Geotech - Technology for Treasure Hunting

Hammerhead

by Carl Moreland

Hammerhead is a Pulse Induction (PI) metal detector. The primary purpose of this design is to provide the experimenter a platform with which to learn the operation of PI. For that reason, all operating parameters are variable through hardware controls, so that the user can test performance for a variety of settings. Hammerhead is not intended to compete with commercial PI detectors in performance; however, the design is very similar to many mainstream PI detectors, so it is possible to get similar performance.

SMT PC boards are available. These are a high-quality surface-mount PCB (two-sided) using SOIC chips and 0805 passives, with solder mask and silkscreening. The SMT boards are a small 2.3 x 2.0 inches, ideal for making a probe, or even mounting in a headphone cup, such as the Headhunter PI.

NOTICE: I have no more standard through-hole PCBs. Please DO NOT place orders for these, because I will not be able to process your order. I have only SMT boards. The GERBER files for the through-hole board are also posted below, so you can have a PCB made if you wish. I have no plans to make any more thru-hole boards, sorry.

In the US, Canada, and Mexico PC boards (either type) are $10 each shipped. For most everywhere else, they're $12 USD. For US orders, I accept cash, check, US Postal money order, or PayPal. For everywhere else, I prefer PayPal, but will accept cash as long as it factors the current exchange rate, and is in bills (no coinage). Mail payment to:

Geotech
P.O. Box 666
Sweet Home, OR 97386

Paypal ID is carl@geotech1.com.

The Hammerhead construction article:

Hammerhead Article (PDF-1114K, 300dpi) - Rev 1.5 -- 21 July 2006

Here is the schematic & placement diagram for Rev D. Please note that the construction article above is valid for the Rev C PCB. Differences are minor; compare with the Rev C schematics below, or visit the forum for more info.

Full schematic & placement (PDF-671K) - Rev D1 -- 07 Feb 2007

There are three schematics currently available: the full schematic has everything that is laid out on the PC board, including optional components. The "Option 1" schematic is a little simplified, and is set up with VCO audio. The "Option 2" schematic has non-VCO audio. The schematic PDF files also include a parts-placement diagram. These files are for the through-hole PCB:

Full schematic & placement (PDF-345K) - Rev C2 -- 31 May 2006

Opt1 schematic & placement (PDF-338K) - Rev C2 -- 31 May 2006

Opt2 schematic & placement (PDF-334K) - Rev C2 -- 31 May 2006

These are the schematics & parts placement diagrams for the surface-mount PCB. They are almost identical to their corresponding through-hole versions, except that there is no active turn-off option for Q3 (i.e., R7, R8, and R15 are omitted), and Q11 is inadvertently labeled Q4 on the SMT PCB.

SMT Full schematic & placement (PDF-210K) - Rev C2 -- 31 May 2006

SMT Opt1 schematic & placement (PDF-194K) - Rev C2 -- 31 May 2006

SMT Opt2 schematic & placement (PDF-192K) - Rev C2 -- 31 May 2006

Here are the PCB layouts for both Rev C & Rev D, please note that it is 2x. Also the Gerber files for both revs, for those who want to import them into their CAD program for modification:

Through-hole PCB Layout (2x) (452K GIF, 600dpi) - Rev D

Through-hole PCB Gerber files (180K ZIP) - Rev D

Through-hole PCB Layout (2x) (246K GIF, 600dpi) - Rev C

Through-hole PCB Layout (2x) (PDF-287K, 600dpi) - Rev C

Surface-mount PCB Layout (TIFF) (113K ZIP) - Rev C

Through-hole PCB Gerber files (133K ZIP) - Rev C

Surface-mount PCB Gerber files (79K ZIP) - Rev C

Click Here for older board revisions.