| 07/28/10 | - | Colorado Gold Sticks report (LRL/Reports) |
| 01/07/10 | - | Article on LRLs and eBay Feedback (LRL/Info) |
| 12/31/07 | - | Geotech now has its own domain name, www.geotech1.com. |
| 12/21/06 | - | Article on making fast PI coils (Metal Detector/Projects) |
| 11/06/06 | - | Add'l Schematics posted (Metal Detector/Schematics) |
| 08/20/06 | - | Article on Coil Basics (Metal Detector/Info) |
| 08/10/06 | - | Article on Induction (Metal Detector/Info) |
| 05/23/05 | - | Notes on Bill Floto's LRL (LRL/Reports) |
| 03/13/05 | - | All-new forums! |
| 12/31/04 | - | Created a database of coil parameters (Metal Detector/Info) |
| 12/10/04 | - | Added Jim Koehler's proton mag report (Magnetometer/Info) |
| 12/10/04 | - | Updated the various Magnetometer sections (Magnetometer) |
| 12/06/04 | - | Patents added (Metal Detector/Patents) |
| 11/19/04 | - | Ranger-Tell Examiner report (LRL/Reports) |
| 06/06/04 | - | Updated Hammerhead PI page, added SMT files (Metal Detector/Projects) |
| 05/20/04 | - | Updated Hammerhead PI page (formerly PI-1 project), added Gerber files (Metal Detector/Projects) |
| 04/09/04 | - | Updated the Resources Page (added some good PIC links) (Misc/Resources) |
| 04/09/04 | - | Jim Thomas lawsuit report (LRL/Info) |
| 04/01/04 | - | Electroscope 301 report (an appropriate item for April Fool's Day, eh?) (LRL/Reports) |
| 03/27/04 | - | "Matchless Metal Locator", by Thomas Scarborough (Metal Detector/Projects) |
| 02/15/04 | - | Treasure Scope "Quad" report (LRL/Reports) |
| 01/05/04 | - | "Build the Frisker", by Sheets & Graf (Metal Detector/Projects) |
| 12/16/03 | - | Added a "References" page to all the major sections of the web site. |
| 12/02/03 | - | "Construction of Coplanar Search Coils", by Dave Emery (Metal Detector/Projects) |
| 11/25/03 | - | "Build an Induction Balance Metal Locator", by John Clarke (Metal Detector/Projects) |
| 11/21/03 | - | "Build You Own Sonar System", by Lou Garner. (Geophysics/Projects) |
| 10/27/03 | - | "Build a Metal Locator", by Robert Kreiger (Metal Detector/Projects) |
| 10/14/03 | - | Misc Metal Detector Circuits, by Charles Rakes (Metal Detector/Projects) |
| 09/25/03 | - | ETI561 crystal BFO, by Phil Wait (Metal Detector/Projects) |
| 09/09/03 | - | 2-part article on detector circuits, by Charles Rakes (Metal Detector/Projects) |
| 08/26/03 | - | Posted rev 0.8 of the PI-1 project article (Metal Detector/Projects) |
| 08/10/03 | - | Lots of patents added |
| 08/08/03 | - | "Simple, Sensitive Geiger Counter" by David Tilbrook. (Geophysics/Projects) |
| 07/21/03 | - | ETI1500 article posted, pretty good VLF/TR design (Metal Detector/Projects) |
| 07/11/03 | - | "Revealer" article posted (Metal Detector/Projects) |
| 06/09/03 | - | Commercial schematics page added (Metal Detector/Schematics) |
| 06/08/03 | - | LectraSearch X-60 report (LRL/Reports) |
| 06/01/03 | - | "All About Batteries" (Misc/Info) |
| 05/30/03 | - | Dowsing for Raffle Tickets (LRL/Info) |
| 05/29/03 | - | "Tools & Techniques in Radiometric Exploration" by Malcolm J. Plunkett. (Geophysics/Info) |
| 05/09/03 | - | Scantrak 18 Golf Ball Finder, funny look at another scam. (LRL/Reports) |
