disc.
Still noisy for sure, but less noisy than you might think compared to using disc and my go to settings in heavy iron situations and on program 2 as a check for most deep signals.
It took hours to use and understand what I was seeing and hearing using these "blast through" settings...well worth the time spent to me.

Spend time on factory or lower settings and DE.
Get used to it then start turning it up.
You have time, the thing will find almost anything both shallow and deep as you learn.

 

[still looking 52]

Most high end machines like yours has a factory default setting and for beginners this is a good place to start. After that you can start playing around with the other settings. I'm not what you would call an expert but a couple of basic things is the higher the sensitivity the greater the depth and a lot of us run that as high as possible until the rigg starts to chatter and then just back down from there. Disc settings doesn't seem to affect depth that much and threshold settings is not a big factor on depth either. Maybe Revier can give you some more help if he reads your post.

 

[MarkCZ]

I'll throw in my 2 cents on the threshold, or another understanding of it.

Detectors of OLD, the 1980's and early 90's the threshold was a manual adjustment that you dialed up an audible sound (tone) just to the point that you could hear it and it was that level that was your "Operation Tone".

Well, moving through time and into the next realm of electronics the threshold become a bit more confusing for us old timers because many of the newer units are commonly termed "Silent Search" detectors, but the term "Threshold" is still used, now if that isn't a head scratcher

Old school threshold was usually a nice low constant tone.

New school threshold, isn't that ALL!
The detectors are silent search below the threshold setting of "0" and that's not to say that your not going to hear beeps and chirps, but what your not going to hear is what is called "Detector Noise" this is the noise of the electronic circuits of the detector. With the newer units if you set a threshold higher than "0" you leave the realm of silent search and inter into the range of "Detector Noise" but its not a nice tone, its just electronic noise, clicks, ticks, and static that confuses the operator. Running a newer detector into the "noise range" is best left for veteran users of these types of detectors, other wise we get lost between faint targets and the noise.

Now, that covers what is above a "0" threshold, but what about below "0" or minus "0" (-1__-2___or -6 and so on).
I like to use the term "Trigger" or "Gate" when talking about modern threshold, and its still in the audio department. Think of it like this, the audio amp sends a report (an alarm) to the operator when something comes through the detection circuit, well the threshold has an adjustable trigger (gate) for the audio amp to either "Except" a response and pass it on to the operator or, "Reject" it and ignore it.

At "0" the audio amp is set to its most 'Sensitive' level and still remain silent search. Well, at "0" the audio amp is very jumpy much like a hair trigger on a firearm, any little thing will trigger an audio report, the slightest tick, any form of EMI, and you'll hear it. (I'm thinking stability, or lack of it)
Now, its good that we have control over the threshold and we can dial it down, the higher the minus number of the threshold setting the stiffer the trigger is for the audio amp, a minus -8 is going to take more signal input for the audio amp to except and send the report to the operator than a -3 setting.

Okay, now lets add in the "Sensitivity" it sounds much like the threshold and it is, except its not adjusting the except or reject range of the audio amp (actually pre-amp). Sensitivity is on the other side of the electronics, that is the detection circuit. In basic terms as you crank the sensitivity up the detection circuits become more sensitive to smaller and or fainter targets. Now that's just basic! because with a lot of the newer upper end models the manufactures has incorporated other aspects into the sensitivity control.

There isn't any reason to run your sensitivity @ max and your threshold @ -9 (minus 9) or vise-versa a "0" threshold and a sensitivity @ 2 you would be countering the effects one control with the other.
Lets take clad stabbing, surface hunting a fairground for fresh drop coins,
You don't need any depth,
You don't need any clicks, ticks, or other faint audio responses.
So, you could use a sensitivity of lets say 20 and a threshold of -6 or maybe even -7 (with smaller coils you may want to raise these number a bit) notice that both the sensitivity and the threshold went down! these settings could be referred to as Mild settings, but it should be very stable and perfect for the job at hand, "clad Stabbing"

Now, lets say someone you know lost something smaller than a US dime (or other small coin), its a fresh drop, but its smaller than average coins, so you may need to turn up the sensitivity a tad for the detection circuit to pick it up, but the threshold may be fine because its small and its close to the coil it would still gate the audio pre-amp. (still mild setting)

Now, lets go hunt some deeper older coins!
This is going to take some hotter settings, which normally will be as HOT as you can run the detector which is more often than not limited by stability!!
You know you don't want to miss a faint signal, so the threshold is going to need to be set closer to "0" and the sensitivity is going to need to be turned up. On my F70 and my area I've found that with the 11" DD coil my MAX (HOT) settings are,
Sensitivity @ 70
Threshold @ -2
if I get a lot of little ticks and pops I will most likely drop the threshold down a number or two (-3 or -4) to stiffen the trigger for the audio pre-amp. Now if I'm getting stronger false type signals I would probably lower the sensitivity down to maybe 50 or 60 and bring the threshold back up to the -2.
The point is that I never make a wide swing between these two controls, I may move one a little, if the detector still isn't stable then I will bring the other control down a bit.

