Getting ready to build the MPP

[KRinAZ]

I got a tracker IV for $60 brand new planning on using the stick for other MD's

Sven did BH in GMT housing. http://compass-metal-detector-forum....td7600844.html
nice done...

Cool, very nice solution, I'm now on the watch for empty GMT housings...I actually own a GMT but IMHO it's right there in the very short list of the best of the VLF gold hunters - I get a target response from a .3 grain (not gram) tiny gold speck at 1 inch (about 25mm) - it's one of my test targets - and wouldn't dream of robbing anything from it...

[KRinAZ]

I bought some GMT housings. They were about $25 each;
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That's a really good idea - eBay also?

[KRinAZ]

You could use an ice scraper as a stick;
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Haha, good idea actually - would need to find ones that were all plastic...mine is sturdy but metal...

[KRinAZ]

Try this -> http://www.whiteselectronics.com/space-saver-rod-kit

Wow, I didn't know the whole pole assy could be bought at White's as a kit - very cool! & price seems fine to me - that's what I want!

[KRinAZ]

You can buy a stick for $48 (ouch) http://www.ebay.com/itm/271609965612...%3AMEBIDX%3AIT

And Coil Housing for $14 http://www.ebay.com/itm/121469795547...%3AMEBIDX%3AIT

And a box for $15 http://www.ebay.com/itm/OtterBox-Pur...item19f156f030

Or look for a cheapo detector. I got a tracker IV for $60 brand new planning on using the stick for other MD's

OK, cool, I especially like the Otterbox! - the only reason my ancient iPhone is still alive is because the Otterbox protected the landings of it's maybe 30 drops/falls, so I would really like an Otterbox waterproof housing for the electronics. I know the total solution would not necessarily be waterproof - but the electronics would be well protected!

[KRinAZ]

The voltage swing of +/-5V mentioned in the Build Document is only a guide. The TL071 rails out at about 4V, so your voltages are fine.

Oh, ok, good then!

[Silver Dollar]

I bought some GMT housings. They were about $25 each;

[kt315]

I got a tracker IV for $60 brand new planning on using the stick for other MD's

Sven did BH in GMT housing. http://compass-metal-detector-forum....td7600844.html
nice done...

[Silver Dollar]

You could use an ice scraper as a stick;

[Qiaozhi]

You can buy a stick for $48 (ouch) http://www.ebay.com/itm/271609965612...%3AMEBIDX%3AIT

Try this -> http://www.whiteselectronics.com/space-saver-rod-kit

[Silver Dollar]

OK, so now it's time to figure how to put it together into something I can use in the field...

You can buy a stick for $48 (ouch) http://www.ebay.com/itm/271609965612...%3AMEBIDX%3AIT

And Coil Housing for $14 http://www.ebay.com/itm/121469795547...%3AMEBIDX%3AIT

And a box for $15 http://www.ebay.com/itm/OtterBox-Pur...item19f156f030

Or look for a cheapo detector. I got a tracker IV for $60 brand new planning on using the stick for other MD's

[Qiaozhi]

OK, finally got parts from Mouser, swapped the bad TL071 for a new one, & step 8 checks out as working fine - my voltage swing at TP9 when adjusting Threshold is +/-4.1VDC, not 5 as the build doc says, don't know if that's an issue or not...

The voltage swing of +/-5V mentioned in the Build Document is only a guide. The TL071 rails out at about 4V, so your voltages are fine.

[KRinAZ]

OK, so now it's time to figure how to put it together into something I can use in the field - needs a box to hold the electronics, a pole system to connect the search coil, arm rests, etc. Curious what others have used to complete their project...

I picked up a Whites Classic ID for not much - thought I could remove the electronics and use it for this project - but I made the mistake of trying it out in the field and found it to be quite a nice treasure hunter, I really like it - so now I don't want to make it a donor...but something like that seems like it would work well...

[KRinAZ]

OK, finally got parts from Mouser, swapped the bad TL071 for a new one, & step 8 checks out as working fine - my voltage swing at TP9 when adjusting Threshold is +/-4.1VDC, not 5 as the build doc says, don't know if that's an issue or not...

Anyway, I then finished step 9 and, in the words of Gene Wilder, "It's Alive!", yea! it works. Cool!

The audio sounds make me laugh but IMHO the audio is quite effective. I found some small 32 ohm speakers so I'm going to try one soon to see if maybe they aren't so loud.

This MPP is in the build doc form, I'm still using the 470ohm damping resistor (will get to that soon)..., no mods done to it yet but I think I may build a second one and mod it and compare the two...or I may just mod this one...

For the coil's initial air tests, it has no reaction to my hand - even when I have my hand completely wrapped around it - so the self shielding appears to work, will know more when it is in actual use scanning the ground...and as for detection pattern - detection distance is surprisingly uniform all around under the coil and to the sides. I expected a clear cone shaped detection pattern but the cone effect is actually very slight - perhaps a .5" (13mm) deeper detection in true center, and it is very easy to pinpoint a target with the nose or heel of the coil where it is more pointed. I look forward to making a video of it in use on the ground when I get to that point with this project...

[KRinAZ]

Count me in for two housings; I would prefer the Minelab 24mm spacing on the mount tabs. The wider base is stronger and is the standard for most Pulse Induction after market coils except for Whites. Spacers/washers can be used to fit with the 19mm shafts. He may be able to make both widths by having interchangeable tabs on his mold form. The inside height should be a minimum of 1".

Good, will do Chet, & 24mm would be fine with me also - all my experience is with VLF units so I didn't know PI's had a different mount. My understanding is that a ML or Coiltek coil can be put on a Whites PI detector, so their PI units must be 24mm also. I agree that using the most popular PI coil mount would be a good thing! When I get some time I'm going to experiment with making a mold for DBFLowers, I'll make sure I get my hands on a ML or Coiltek coil and try to duplicate the mount tabs and the positioning.

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