Pulling Hair Out!

[pulper]

With all the schematics out what would be the best for coins and gold?
Matters not how sofisticated if I have the schematic can build from that.

[mikebg]

With all the schematics out what would be the best for coins and gold?
Matters not how sofisticated if I have the schematic can build from that.

Pulper, remember that your coins and gold nuggets are buried in soil that creates interferencing, confusing and misleading signals. With all the soils out, what would be the best schematic for a metal detector?
Mike BG

[porkluvr]

With all the schematics out what would be the best for coins and gold?
Matters not how sofisticated if I have the schematic can build from that.

If you are willing to dig everything then there are several PI schematics and projects to choose from. If you want to possibly save some unnecessary digging (but you will have less detection depth) then build one of the IB detectors.

There are several Tesoro IB detector schematics and Fisher, and even the Fisher Goldbug1 on this site but I cannot vouch for the accuracy of the GB1 schematic.

Tesoro Lobo is a gold detector that is also good for coins but you would need to pick through several schematic versions to try and arrive at the best components to use. The various "clones" are somewhat different. Oftentimes, bugs creep into the reverse engineered schematics and they can be hard to get out.

If you have some electronics knowledge and an oscilloscope, then you have a fair chance of getting something to work. If you don't, then your chances shrink considerably.

You'll also need to find a PCB layout or else make one yourself for whatever you choose.

[pulper]

I have only found one schematic for the lobo and it is 1984 I think. Where can I find more. I do have a fair knowledge in electronics especially repair of anything. I am still learning the theary to be able to develope my own. I can decipher schematics and also design and build my own boards. My only drawback is to build the coils. None of the schematics tell the diameter (guage) of wire and turns. I do have an osciloscope but not a frequency meter (my next thing to get).

Thanks for your help porkluvr

[porkluvr]

Do a search on "Lobo" (threads). I think that the most activity was in a thread called "Lobo Improved" but there is also "TESORO LOBO SCHEMATICS" and possibly some other threads with good info...

Beware there is some bad information and I admit that I am responsible for my share of it.
Don't believe the first diagram you see because it may simply be a rehash of previous errata.

Here is a short database of coil parameters that includes two different Lobo coils:

http://www.geotech1.com/cgi-bin/page...oils/index.dat

Before I forget I would like to repeat some advice that I think is pretty good.
If you want to tackle a project like the Lobo it might be a good idea to purchase a factory coil to use. There are a lot of subtle things that can go wrong building and aligning an IB coil. You will almost certainly have problems but that way you can probably rule out the coil as the source. (Thanks to Qiaozhi.)