F75 Big Coil

[TheCaribbeanDigger]

Hey good folks TNet! I have a Camo editon F75, I have a couple of sites which I'm probably guessing might have the potential to have deep targets. I have the stock 11" DD and 5" coils. Which coil do u recommend that can reach a coin at 16+ inches? NEL, just to mention a brand, has some huge coils. I would love to have a coil not bigger than 14". Iv'e heard those 15"+ coils are heavy as a brick!

 

Amazon Forum Fav 👍

A History of Mining on the Kenai Peninsula, Alaska - Grab it through Amazon!

[Welgund]

Getting a coin at 16in in any soil with any size coil is not going to happen I would say. Possibly a jar of them though. This is depending if your soul is decent or not also.

 

[Charlie P. (NY)]

Any coil over 15" might not notice single coins at even 10". Depends on your soil and other factors.

If I knew of a coil that would find all coins at up to 16" I'd have one. But where I hunt I often do better with smaller coils to shoot through the trash and scrap. I've been running a NEL Sharpshooter (DD) on my F-75. So far 10" is about the limit on coins. About the same as the stock flounder skeleton coil.

 

[Loco-Digger]

I have the NEL 12 x 15 butterfly coil. It does add weight and if I plan on swinging it for more than an hour I use a make-shift harness to null the weight. Big coils are great in target sparse areas, but do not work well in trashy areas.

 

[TheCaribbeanDigger]

Getting a coin at 16in in any soil with any size coil is not going to happen I would say. Possibly a jar of them though. This is depending if your soul is decent or not also.

Yes I know what u mean. Typically our soil here is good and not highly mineralized. The reason is that the majority of the sites o go to have been highly altered. What I mean is that our vegetation is very agressive (it grows very fast) and the majority of the land owners tend to use heavy machinery to clean up their properties and move 1-3' of the top soil to other places and stuff like that. When I see the ground of sites that hold a lot of history say 100-200 years and look down you don't see, glass, pieces of old pottery ect. and when u swing your detector theres hardly any iron signal. There are spots within the property that are littered with iron signals but you can tell is because the top layer of soil has been bulldozed or plowed and taken to near or far areas. Ive dug wheaties 8" down while I found an 1870 copper spanish coin just lying on top! Both coins where found a couple of meters between them!
This can only be explained by the situation of the grounds being worked by heavy machinery! Thats why I want to get a big coil just to make sure I can go pretty deep to get stuff that could probably got deeper by any circumstance it might of faced.

 

[HighVDI]

16 inches? Makes me laugh when people claim to find coins at depths like these. I guess an open field would be the best luck with that since masking will be pretty much minimal. I've dug a big flat button at 10+ inches with my f75 without bp. Still rang up fairly strong, and the vdi was right there. Also dug a barber quarter at closer to 12" and that signal was definitely faint! Still a solid visual display though. Both were with the stock DD coil. I've used my 15" coil on it recently. Wasn't too bad for about an hour then my shoulder felt like mush. Definitely seemed deep though. Especially for the smaller targets.

 

[TheCaribbeanDigger]

So, a deep coin say 12"-14" will sound like iron? Perhaps a high tone mixed with an iron tone? I'm just looking for all the help and info I can get...

 

[Charlie P. (NY)]

Not necessarily. A coin should give a high tone. Iron a low tone. The F-75 has all kinds of settings and several display sections. The Fe3O4 scale will let you know if iron or iron oxide is under the coil. You may just get a faint sound, but the target scale is on a separate circuit (like a second detector) and a higher reading indicated coin metals.

Here is a scale of the display for common US coins and some odder ones.

 

[HighVDI]

I've dug a few deeper silver dimes that gave out an occasional iron grunt in between swings. One thing I noticed on those targets were the vdi numbers never dropped....just the audio. I've been digging all my deeper signals lately just to try and learn more about my machines tendencies. VERY rarely will a deep falsing nail stay up high in the visual numbers. I usually see 70's, and 80's on the screen, then every 3 swings back and forth a 20 something pops up and there's a few iron grunts in the mix. My silvers never dropped.

 

[cactusman]

The gains of large coils (say above 10 inches or so), are marginal on coin-sized objects. In highly mineralized soil sometimes larger coils get less depth. The real gains to be had with large coils are in cache hunting, where the target is bigger. Your best bet for getting deeper coins is using the all-metal mode.