Over load

[rob.ream258]

In learning my F75 and reading the posts throughout this forum, I'm wondering if I have a bad coil (stock) or what I'm experiencing is common.

When working curb strips, near fences, or tot lot equipment my machine will pick up the metal and overload around 18inches away. Possibly 24inches since I haven't measured the exact distance, but in my mind it shouldn't be screaming at those distances. Is this normal or should I be able to get closer before I get my ears toasted?

No one I know in my area runs an F75, so I don't have the option to barrow/swap coils in an attempt to diagnose this annoyance. I would love to get closer to the edges of the curbs, but right now I can't get anywhere near the concrete.

Will the NEL Sharpshooter get me closer? A concentric help?

 

[WV62]

Well I never checked to see how close I can get to steel fence post, but I am thinking 3 or 4 inches with the 11" DD stock coil, nothing even close to 18 to 24.

Ron in WV

 

[Fisher F75 Iowa]

Does lowering the sensitivity help?

 

[jim tn]

I don't use the 11" coil for close work that often, but mine will start overloading within a foot, maybe a tad less, away from metal stop sign and light posts. HH jim tn

 

[Dave J.]

Cranking sensitivity to less than 30 will probably help quite a bit. The range 30-99 affects the target responses you hear and see, but not overload threshold.

 

[etechdigger]

I always use the 5 inch stock coil to get closer in those situations it works great and has help find lots of goodies.Try it.

David in TN.

 

[rob.ream258]

Thank you all for the replies.....I think I'm "sold" on the small coil requirement and not a stock coil replacement.

thanks again and HH,
rob

 

[tvr]

Small coil gets you much closer. I like the 6.5 inch elliptical shaped concentric coil for getting close to posts, fences and along the re-enforced concrete sidewalks.

 

[rob.ream258]

Yep - that is exactly where I'm planning to use the coil - not exactly sure which one but there have been plenty of info in the recent posts.

thanks,
rob

 

[Elton]

Small coil gets you much closer. I like the 6.5 inch elliptical shaped concentric coil for getting close to posts, fences and along the re-enforced concrete sidewalks.

Good coil, and it hits far less rusty pop off caps too from the old soft drink bottles, and beer bottles of yesterday. Since it is a concentric coil. The 5" round is a great coil..but being a DD it does hit the old caps..

 

[MarkCZ]

Small coil gets you much closer. I like the 6.5 inch elliptical shaped concentric coil for getting close to posts, fences and along the re-enforced concrete sidewalks.

Good coil, and it hits far less rusty pop off caps too from the old soft drink bottles, and beer bottles of yesterday. Since it is a concentric coil. The 5" round is a great coil..but being a DD it does hit the old caps..

Here is a picture of the 6.5" Elliptical (its a concentric coil also)

Mark

 

[Mike Hillis]

Sounds like you have BP itis.

When hunting around surface iron, get out of BP mode, and drop your sensitiivty way down. You can hunt around large iron with a sensitivity setting of 1, any process besided FA, BP or CL, 2F audio and hunt with the toe of the coil parallel to the offending iron.

I say 2F audio because the large iron will still give a strong signal but you ignore those and listen for the zip of a small signal. Then after you have moved away from the large surface iron you can go back to your high sensitivity and boost processes.

Drive it like a race car. Gear down on the curves and open back up on the straightaways.

Good luck,
HH
Mike

 

[ramer]

Yes, using the 11 inch coil, I can't get within about 1.5 feet of play ground equipment. But I never tried lowering the sensitivity all the way down to 1 as was previously stated. I always used the DE mode at about 50 sensitivity on the play grounds, this was before I had it upgraded. Now I can set the tones to eliminate
iron sounds and maybe get a little closer to large metal objects before it overloads.

 

[Dave J.]

Cranking sensitivity to less than 30 will probably help quite a bit. The range 30-99 affects the target responses you hear and see, but not overload threshold.

Others have also given good advice: when you're searching for relatively shallow stuff where there's interfering targets, BP is not the mode to use. BP is for less difficult search conditions where you can swing wide and are looking for deep targets.

 

[rob.ream258]

An update to this situation:

In reading and working through my issues and testing the suggestions, I purchased a NEL Sharpshooter just try to help figure things out.

Here is how the coil performed:
I can hug chain-link fences at about 1" away.
- regardless of mode
- regardless of hot it's running
- no need to crank it down
- it only over-loads when I bump the links
I can get about 6" away from big metal
- the stuff that would over load the 11" at over a foot and half away
- And still able to hear high tones

I've found 2 silver rings and a junk ring - all very clear
tons of coins
hitting the fence line where other machines can't run

Your advice on this forum definitely helped - but I'm also really liking the NEL coil "going where no man has gone before"...................

 

[still looking 52]

Sounds good captain Kirk, those small coils can get in tight places.

 

[jd88047]

I have the same issue. I dont think your doing anything wrong, just the coil is that good. It goes that deep into the ground. You got a hot machine, I would keep it. A small coil will get you closer. Lower sense will get you closer. But within 6 inches of a pole a target will sound off under your coil. Just swing slow, and listen.