forgive any inaccuracies to those who may know better (or can remember better...)... what you will be interested in finding out is the deflection per inch voltage required for the beam deflection. I seem to remember ranges of 10-50 volts per inch. You will need to know the filament voltage of course and its amperage. What I don't recall is what the necessary acceleration element voltages were. The grid was used to control the beam brightness with a greater negative voltage with regards to the other elements dimming the beam (I think). The electrostatic plates should have the beam in center with zero volts and then deflection is accomplished by positive and negative voltages. If you can not find precise data then you can find the full deflection voltage by experiment once you have a center beam. I suspect that the long tube should give you a more sensitive tube in that the deflection voltage may be on the low end of the range. best regards, Steve Thatcher Original Message: ----------------- From: Tom Uban uban(a)ubanproductions.com Date: Wed, 21 Jan 2004 09:50:46 -0600 To: cctalk(a)classiccmp.org Subject: Advice on electrostatic deflection CRT ? Hello, I have what I believe is a custom CRT. It has a 12" round face, is approximately 20" long, and uses electrostatic deflection. It was manufactured by Thomas Electronics Inc. in Wayne NJ and is hand marked as model number 12E35P31, 12-2-78. I am hoping to put this CRT into service and need to come up with a set of specifications which will likely work with it. What other physical information do I need to take from the CRT in order to help determine the specifications? Any suggestions for creating the power supply and deflection drive electronics are welcome. Thanks! --tom -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ .