Best detector to build.

[grandpastar]

Hello everyone. I'm interested in gold prospecting and meteorite hunting. I also want to build my own detector from a kit. Which one would you guys recommend, or should I build two? What about one unit with two separate "brains" I can switch between?

[baum7154]

Are you an electronics hobbyist/professional? Some kits are more suited to beginners and others are suited to advanced builders who have resources like an oscilloscope, signal generators, frequency counters, LCR meters, etc.

How small of gold will you be seeking? Small gold represents some of the most challenging of targets. Gold in the 5 to 10 grain range requires a very fast coil and very short sampling intervals assuming a PI detector is what you will build.

Regards,

Dan

[grandpastar]

I'm more of a beginner than a pro. I don't have any fancy test equipment. I'm looking at one of the Silverdog kits or something similar. I suppose a good "middle of the road" unit is best? I do want plenty of power. As far as the mechanical side of things I can build anything.

[baum7154]

I would recommend the Minipulse analog kit as it is the only one designed with a 2 stage preamp that will allow you to detect small gold in the 10 grain range and doesn't require a lot of equipment. Other detectors require modification to a 2 stage amp. For a coil I would recommend the spider wound round coil detailed in the CHANCE PI thread of the COILS FORUM. It is quite fast and has a degree of self shielding. Build it for small gold in an 8" diameter with about 300 to 320 uh of inductance using 30 to 32 turns of #24 600 volt Teflon insulated stranded wire from EBAY on the LEXAN form detailed in the thread.

Good Luck!

Dan

[grandpastar]

Thanks Dan. If I build the minipulse I see that the board size is 3.5 inches square. What is the minimum size I should build the control housing? What materials would be acceptable or unacceptable?

[baum7154]

Thanks Dan. If I build the minipulse I see that the board size is 3.5 inches square. What is the minimum size I should build the control housing? What materials would be acceptable or unacceptable?

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In my opinion a metal housing or enclosure is a must as it helps to keep interference to a minimum. I have not built the Minipulse but my CHANCE PI board measures 3 1/2" X 3" and the enclosure I used is 5 1/4" long by 4 5/8 wide by 2 1/4 high. You could use a slightly smaller enclosure I think since Minipulse does not have a LED display. I don't put the batteries in the enclosure as they are used as a counterbalance on the boom placed below my forearm at the far rear position on the boom. Pictures of the CHANCE PI are in the Tech Forum -- 'Chance PI build' thread Posts 31 & 32 if you would like to see what I did for the enclosure and boom.

Good Luck

Dan

[grandpastar]

Thanks for your help Dan!

[CAS]

I have built the MPP and its a great kit to learn on. It has an easy to follow construction guide and there are plenty of people on here that will help you out if you have difficulty. It will detect gold and (thanks to the show 'Meteorite Men' I now know that meteorites are iron based) I am sure it will pick up meteorites as well.
By using different size coils you will be able to achieve different depths - bearing in mind though that bigger coil = greater depth = less sensitivity to small items whereas small coil = very good on small shallow targets
If you are willing to learn and experiment with electronics, the MPP is a good circuit to modify.

[grandpastar]

Thanks CAS!

[grandpastar]

I ordered my MPP kit from Silverdog.co.uk. I bought a few other things as well. I'm sure I'll have a few questions later too.

[grandpastar]

My MPP kit came today. My wire for my coil should be delivered Thursday. I guess I know what I'll be doing this weekend.