Some time last fall I pulled my trusty 30 year old Textronix scope up onto the bench to take a look at it. It had been quite some time since I had used it and, since it had been sitting for quite awhile in our “less-than-climate-controlled” basement, I was apprehensive about what I might discover when I turned it on. After what seemed like a very long time, a very dim, fuzzy trace finally appeared. Exactly I had been afraid of, the long exposure to moisture had gotten into the HV section and some of the control voltages were “off”.
I pulled out the manual and, after some voltages and resistance checks, I located the most likely problem: a number of resistors with values much higher than specified…like by an order of magnitude more! I ordered some replacement parts and in a few days “Ol’ Tex” was again grinning his toothy oscilloscope grin as you can see in the photo.
Step 1: My Thought Process
I was very happy to have him back in working order and decided that he and I deserved to spend our retirement together in a place that was more conducive to “productive” electronics work. I negotiated with my wife to move into her former office on the 2nd floor of our house. So Ol’ Tex and I now have new digs…all warm and dry!
I slowly began moving some of my test equipment in only to discover that I really didn’t have enough bench space to give Ol’ Tex a good, permanent place to sit. As a result when he was in use, he had to sit on his backside pointed straight up. The overhead lights made reading the switch positions difficult and produced a considerable amount of glare on the screen. But most of all, I was not very comfortable with the fact that one of the cats might brush up against him causing him to topple over. With a newer scope’s flat LED screen this would not be much cause for concern, but I’m guessing that one good solid impact with the floor would be the end of Tex’s long necked glass cathode ray tube. And finally, I really didn’t have a good place to store him when not in use. So I came to the conclusion that I needed some kind of roll-around scope cart.
I’m not going to provide any sort of formal plans here because I am sure that everyone’s situation is different, but I think that anyone who looks at the photo will be able to adapt my overall design to fit their own scope. I mused about the requirements for quite some time before coming up with a relatively simple design that I could pull together out of materials that I already had on hand (basically (1/2" plywood, white glue and 1" long drywall style screws.
I wanted to make something that lowered Tex’s center of gravity and would angle him down a bit to reduce the glare and make the panel lettering a bit easier to read. While I was at it I figured that I could enclose the base with a low “wall” to make a convenient tray to hold probes, test leads, a meter and whatever else I might choose to put in there.
Step 2: Pulling It Together
By playing around I determined that by angling him down about 20 degrees from the vertical I would be able to accomplish all of the above and still make it possible to park the cart under the desk when it isn’t in use. I added a chunk of ¾” dowel rod across the front for a handle. I’m not so sure that was a real necessity because he can be moved around pretty easily without it.
I added a small “seat” out to the rear for Ol’ Tex to sit on…and a cleat on the side for coiling up the cord when he is in storage. I drilled a couple of holes in the panel at the top so that I could “park” the probes when I wasn’t using them (I’ve stepped on and broken waaaay to many of them not to want to treat them with respect!)
I purchased a chunk of webbed nylon belt and a buckle at a craft store and made a strap to keep Tex in place as I move the cart around.