F2 And 11" DD Coil

[A1MTD]

F2 and 11" DD Coil

Recently a friend bought a New 11"DD coil for his F2 detector, after a few days of detecting and testing with it he found it had poor results compared to his 8" Coil that came with the detector. In many instances he found that it Did Not detect coins any deeper than the original coil even with full sensitivity settings. Also he found it could not even pick up a Silver quarter at 5" deep like the 8" coil could in discriminate mode, even low settings would block the Silver quarter out. He also found to pick pull tabs more than what the normal 8" coil would. After all this he feels the 11" DD coil has been a waste of money and was wondering if the 10" concentric coil would give him more depth than this thing does. Anyone else find any similar findings with the F2 and the 11" DD coil ? This is not normal even though it does detect some Junk items it should give a inch or so more depth on coins than the 8" coil and still should be able to pick up Silver quarters at 5" or so even with low discrimination on. What do you think? Is their a fault with his new coil? Should he send it back for another one ? Should he purchase the 10`to replace it ? Any comments appreciated.
A1MTD/b]

 

[Dave J.]

Could be a bad coil. Or maybe coincidence for those particular targets, DD's don't see things exactly the way concentrics do. However, are you sure it was the right coil? If it was specified for the early F5's it's the wrong one. The one you want is specified for the F2/4 and most BH's.

--Dave J.

 

[A1MTD]

Dave
Yes I ordered it for him. it was labled F4 with white tag in bubble wrap when it came from my supplier. I'm surprised at the findings myself. I want to do some test with it, I have a couple other F2's here and a F4, maybe I can try the same coil on these other F2's or try the F4's -11"dd coil that came with the F4 and see if it does the same thing. I'm hoping to find out what the results after testing from my test site here. I hope that he didn't sell it on ebay will check to see if he still has it so we can do some testing myself.
A1MTD

 

[Dude]

What where the ground conditions when using the 11" DD and 8"? Ground conditions play a big part in the performance of a coil.

Doing an air test will give you a bench mark as to a coils performance. That would give you a starting point into their performance and allow you to compare the two.

On my F2 a clad dime will air test at 6.5" with the 11" DD coil with sens maxed. Same set up but in moist ground I've easily hit clad dimes at 8", in dry ground that hasn't seen rain in weeks I'll be lucky to find them at 6".

Hope it helps

 

[A1MTD]

Hey Dude
That I will have to find out not much rain before he tried it that I'm sure, he lives beside a lake, that ground I'm surmising is regular dirt with many garbage targets as it was a former camp ground before he told me. I don't really know just from his phone call to me that I will have to check out myself. I know air test are meaningless no comparison to different ground conditions one encounters. Here most grounds have heavy minerals the province had major Ice age movement and bedrock is not far away in most areas, Heavy mining areas of Gold / Coal / Salt / Gypsum / Copper and many others surround us along with heavy salt water beaches nearly surrounding us on all sides. We have to put up with many minerals and hard grounds to detect. I will get to the bottom of this one way or another, I suspect as Dave mentioned a Bad coil which can happen from time and again. After all in the air or ground should not discriminate out a Silver quarter \t low disc settings. I remember retrieving quarters with my 1265X in clay ground several inches deep many times years ago with higher settings than what he was using with my 8" coil. Thanks for answering I will follow up on this if he hasn't resold it yet. Thanks
A1MTD