Reg and all, I have finally attached the test report that I think Reg is referring too. Click on the link below. http://members.optusnet.com.au/~quarman1/Finders.doc In one of the paragraphs on page 3 of the report an interesting point (How Minelab test their detectors) is made and I have often asked myself the same question. On the Minelab SD-GP Mod forum, where I frequently post, I did pose a similar question but I changed my mind and deleted the post thinking I would not get an answer. However maybe with the large membership and visitors to this forum someone might know of Miinelab's methods used to test and compare before the release of a new model? GaryQ