| 05/08/03 | - | Posted rev 0.7 of the PI-1 project article, plus Option 2 (Metal Detector/Projects) |
| 04/29/03 | - | ETI549 Induction balance project, Australian version (Metal Detector/Projects) |
| 04/28/03 | - | Posted rev 0.6 of the PI-1 project article (Metal Detector/Projects) |
| 03/28/03 | - | Deep-seeking metal locator, by Wait & Harrison (Metal Detector/Projects) |
| 03/12/03 | - | Posted rev 0.5 of the PI-1 project article (Metal Detector/Projects) |
| 03/09/03 | - | "Expermenting With Magnetic Sensors", by Joseph J. Carr (Magnetometer/Info) |
| 02/20/03 | - | Electroscope Model 20 report (LRL/Reports) |
| 02/20/03 | - | Earth resistivity meter (from ETI) posted (Geophysics/Projects) |
| 02/18/03 | - | New parts-placement diagram for PI-1 |
| 02/07/03 | - | "Exploration Archaeology" article posted (Geophysics/Info) |
| 02/05/03 | - | Posted rev 0.3 of the PI-1 project article (Metal Detector/Projects) |
| 01/23/03 | - | Posted "Houndog" IB project article (Metal Detector/Projects) |
| 01/21/03 | - | Posted rev 0.2 of the PI-1 project article (Metal Detector/Projects) |
| 12/18/02 | - | Posted alpha rev of the PI-1 project article (Metal Detector/Projects) |
| 11/14/02 | - | Magnetometer article by Lawrence (Magnetometer/Projects) |
| 10/31/02 | - | Proton Magnetometer article by Marriner (Magnetometer/Info) |
| 09/30/02 | - | Seriously major overhaul of the Geotech web site. |
| 07/30/02 | - | Added section for patents pending on the patents page. |
| 06/27/02 | - | Inside the LectraSearch report (LRL/Reports) |
| 12/06/01 | - | Inside the Electroscope report (LRL/Reports) |
| 12/06/01 | - | VR-800 Addendum (LRL/Reports) |
| 12/04/01 | - | LRL Challenge. |
| 08/22/01 | - | Posted "Underground Survey Meter" by Harold Pallatz. |
| 08/03/01 | - | Posted "History of Metal Detectors" by Roy Roberts. |
| 07/29/01 | - | Popular Mechanics article showing a WWI mine detector (History). |
| 07/29/01 | - | Added a new "History" page to metal detectors. |
| 07/22/01 | - | Dowsing/LRL Q&A. |
| 06/24/01 | - | Posted P.J. Wales' "Sandbanks" PI detector. |
| 05/19/01 | - | Posted Mark Stuart's "EE Treasure Hunter" PI detector. |
| 04/29/01 | - | More patents, also corrected Delphion links. |
| 04/28/01 | - | Posted "Metal Detection" (basics). |
| 03/27/01 | - | Inside the VR-800 report (LRLs). |
| 03/22/01 | - | Coil Winder project. |
| 02/27/01 | - | More patents... |
| 02/23/01 | - | "Electronic Metal Locators" by Don Lancaster. |
| 12/28/00 | - | Posted "ETI 549" IB detector. |
| 11/15/00 | - | Posted "Shadow" VLF/TR-disc. detector from ETI. |
| 11/15/00 | - | Posted 150dpi version of the Huggard Mag. |
| 10/27/00 | - | Posted the Huggard Proton Magnetometer design. |
| 10/24/00 | - | Gerhard Fisher patent (1937) added. |
| 10/14/00 | - | Twin Loop Treasure Seeker (PI) by Robert & David Crone. |
| 09/28/00 | - | Part 3 of the Magnum IB article added. Parts 1 & 2 reformatted. |
| 08/17/00 | - | GoldPic PI detector by Trevor Hill. |
| 07/25/00 | - | PLL detector by Kamil Kraus. |
| 06/26/00 | - | More patents. |
| 05/26/00 | - | How to use a sluice article posted (Misc). |
| 05/26/00 | - | Updated links in most sections. |
| 05/23/00 | - | Induction Balance detector by Andrei Chtchedrine. |
