Look Inside This Rare Tektronix TU-50 Test Unit!

hi everyone and welcome to another episode of mr. Carlson's lab today we're going to take a look inside a very interesting piece of equipment a very rare alignment device for these things so the instrument that we're going to take a look inside of was used at Tektronix to align these when they were brand-new off the factory line very neat piece of equipment to own so let's take a look inside this thing and see what's in it here we are in lab number two and what you see is just some of the projects that are coming up so this is the old-time workbench and on the old-time workbench is a very large type 50 tu test unit right in front of us and that's what is used to align the 500 series oscilloscopes and other scopes as well so we are going to use this piece of gear right here to do alignments on scopes like all of these right here so that should be a lot of fun so lots of projects as you can see coming up so what I'll do is I'll get a little closer to the type 50 tu test unit take a look at it and then we'll take a look inside and see what they're hiding inside this really heavy piece of gear that's fan cooled and has air filters on both sides here's a closer look at the face of the type 50 tu test unit and as you can see it has different blocks for testing different portions of the oscilloscope and these blocks can be selected by that selector knob there you can see one arrow points to this block another to this block here and another to this block here now one thing that's really important to have with this is the attenuator probe and that is this piece right here so we'll take a look at this and inside this right at the end here so we'll take take this all apart and look inside and see what's in there I believe there is a tube in here so it has power to this and everything so this plugs into this right here like so and then just give this a twist and it locks this into place and then this here would go to the oscilloscope vertical input and then this is the volts peak-to-peak attenuator here so you can set it to all the different ranges so nice piece to have it's very lucky to get this attenuator with this because a lot of these things they're separated and throughout time these things go missing very important piece to have with this so when we go through and restore this thing and align it I really don't think there's a whole lot to do restoration wise with this thing most likely going to be an alignment maybe changing of a few parts probably classified more as a repair if anything so go through it and make sure that it's working and then calibrate this so we can use this and we can calibrate some larger oscilloscopes together so it's one thing to be able to use an oscilloscope it's another thing to know as much about an oscilloscope to be able to calibrate it and I'm going to show you guys all of this here in the near future so as you can see here we have an amplitude calibrator so this is calibrates the amplitude here for this one section and we have a sine wave output it puts out 50 kilocycles five mega cycles 10 15 20 25 and 30 mega cycles to calibrate these oscilloscopes we have a square wave generator up here so we can generate square waves from 10 to 100 cycles 100 to 1000 cycles 1 to 10 kilo cycles or 10 kilohertz if you like modern speak that would be killer Hertz so whenever you see kilocycles if you're not familiar with cycles just change it to Hertz so kilohertz 50 to 500 kilohertz and 50 to 500 kilohertz here and this is a fast rise output so this is a very fast rise so basically the same thing but just very fast rise here again we can adjust the amplitude right here and vary the frequency now this is a very important part of this right here the time mark generator what that allows us to do is calibrate the horizontal time base and make it read correct to the graticule on the oscilloscope so we have all these switches and we can combine them it's not only one we can put one or two together at the same time but if we wanted to calibrate the screen for one microsecond we turn that on and we would have markers on the screen for one microsecond and it's the same thing for if we wanted to go as low as five seconds which in most well in a lot of my oscilloscopes is in roll mode so you click it on to five and then every five seconds you would get a mark so that's the way it goes so we have markers here and we also have a signal selector for five ten and fifty megacycles output so megahertz so to be fifty megahertz output right here and we also have a trigger it helps with the very slow signals as well so lots of stuff to align and check out on this thing when we actually go through it make sure everything is working properly with modern equipment aligning something like this is actually very straightforward and usually tech is very good they mark everything inside so it just makes it all that much easier to online a lot of pieces of test equipment they'll have VRS and coils and everything all over the place but nothing's marked so you have to have a manual this is just you can look at it and go okay you know this is the the alignment for this section here or a marker alignment and you can trim everything up it's very very nice that's usually the way Tech went you know with all their oscilloscopes as well everything was marked inside so very nice and any type of servicing that needed to be done in the field could very easily be done by a technician because you can take the case apart on the unit you know lift it up off and go okay this is out of alignment I need to adjust you know the 150 volt source or something like that you know you line it in the way it goes again right again you know like this stuff back in the day was absolute top-notch absolute top-notch and so what I'm gonna do now is turn this thing around actually what I'll do is I'll show you the air filters on the side so there's one here this here is the intake filter so it draws air in this way and then on the other side outch is the output that's heavy this is the output right here so it blows air out this way and draws it through the case to keep all the vacuum tubes cool and there are a lot of vacuum tubes in this unit so what I'll do is I'll turn this thing around get the cord off the top here even came with the special cord with the angle to plug on it so get this off the top turn the thing around remove this and we'll take