hammerhead home made PI detector project

hi,
i am going to give this project a go to get a better understanding of the workings of a PI detector. this is obviously not going to be used for gold prospecting and other than testing probably wont get used but more for the techno side of things.


http://www.geotech1.com/cgi-bin/pages/common/index.pl?page=metdet&file=projects/hammerhead/index.dat


I have done a few projects now and have a fairly good understanding of electronics so it will be a very interesting electronic project to combine with detecting. i have 2 boards and enough components to make 5 or so but will start with the HH1 and look at the mods for GB etc as they develops.
Unfortunately i cannot actually start assembly the board till im in the new shed early next year but will keep all interested informed of the progress of the coil and shafts etc as i get time.
any insight will be greatly welcome, as i said i do have some knowledge and experience in electronics but in reality its pretty well self taught and very limited.

To Be Continued.....

cheers