Max depth with F70

I have found many responses from people on this and other forums about not being able to get very deep signals with there F70 detectors. Unless you are detecting high mineral soil like most other brand detectors your depth readings will suffer.However there are a multitude of ways to get good to excellent depth readings. If you be sure and set disc to a setting that will quiet your detector some if not entirely then reduce sensitivity till the the detector quiets down doing these settings after first adjusting your HZ settings to the quietest setting and then ground balancing the detector. The sensitivity setting only reduces the return signal not the sending signal. In fact I have found in many instances a lower sensitivity setting gives you a better received signal and steadier VDI reading. You can over power your detector to a point where it will affect your depth and VDI readings. This seems to work for me and I have gotten readings to depths of 12 inches on many occasions. I have found dimes at 9 inches following this method of setting my detector. Remember that disc setting of 4 or lower and 20 or higher gives the detector a power boost. I have found little loss of depth using discrimination settings but will lose some targets to masking when not using all metal settings. Even using some discrimination settings I still get better separation of targets then many other detectors. Just a little info that may help you. I have found that I can get as good or better depth readings with my F70 as I can with my Explorer SE with the pro coil. Also I can beat the Explorer 5 inch coil by a bunch with my Fisher 5 inch DD coil.
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I am always looking for ways to improve my F70's performance. You have intrigued me with your ideas in this post. I think we both have similiar soil(Illinois/Indiana)so we should be getting similiar performance. When you talk about lowering your sensitivity, how low are you talking? Also how high are you setting the Disc and the Threshold? Thanks for posting on this topic!


Oh yeah.....one more question. Have you experimented with the SL setting? I have just recently starting trying it in tall grass situations thinking it might be similiar to the Boost on the F75 but my two sites I have worked like that didn't produce for me or the guys using Minelabs so the jury is still out.

Usually have my Disc settings at 4 up to 6 and 19 up to 25 depending on the amount of noise. I have never been able to use SL mode effectively because of to much trash where I hunt. I have lowered my sensitivity as low as 60. Only when I cannot get the EMI to quiet down using this method will I lower the threshold setting off 9 to minus 2 or three. But by doing this with the threshold setting I will raise the sensitivity to 95 0r 99.because messing with the threshold can lower the depth by quite a bit. Where noise is non existing I run 0 or 1 on my disc and 80 on my sensitivity. I use DE setting all the time and 4 tone setting Sometimes I use 1 or 2F when relic hunting.

FWIW, limegold...when I had my F70, I messed around in my test garden with sL -- as it is indeed a "precursor" to the "boost process" on the F75 SE/LTD (I have been told by folks at Fisher -- Dave J., I'm thinking...) I did for sure observe that I could raise my coil and run a few inch air gap and STILL hit a coin that was "fringe depth" in DE mode.

Steve

Using an early F70 tried many ways and settings but when I got superior depth along with it came EMI..

Seems like thru trial and error fellows have found out to setup their units and F series have become the favorites of many....again whatever works in your neck of the woods as they sure are light units with good ID and ergonomics.

Coinseeker,

I have never been able to get a good handle on the threshold setting. I believe default is -3. In extreme trash and high emi lowering to -6 let me increase the sens. How much depth am I losing turning the threshold down?

I try not to use my Threshold setting any more then I have to keeping it at 9 if possible. Air test your detector on minus 3 and at a setting of 9 when you have eliminated EMI by adjusting your HZ to lowest possible AMI sounds. Then Set your Disc upward and your sensitivity lower down to a max of 60 in air testing you don't need to ground balance. Measure your depth with a dime and a ruler to measure it. Then turn your threshold from 9 to minus 3 and see hoe much depth you will lose. Then you will have an idea of how much depth your threshold will cancel out on your machine.

I just air tested my F70 with the settings of 80 sensitivity, threshold 9, disc 6, sounds 4 and DE setting. I got 13 inches depth on my 11 inch DD coil with a dime. I then set the Threshold to -3 and could only get 9 inches of depth. At a threshold setting of -6 I could only get a depth of 6 inches on a dime. This is why I don't mess with the threshold setting below 9 unless I can't get rid of the EMI by adjusting the HZ,Disc and sensitivity settings first.

Coinseeker,

Thanks for the information and extra effort on the air test.