Hope this helps!

HH
Mark

 

[big-ears]

Markcz,

I think that is the clearest, most concise, interpretation of the F70 controls I have ever heard! Thank you................

 

[fjs440]

You guys are impressive. That information is what I am looking for.

 

[MarkCZ]

"big-ears" & "fjs440" you're most welcome!

I'll be surprised if my post doesn't stir up a debate LoL there is WAY more technical terms that are used, but for us normal users its the tech stuff that zooms right over our heads (well my head anyway)

HAPPY NEW Everybody!

Mark

 

[still looking 52]

Man it's nice to have a little brother like Cz5. That's an excellent explanation on those settings. I'm thinking you nailed that one little brother. That's going to help a lot of people with their detectors to this coming year. THAT'S OFF THE CHARTS!

 

[MarkCZ]

"big-ears" & "fjs440" you're most welcome!

I'll be surprised if my post doesn't stir up a debate LoL there is WAY more technical terms that are used, but for us normal users its the tech stuff that zooms right over our heads (well my head anyway)

Fixing a type-O, I find them even in my little post.

HAPPY NEW YEAR Everybody!


Mark

 

[WV62]

First things first, learn how to do the factory reset, I think it is on page 9 of your manual. This will clear all the settings that may cause your detector to act up. I have seen a lot of post where guys are about ready to send there machines back for repairs, and somebody will tell them to do a factory reset and their detector is fixed.

Looks like the above post got most of the middle.

Last things last, I would suggest not messing with notches until you got all the other settings figured out. When you get around to playing with notches I would strongly suggest a factory reset after you are done. Setting notches seems to be where a lot of new users set something and don't get it cleared out. I have been using a F75 since 2007 and just about every hunt I start with a factory reset, which makes me set the machine up for the days hunt.

Nothing said here is a must do, just a heads up.

Ron WV

 

[mvd]

What an awesome description on the threshold. Thanks so much!! It does help to understand especially for the guys who have spent most of their time with older units.

 

[drittless]

Thank-you MarkCZ and others. Although I had to read the post several times, I think I'll actually remember those functions now. So when you ground balance, are you sort of setting a quiet baseline to begin from? Will changing frequency help with that? Frequency doesn't get discussed often, maybe it's not a big deal? I'm a slow learner I guess.

 

[MarkCZ]

Frequency!

This is more of a 'Shift' and not a channel change.
It has a couple of primary uses,
If your hunting in close proximity to another hunter using a detector on the same frequency you have the option of a 'Frequency Shift' to reduce detector "Cross Talk". (such as club hunts)
It can also help in certain types of EMI to increase stability by shifting the frequency in one direction or another.

"Ground Balance"
It sets the internal circuitry to ignore minerals in the soil, in other words, to better deal with the effects of ground mineralization.

Mark

 

[drittless]

Does frozen ground effect ground balance? I would assume you guys get tired of addressing these questions. Have any of you considered offering real time field seminars for small groups? I'd love to spend a few days actually using my F 70 under different conditions to learn this machine. Would be even better during my Minnesota winter if it someplace above freezing. Then I think about how much fun I have just swinging around sporting fields with my Delta and wonder why I have the need for better technology at all. I leave my cell phone in the car................

 

[MarkCZ]

I do find that certain conditions (changes in the environment) will effect ground balance even at the same location,
Long hot dog days of summer is the worse, I'll start out in the early morning with one ground balance setting (lower) and then by noon I'll have to re-balance. Over the years I've concluded that this is due to much higher amounts of "Solar Radiation" charging both the atmosphere and ground minerals.
The reverse of that is,
Early morning, (or at night)
Cooler days and more moist (damp) soil will tend to lower the ground balance numbers.

