In a message dated 25/01/00 18:37:12 GMT Standard Time, randallpratts@.............. writes: << I'm looking at the S-G construction notes on the PSN file. Does anyone have advice or experience with component substitution, operation on 12 volts instead of the 16 volts shown or other general comments? What about using the XTAL from a TV picture tube which I think is about 3.49 MHz? You need two L/C tuned circuits + diode rectifiers + smoothing capacitors for your two position sensor plates. These have to resonate with a stabilised amplitude crystal oscillator drive voltage on the central plate. The devices that Larry sells are already set up and tuned. If you don't have quite a bit experience of electronics (if you were completely confident of your abilities, would you ask?), buying the ready made sensor plates etc. would give you the certainty of success. The S-G circuit in my copy of the notes operates on +/- 12 V. The new design is a considerable advance on the original Scientific American circuit, which used 16 V supplies. Have you considered it? Regards Chris _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>