Fred, Thanks. I will look for that transistor if I get in. I appreciate the advice.
John -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Fred Townsend Sent: Thursday, September 25, 2008 3:49 PM To: Repeater-Builder@yahoogroups.com Cc: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Off Topic -- Tektronix 475 Oscilloscope John I will let others tell you how to get the scope out of the case. What I will tell you about is a defect in the early model 465 and 475 power supplies. After you check out the fuses and normal power checks you will want to check for a shorted transistor. In the scope's internal power supply is a TO3 transistor with a Tek part number on it. The manual says it's a custom part, hence the special part number. You may be able to order the transistor from Tek but their part may fail again. The permanent fix is to replace the transistor with a steel case 2N3055. I used a RCA part but I'm not sure they are available. It is very important not use a Motorola (Onsemi) or any other aluminum case part. 73 de AE6QL, Fred townsend