Mark

 

[MarkCZ]

Does frozen ground effect ground balance?[/quote\

I've never actually detected "Frozen" soil so, I'll let somebody else answer that!
But, I'm pretty certain that "Frozen" soil would have its greatest effect on 'DIGGING'

Seriously, I do know that certain batteries tend to fail, or discharge WAY more rapidly in freezing temperatures then others.

Mark

 

[MarkCZ]

Does frozen ground effect ground balance?

I've never actually detected "Frozen" soil so, I'll let somebody else answer that!
But, I'm pretty certain that "Frozen" soil would have its greatest effect on 'DIGGING'

Seriously, I do know that certain batteries tend to fail, or discharge WAY more rapidly in freezing temperatures then others.

Well, this somewhat fixes my earlier post if I get the tags right this time.

Mark

 

[fjs440]

I have reread the answers on this post and I am very happy with what you said. I am loving these posts and I think they were the most complete I have ever seen. It is hard to replace your experience.

During the few “nice” days in NE Ohio this winter, I have worked a few yards to tried to get “used” to the F70. (I am coming from a F2.) I did what was suggested and it was working.

I went to a new beach, for me, and the black sand we have on Lake Erie is incredible strong. Getting away from the “noise” was challenging. I will work it out.

I write too much. I just wanted to say thank you for helping me adjust to a new machine. I hope I learn enough to love it like my little F2.

 

[REVIER]

I have reread the answers on this post and I am very happy with what you said. I am loving these posts and I think they were the most complete I have ever seen. It is hard to replace your experience.

During the few “nice” days in NE Ohio this winter, I have worked a few yards to tried to get “used” to the F70. (I am coming from a F2.) I did what was suggested and it was working.

I went to a new beach, for me, and the black sand we have on Lake Erie is incredible strong. Getting away from the “noise” was challenging. I will work it out.

I write too much. I just wanted to say thank you for helping me adjust to a new machine. I hope I learn enough to love it like my little F2.

I went from the F2 to the F70 also, plus I have hundreds of hours using Tesoros so I listen closely to the audio part of this thing is and it has been important especially on a few weird target situations.
My first detector was a horrible unit that had problems, couldn't handle my hot soil and falsed on almost every swing so I had months of training listening to noise and learning to pick out the real targets in all that mess.
A frustrating cloud of confusion but the silver lining was I got used to noise and hyper sensitive to audio clues.
Loved the F2, learned the language and got a pretty deep understanding of the behavior and boy that thing produced for me and paid for itself more than 10X's over in 3 seasons.
The F70 has a lot of the same language but there is so much more, the million combinations possible by adjusting the settings just adds to the enjoyment.
For the first 10 months I was really anal about examining and experimenting with almost every signal, changing settings up down and all around to see what effect they would have because that's how I learn best.
My typical volume of finds suffered because I dug way less than usual but I still found some jaw dropping targets along the way and when I finally settled down with a few favorite settings and hunted my finds totals grew exponentially.
Now I am into this thing a little over two years now, still experimenting some, still learning new things and for as much as I know , as much as I have found and accomplished I really believe I have barely scratched the surface of its abilities.
I can make it ultra quiet or any and everything up to super noisy and it has done the job and shocks me often.
I have found that there is no wrong way to use this thing...there are as many different setting combinations that work and work well as there are different soils and conditions and different hunters that use them.
I have been more successful than I have ever dreamed I could be in conditions that range from ultra mild and great to extreme iron infested to super trashy to heavy mineralization...it has never let me down and my jaw aches from dropping so much.
From low sense to low disc, high disc and higher sense, different threshold numbers, all the tone settings to factory to my maxed out all metal blast through settings, look at how many use these here, what they find and how they differ in their favorite settings.
We all seem to love these things once we get used to them, and we all seem to be able to find the good stuff doing it in so many different ways.
Boredom is a big thing with me, I don't think I am in any danger of getting bored with thing for a long time if ever.
My bucket list items are being checked off one by one as we speak.
Man I love this thing!

 

[dfmike]

Since there seems to be a lot of experienced F70 users here, I have a question to ask: I've never used any other machines than the 7.8 Khz machines that Fisher/Tek makes. Is the F70 easier to use than either the F75 or T2 (the regular versions, without boost protocols) ? Or in other words, apart from cost concerns, would there be any other reason to choose an F70 over an F75 for example ? I don't really want to start a debate over which is better depth wise or whatever. I just want to know why some people would choose an F70 over other detectors of same frequency. Thanks.