Don Lancaster's Metal Detector Design

[Randy Seden]

I was going thru all the artilces on Don Lancaster's site and came across his idea for a VLF metal detector using a NE5520 or NE5521 LVDT Signal Conditioner IC. This design looks superior to the one's that use a PLL and he mentions at the end of the article that with a second 5520 you could add automatic ground tracking and the "native" soil backround cancellation. This is in March 90' issue of Hardware Hacker at http://www.tinaja.com and click on "Hack". Would be kinda neat to build on of these at 20KHZ (max freq. of the LVDT chip) for gold prospecting. Any thoughts's out there?

Randy Seden WD6ELU
Simi Valley,CA.

[Carl]

Re: Don Lancaster's Metal Detector Design

Thanks for the info. I had searched through Don's site (one of my all-time favorite web sites!) a while back but missed this, probably because it's in the Hacker collection. I downloaded the 3 collections but haven't had time to look at them.

[Randy Seden]

Re: Don Lancaster's Metal Detector Design

3 collections, I must of missed 2! Which ones did you download as I only saw the March 90' article?

Randy Seden

[Carl]

Re: Don Lancaster's Metal Detector Design

There are 3 PDFs that contain a massive collection of Hardware Hacker articles:

Hackar1.pdf - 1068K

Hackar2.pdf - 2190K

Hackar3.pdf - 1412K

Tons of stuff to read!

- Carl

[Randy Seden]

Re: Don Lancaster's Metal Detector Design

Ok, you meant the collection of past Hacker articles in general. Yes, I went thru every single one of them! Good stuff to be sure and lot's of meaty but down to earth stuff. Too bad that Forrest Mims doesn't put his stuff on the web, WOW there's another practical down to earth kind of designer!

Randy Seden-WD6ELU
Simi Valley,CA.