a look inside and see what kind of tubes we have going on and how they've laid this thing out in order to get inside the unit it's really quite easy I just have to give this fastener a twist and that one a twist I don't need to completely remove them just give them a twist like this and like so and then put my hands on the top and then pull towards myself and the whole case comes off like that and there are a lot of tubes up here so what I'll do is I'll just open this up and I'll bring the camera in a little closer and we'll take a look around all right let's take a look around so here we go look at all the tubes in there that is a lot of tubes you can see why this thing definitely needs to be fan cooled so it pulls air in from this side over here and the fan exhausts on this side here lots of tubes there five selenium rectifiers and if I can leave those in I'm going to leave those in supposedly this unit does work so there is looks to be some form of a oil splatter or something on the chassis I really don't know what that is and it's all over the place it might just be dirt maybe at some time the filter was oiled or something and it was pulled through because I can see it all over the chassis so it's not just concentrated in one area so it's not like a component exploded or something like that it's probably just drawn off of an oil derrick cleaner somebody probably did something at some time in the past with this thing so this would be the regulation section down here and on the top this is the time mark generator and there's a lot of adjustments on the upper side of this well take a look at that in a moment I'll show you all the adjustments to make sure that the time mark generator is okay you see down here is an oscillator and these are all the adjustments for the oscillator 64 oscillator tube their regulator tube in the back and more tubes hiding back in there and some tubes up in here as well they a sea of tubes up here lots and lots of vacuum tubes there so all-in-all this looks like it's in very nice condition you know it's very clean inside so somebody has taken good care of this thing of course you know routine maintenance would mean spring switches with a cleaner and cleaning them out moving them around and things like that and hopefully you know the tubes are okay too as well cuz that is important so and there are a lot of them here I couldn't imagine re tubing this with brand new vacuum tubes that would be a very expensive thing to do if you have to replace all of these tubes and everything in here so what I'm going to do is I'm going to move the camera and I'll look at the top side of this and I'll show you all the adjustments that are made and you can take a look at the components and how tech put this together on the ceramic strips it's a really nice design here's a look at the top side of the unit and as you can see right in the time mark generator they have all the adjustments mark to make the alignment nice and easy you can see the really nice construction with these ceramic strips now whenever you're working on anything like this they suggest that you use solder that has a silver content in it if not it can cause problems with migration and it can damage these ceramics strips so the little portions that the resistors are soldered into can actually come out of the ceramics strip so that's a very important thing to remember whenever servicing anything like this you can see that they've used these Spragg capacitors that have the red writing on them and that means that these are a die film type capacitor and these are fine they don't exhibit very much leakage at all so no problems there as you can see very nicely laid out all over the place it's just you know the quality that's put into these things is really quite incredible now these goodall type capacitors I'm not sure Goodall makes all sorts of different types of capacitors and I'm not sure if these are going to be leaky or not and that's one thing that I'm going to want to check in fact why don't we do that now what I'll do is I'll turn on the soldering iron and I'll remove this one here and we'll just check it and see if it's leaky I'm kind of thinking that it's probably going to be good but I've had good all capacitors that do leak in the past so be interesting just to check that out right now and find out okay what I'm gonna do is D solder this end of this goodall capacitor so that I can test this for electrical leakage so this end of the capacitor is attached to this wafer switch and this is just an easy spot to get to I don't need to desalter this end I can leave this end in circuit and just use my capacitor tester to test this just the way it is and I'll show you how that work here in just a moment so I'll grab my desoldering tool and these are getting pretty tight just about doesn't reach okay this is gonna get noisy in a moment so I'll warn you okay I'm warning you all right I'll grab my leakage tester here and place this in here just like so hopefully that'll stay you can see that okay all right and I will attach these leads untangled over here I'll attach this leads to this end here and I'll attach the sense lead to the open lead that's how that has to be the sense lead can never be attached to anything that's attached in circuit it always has to be at the lead that's open and I want to make sure that the sense lead the boot isn't touching anything in circuit because this tester is so incredibly sensitive that it will read the leakage of this vinyl boot in fact that's part of the alignment procedure for this one this thing is built okay so what I'll do is I'll put this onto the discharge position right now this is in the poly and paper and foil position so when I click this on to test what'll happen is this will go red and this should count down and this should turn green again if it does that this capacitor has low leakage and then I'll give it one further test which is called a forecast test and the forecast is an extremely sensitive leakage test so that's used for testing mica capacitors and the like and if it's fine in the forecast test then this capacitor is definitely good to go so I'll test this here so it should go red and count down I count it down very fast so now if I click this into the forecast test and this doesn't count back up it should be fine give it a moment and that's looking really good so now I'm going to do is I'm going to discharge the capacitor