Re: [Repeater-Builder] Off Topic -- Tektronix 475 Oscilloscope
Usually you remove the back panel, i.e. the rubber feet and cover on the back end of the unit. There may be additional screws under that, holding the outer cover to the chassis. They'd probably be near the corners. Then the outer skin should slide backwards, leaving you with the guts coming out the front. On the larger scopes, the outer skin had a left and right half. You should be able to find some photos of the inside of the unit. Perhaps one will include the outer cover partially removed. Of course, this is very general and your mileage may vary. Bob M. == --- On Thu, 9/25/08, John Transue [EMAIL PROTECTED] wrote: From: John Transue [EMAIL PROTECTED] Subject: [Repeater-Builder] Off Topic -- Tektronix 475 Oscilloscope To: Repeater-Builder@yahoogroups.com Date: Thursday, September 25, 2008, 2:56 PM Can anyone tell me how to get this oscilloscope out of the case? When I unplugged it from one outlet and plugged it into another, it apparently became shorted someplace beyond the fuse. The fuse blew, and a replacement blew. I suspect a short in the power supply, and I would like to find and fix it. I removed the back trim. Should the front face and innards slide forward out of the case? Any help would be greatly appreciated. Thanks. John Transue AF4PD
RE: [Repeater-Builder] Off Topic -- Tektronix 475 Oscilloscope
This link may be better info http://bama.edebris.com/manuals/tek/475 Rob - KS4EC From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of John Transue Sent: Thursday, September 25, 2008 2:57 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Off Topic -- Tektronix 475 Oscilloscope Can anyone tell me how to get this oscilloscope out of the case? When I unplugged it from one outlet and plugged it into another, it apparently became shorted someplace beyond the fuse. The fuse blew, and a replacement blew. I suspect a short in the power supply, and I would like to find and fix it. I removed the back trim. Should the front face and innards slide forward out of the case? Any help would be greatly appreciated. Thanks. John Transue AF4PD Since 1974, the award-winning Alpert JFCS has helped families of all faiths throughout most of Palm Beach County, FL, via counseling, seniors services, residences for the disabled, mentoring children, support groups and a lot more. SOLUTIONS FOR LIVING www.JFCSonline.com Please take note of our new website and E-Mail Addresses. Please update your contacts ASAP. NOTICE: This e-mail message and all attachments transmitted with it are intended solely for the use of the addressee and may contain legally privileged and confidential information. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, copying, or other use of this message or its attachments is strictly prohibited. If you have received this message in error, please notify the sender immediately by replying to this message and please delete it from your computer. image001.jpgimage002.jpg
RE: [Repeater-Builder] Off Topic -- Tektronix 475 Oscilloscope
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
