bulid your own Tesoro

Hi all. i am a real greenhorn - not been outside yet. Decided I wanted to build a detector and afetr a fair bit of searching, picked the Tesoro Bandido (but for trademark sake, mine is called a Bandodo). Lots of circuits about for this one BUT, they all miss a vital part. There is a third coil (bucking coil) not shown on any schematic I have seen. It is wound around the RX coil, 1/4 the number of Rx turns, and is wired in series with th Tx coil. This extra coil must be so placed as to be 180 degrees out of phase - just turn it over if it does not work. Once you have this things start to happen! I changed all the ICs for types in my junk box and a few Rs and Cs that don't really matter. So far it all works. Need to finish it before going out to the fabled UK gold fields (they are in Injun country - we have a lot of them over here). I will post again when I have discovered some Saxon treasure.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,35073.msg212982.html#msg212982

What searchcoil information did you use ? The original German files or the English . The bucking information was posted with one of those files ? The other option is just make a DD configuration , it will be easier to wind .

HH...............Eugene

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,35073.msg212993.html#msg212993

Coil ? Hah! I made a LOT of coils and today, by accident....Made a 9" Tx and a 5" Rx and a buck coil around the Rx (turns by calculation, not guessed.
Now then. Since my Tx coil is 9" I calculated the diam. Then I got an old wooden slat from a blind, made a U shape in each end, spaced at half the circumf. next, real easy to wrap the coil nice and tight. Test for frequency to be 2 * the required F - so for 10Khz I measure 20KHz. Why ? Snap the wood and remove the coil, bind it with tape and open into a circle. Then measure F, it will be half ie 10KHz. Same method for Rx and Buck.
Placed buck on top or Rx and tuned for a null with a scope - took about three turns off - not bad for the maths. Then I found something odd...as I moved the Rx and buck, so the null changed (yes, I know why)...so....fixed the Rx in the middle of my head, then the Tx but by changing the shape here and there got a total zero null  - and the range on the bench is brilliant!!! Still finishing it, hope to post some pics.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,35073.msg213405.html#msg213405

Hello, I have seen a lot of the USA, spent three weeks on Scottsdale, went to the Canyon, Tombstone, Nojales and Cabo San Lucas too. Loved Rawhide, the river boat trip and a place called Greasewood Flats. Great times.

Posted on: February 17, 2012, 02:01:08 PM

---

Hi and yes, i did the math and got things right but it was the physical alignment in the head that nailed it. I work (like at work) in the 800Meg band where things are real spooky. In time I plan to add a micro and do a bit of DSP stuff - I will be able to flip between analogue and digital modes - I think the micro version will be way better.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,35073.msg213429.html#msg213429

I use a lot of the 16F, mainly 84, 73, and 856 -they do most of what I want. I also use the 18F8722 which runs at 40M and does a whole lot more. Good luck - it should be quite easy to do if you interface into the detector itself.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,35073.msg213596.html#msg213596