and I'm going to actually test this capacitor in the forecast setting so again the forecast setting is extremely sensitive and it's really intended for mica capacitors and capacitors that have extremely low leakage like the ones that I have verified and I've put an entire list up on patron about you know I've spent countless amount of hours testing different components and I've put lists up there and any read so this is in the forecast setting right now so what I'll do is I'll click this on to test and if this counts down I know this capacitor is extremely good oh yeah this capacitor is really really good so that's good to know so chances are what I'm going to do just to be absolutely sure before I go about rebuilding here going through and repairing this because really I don't think there's much of a rebuild with this as I go through this thing what I'm going to do is all remove one more of these good ol capacitors and verify it and if it's the same as this one chances are they're all going to be good again this thing tests for electrical leakage so this is looking for any trace amounts extremely small amounts of leakage resistance inside this capacitor and as you can see it's virtually nothing so if you're interested in building one of these things all the plans all the schematics component layout maps that printed circuit board layouts everything is all available on patreon so you can build one of these things yourself very good addition to any bench excellent tool I'll use this thing all the time as you can see so what I'll do now is I'll disconnect this and solder this back into the circuit again and then let's take this attenuator into lab number one and open this up I want to see what's inside this thing let's take a look inside the attenuator the plug itself is made by Canon and as you can see the signal would obviously go through number four and then there's three extra pins and you see that there so the attenuator needs power so there's obviously a device inside this attenuator that requires that so in order to get in here it looks like we're gonna have to remove these four screws and remove this knob so we can see that there is a somewhat of a set screw in there so what we want to do is turn that till it's facing this way because this is basically the shortest way in and I'll grab my favorite tool here this thing has been amazing whenever I need some form of a hex key or allen wrench whatever you want to call it seems like this thing always works and it's like perfect every time great little tool to have them around and out of there and there we go a lot of the times when you tighten the setscrew in these things that scores the shaft a little bit then they bind when you take them off so what we'll do next is remove this because I imagine this is probably gonna be somehow fastened to this end because there's a connector here right this looks like a PL 2:59 or something yep PL s o s o 239 PL 259 type of connector this is a barrel connector here and with a BNC adapter on it so a BNC cable can be used so it just fits on there just leave that on so we'll do is I'll just remove this take this off of here everything is on incredibly tight and uh there there it is okay so try and remove these screws though it's scoring up the face gotta love these slot headed screws let's do this here I really like you know Phillips or a Robertson or even torques is nice this is a lot less chance of slipping lots of jokes go around to both these slot headed screws so let's see get this there it is take a look inside ya little tube down in there it's a cute looking little tube gold lettering on it looks like it's been glued into place feels like silicone and those are the resistors on the attenuator there so obviously this would use a good contact cleaning clean it all out and I imagine it would be forget that point this is very solid in here so there's something running directly into this connector down here so chances are getting this entire unit out and then of course with this cable because the cable kind of comes in here and there's no relief would be a real big pain so I'll just take a look at it through the top through the coax comes in I believe the B version of this had diodes in it so that is obviously a vacuum tube that has two diodes in it you can kind of see through the glass they kind of resemble a six al-5 very close very neat so what's inside the attenuator so very soon we'll go through this thing see how in alignment the actual t-50 is and then if the thought of alignment we'll perform an alignment on it and bring the thing back to where it should be so that we can align some 500 series oscilloscopes should be a lot of fun if you're enjoying these videos you can let me know by giving me a big thumbs up then hang around there'll be many more videos like this coming in the near future we'll be taking a look at vacuum tube and solid-state electronic devices alike lab number two is absolutely full of very interesting and rare pieces of equipment that we're gonna take a look at very quickly and then down the road we're gonna restore these pieces of equipment together so it should be a lot of fun so if you haven't subscribed now would be a good time to do that and if you want to be notified as soon as I post a new video don't forget to tap that Bell symbol if you're interested in taking our electronics knowledge to the next level and learning electronics in a very different and effective way and gaining access to another ninety videos and in those ninety videos are a lot of projects that you can take part in a lot of things that you can build I'm also sharing many of my designs and inventions up there as well so definitely check out patreon if you're interested in this sort of thing I'll put the link just below the video's description under the show more tab and I'll also pin the link right at the top of the comment section so click on the link and it'll take you right there so until next time take care bye for now you

Channel: Mr Carlson's Lab

Views: 54,953

Rating: 4.970665 out of 5

Keywords: Oscilloscope, oscilloscope repair, oscilloscope restoration, test equipment, repair electronics, fix electronics, restoration, restore electronics, learn electronics, radio repair, radio restoration, fix radios, test equipment repair, electronics, Tektronix Type 50TU Test Unit

Id: QVysOwtV5xc

Length: 22min 23sec (1343 seconds)

Published: Mon Mar 30 2020