Just like VK5RC, I was inspired by people restauring old Tek scopes. Among them, Martin.M here. So thanks a lot to him and everyone for sharing their nice work and all the details!
*Moar glowy electronics* Hope you don't mind me sharing my story, and a few
*that's a lie* pics here in your thread... A year ago I got a 2465B which quickly became my main oscilloscope. It was in printine condition, and worked just fine. That was before I had any interest in vintage vacuum tube scopes. I was trying to build all the circuitry necessary to drive small CRT tubes, and also some nice stuff like scope clocks. I really needed an
awesome analog oscilloscope, and this was the one.
(All the pics are limited in size, and can be clicked to get the full size.)I opened it up the day I received it, and I noticed some electrolytic caps that were already replaced. The Dallas DS1225 memory was also replaced, so it seems like this unit is bullet proof for many years coming! I spotted some cracked, but not yet damaged, X2 caps in the PSU board though, which I did not replace right away. Maybe I should have... one of them blew up a few months later! No harm done, I replaced them all, thanks to another thread on EEVBlog with many details about this scope.
(There were a few others that I replaced too, this and these.)Apart from that, everything was so clean it could have been a brand new unit. So, this was not a restauration project.
More recently, last week, I finally got my very first vacuum tube oscilloscope, a Tektronix 310A, with the plastic handle and BNC connectors, compared to some others with a leather handle (that does not age really well, actually) and UHF connectors. I got this one on eBay US, imported all the way to Reunion Island (where I live). It was really dusty, that was to be expected. I won't go too much over the details about the cleaning process, but basically, the first thing I did was removing as much dust as I could using a vacuum cleaner and a soft paint brush. Then, I had to rewire the transformer for 234V operation.
(Fortunately, the silver solder spool was there at the back.)This scope was advertised as working, with a pic showing a trace on the CRT. So I replaced the fuse at the back with a 800mA slow blow, and I give it a shot. Success, it worked!
Time to get to the real cleaning now. I did not take any pics of before, this is the only one I have. It looks quite a bit dirty, but it was a lot worse inside.
(This was taken by the package forwarding company.)So, I took the unit apart, removed all the panels, the CRT and shield, all the parts of the frame that could be removed (except the panel where the AC outlet is, because I would have to desolder the fuse and mains connector). I also removed all the front and rear knobs. I washed all that using running water, soap, a plastic brush and an old toothbrush for the small parts. It tool multiple passes to get everything perfectly clean. I also used alcool for some panels and a paintbrush, but I had to be really careful with that, since it could easily remove the writings. I also removed the rear hinge which was matte and yellowish.
(This one was hard to clean, but here it is, nice and shiny!)Like I said before, the handle on the model I got, aged pretty well, unlike the leather one. I polished the supports on the sides.
(On the top right, I couldn't clean this since the adjustable caps are soldered in place...)Then I removed the tubes one by one, and cleaned them with water, and just my bare fingers, no brush or anything since it's not needed, and the writings were so easily removed. I cleaned some components inside, but it's not done yet. I'm not sure how to clean all the components, since there is not much room for a brush or anything. It will be fine for now, I'll see if I can do better a bit later.
(This side is almost completely cleaned up, except for the turret assemblies which I didn't touch at all.)(The other side. It's slightly better now, I did not take another pic though.)The inside, were not too dirty, I just used the vacuum cleaner again, and tried to wipe as much dust as I could with a brush. I can definately do better than that, but it's going to be tricky... One thing that needs to be done, is cleaning up the contacts of the turret switch that sets the Volts/Div. It's quite touchy and a bit hard to set right.
(I'd say it looks pretty clean on the pic.)So, that's about it. Now I need to calibrate it. That's going to be hard, since it seems like some pots are acting a bit strangely.
Everything else seems to work just fine. The CRT is terrificly precise! (Can't really see that on the pics, sadly.)
(Here it is, displaying the output of the calibrator. The right backlight bulb is dead.)Just a few more pics...
(This is it, after complete cleanup of the outside. I need the fourth graticule nut.)(Side view.)(Bottom view.)(And rear view. I really need a 234V tag, and two feet.)And to end this, some artistic pics of glowin' tubes.
There are some more full size pics, on
Flickr or
Dropbox.