Commercial coil?

[bicter]

Hi all,
About to commence building the MPP. Can I have advice on which commercial coils people have used successfully on this detector?
I have several commercial coils sitting here, a standard AT Pro and several coils I use on the GPX5000.
Thanks
Terry

[Qiaozhi]

Hi all,
About to commence building the MPP. Can I have advice on which commercial coils people have used successfully on this detector?
I have several commercial coils sitting here, a standard AT Pro and several coils I use on the GPX5000.
Thanks
Terry

The Garrett AT Pro is a VLF detector, and the coil will not be suitable for a PI.
The GPX5000 coil might be OK. Depends which ones you have available.

You can easily make your own mono loop coil for the MPP to use for initial testing.

Remember to follow the Build Document carefully, and test each stage as you build it.

[kt315]

Qiaozhi, we do not know he has original gpx5000 or chinese crap gpx5000. so your answer is not fully imaging situation =)

http://md-arena.com/kitajskij-minelab-poddelka/
http://www.minelab.com/emea/consumer...article=178728

[kt315]

http://www.geotech1.com/forums/showt...X5000-question

[Chet]

Hi all,
About to commence building the MPP. Can I have advice on which commercial coils people have used successfully on this detector?
I have several commercial coils sitting here, a standard AT Pro and several coils I use on the GPX5000.
Thanks
Terry

Hi Terry

I have used the Coiltek 6" X 9" Sade Mono coil on the Minipulse. It works quite well. Most of the commercial coils for the GPX 5000 have similar characteristics. They are usually around 300 uH with less than 1 ohm resistance and capacitance is from 150 pf on the small coils to 450 pf on the larger coils. They don't recover as fast as the Basket Wound coil that is shown in some of the other threads which has less than 100 pf capacitance.

Have a good day,
Chet

[Qiaozhi]

Qiaozhi, we do not know he has original gpx5000 or chinese crap gpx5000. so your answer is not fully imaging situation =)

That's true ... which is why I said "The GPX5000 coil might be OK. Depends which ones you have available."
If it's a "Chinese crap" version, then it could even be a VLF in disguise.

I guess we'll have to wait for bicter to give us an update.

[bicter]

Thanks all for the replies.
The GPX coils are the genuine article, purchased from several reputable dealers here in AU.
I have Coiltek 14" & 16", Minelab OEM 11" mono & DD along with Detech 15x9".
I'm hoping to use the 15x9" coil on this project.

Qiaozhi, thanks for the additional information and Chet, it's good to hear that your Sadie works well.
Are you able to give an indication of the sort of improvement I could expect if I was to make/use a basket coil?
This detector is intended to use at the beach on wet sand.


Regards
Terry

[Chet]

Hi Terry

KRinAZ has some Basket Wound test results here;
http://www.geotech1.com/forums/showt...454#post206454

I think one of your commercial coils will work fine on the beach. I don't think the Basket Wound coil will gain much at the beach. You will fine a big difference between wet and dry sand. Be prepared to dig a lot of hair pins, fish hooks, lead sinkers and pull tabs.

Have a good day,
Chet

[godigit1]

Hi Terry,
The minelab coils are hit and miss as to weather you will get best performance. I used the joey the platypus and 11 dd minelab with the best results from the platypus. But I also have a TDI so I tried the miner John folded mono and the 12 inch dual field. By far the best match so far is the TDI dual field. Ive just packaged my mini pulse and had it out to the beach for two hunts. The dual field with the minipulse running at 8us ( can sample down to 5us) sample runs stable in the dry and will hit some pretty small items (Staples and such). In the wet I have to turn sample delay up to about 12 us.
Both the tx and rx wires have individual shielding so thats a plus as well very stable.
That being said my home made 5 x 9 basket coil is my most sensitive.
Depends on what you intend to hunt for.
Good luck with your build.
digit

[Qiaozhi]

Hi Terry,
The minelab coils are hit and miss as to weather you will get best performance. I used the joey the platypus and 11 dd minelab with the best results from the platypus. But I also have a TDI so I tried the miner John folded mono and the 12 inch dual field. By far the best match so far is the TDI dual field. Ive just packaged my mini pulse and had it out to the beach for two hunts. The dual field with the minipulse running at 8us ( can sample down to 5us) sample runs stable in the dry and will hit some pretty small items (Staples and such). In the wet I have to turn sample delay up to about 12 us.
Both the tx and rx wires have individual shielding so thats a plus as well very stable.
That being said my home made 5 x 9 basket coil is my most sensitive.
Depends on what you intend to hunt for.
Good luck with your build.
digit

This is all good advice for MPP builders.

12us sample delay is about what I'd expect on a wet salty beach.

[bicter]

Again, thanks all for the responses.
I've been away for a couple of days to escape the heat, now catching up on correspondence.

Time to learn all about coils

Regards
Terry