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The electronics chassis shown above is from a Precision Electronics Corporation (Landy Doyle) open hole gamma ray tool.  Ron Hattox at Armadillo Wireline Electronics, our good friend and one of the world's leading experts on open hole tools, indicates there are "only 2763 different variations and 1176 modifications" for these tools.  This particular tool had no high voltage regulator (we added one), and exhibited horrible drift with respect to detector stability.  The photomultiplier (PMT) used in this tool has a focus grid, a fairly unusual feature.  The original equipment PMT voltage divider was wired on the pins of the temporary base supplied with the PMT, and was so poorly executed it had to be replaced.  An interesting electronics design feature of this tool is the use of a 555 timer chip for pulse forming and line driving functions.  The turret terminal point to point wiring and the use of consumer grade capacitors are a bit of a surprise in a high-priced tool.

02-03-07
Last 10-20-10