| 05/23/00 | - | Patents can now be downloaded in PDF format. |
| 05/22/00 | - | Posted "How to Build a Dry Washer" in the Misc section. |
| 04/16/00 | - | Rev 1.2 of Fluxgate Magnetometer article, new sensor mounts. |
| 04/08/00 | - | Posted article on multilayer air-cored coils. |
| 01/25/00 | - | Minor revisions to "Building LRLs" and "Build an MFD". |
| 01/11/00 | - | Rev 1.1 of Fluxgate Magnetometer article, minor clarifications. |
| 01/10/00 | - | Corrected circuit for "Build an MFD". |
| 01/09/00 | - | Posted preliminary "Build an MFD". |
| 01/09/00 | - | Updated "Building LRLs". |
| 12/11/99 | - | Added a Statistics Calculator in the LRL section. |
| 12/02/99 | - | MFD offer posted. |
| 11/06/99 | - | Gavin Cheeseman's Metal Detector article, Part 2 posted. |
| 10/23/99 | - | Gavin Cheeseman's Metal Detector article, Part 1 posted. |
| 10/16/99 | - | Final version of my Fluxgate Magnetometer article posted. |
| 09/30/99 | - | Revised version of my Fluxgate Magnetometer article posted. |
| 09/19/99 | - | Preliminary version of my Fluxgate Magnetometer article posted. |
| 09/12/99 | - | Gavin Cheeseman's Magnetometer article, Part 2 posted. |
| 09/07/99 | - | Gavin Cheeseman's Magnetometer article, Part 1 posted. |
| 08/16/99 | - | Correction to Magnum IB design. |
| 08/05/99 | - | Magnum IB design (VLF/TR disc) posted. |
| 07/31/99 | - | The mapdowsing contest has now begun! |
| 07/21/99 | - | Set up the Side Scan Sonar project, volunteers wanted! |
| 07/21/99 | - | Posted PIC code for the Stuart PI design. Thanks, Mark! |
| 07/15/99 | - | Posted the "Phaser" TR design. |
| 07/14/99 | - | Part 2 of the Corbyn PI article is finally up. I will, sometime in the near future, rescan part 1 and combine everything. |
| 07/13/99 | - | Reformatted and expanded the patents list. |
| 06/20/99 | - | The Tech Forum now supports image uploads. Please click the FAQ or Help in the Post-form for more details. |
| 06/13/99 | - | PC Board techniques posted (Misc section). |
| 06/08/99 | - | Mark Stuart's Microcontroller PI design posted. |
| 06/06/99 | - | Added some misc stuff to the Misc page, mostly DIY projects. |
| 05/27/99 | - | Buccaneer IB design posted. |
| 05/12/99 | - | Earth Resistivity Meter, Part 2 posted. |
| 05/11/99 | - | Earth Resistivity Meter, Part 1 posted. |
| 05/04/99 | - | Coinshooter IB design posted. |
| 05/01/99 | - | Jetco Treasure Hawk design posted. |
| 04/27/99 | - | Posted the EDN BFO design. |
| 04/21/99 | - | Posted a two-box IB design. |
| 04/20/99 | - | Finally got a BFO theory paper done. |
| 04/16/99 | - | It's not quite finished, but I added the "Building LRLs" writeup. So build yourself an L-rod, grab a shovel and dig, and then make up your very own theory of empty holes. |
| 04/15/99 | - | Updated the patents list. |
| 04/14/99 | - | Posted the ProScan PI detector. |
| 04/08/99 | - | Added a new Patent listing in the Resources page. |
| 04/04/99 | - | Posted Corbyn's PI article from Wireless World. |
| 03/30/99 | - | Added a few more links. Especially check out Dan's Sidescan Sonar page, very interesting. |
| 03/24/99 | - | This Web page is officially up and running, much thanks to Christian Neumann! |
| 03/12/99 | - | Unofficial, preliminary preview. There is much to do... |
