Tektronix 577 Curve Tracer Repair and Demo

hello today we are going to talk a curve trades SiC Tronics 577 and I had it for a while but I finally need to get it going because I have run into transistor trouble in the restoration of another piece of equipment hey I like this one it says it belongs to engineering and like most of the stuff I get it doesn't quite work so I turn it on and this little dot which is good I put a diode in there but this doesn't do anything that I think I know what it is it feels loose oh I bet you the shaft is broken it might be a simple thing to repair so I love those Tektronix scopes they're me for maintenance and you can open them as a coin even just screw driver let's see what's in there yeah exactly so that's exactly what I thought would happen and it's a common ailment of these is that the coupling is broken here and might may be a very simple repair let's see if I can get it to work by turning this manually okay this danger high voltage brightness nice intensity okay so you have a little dot if you can't see it t as you can see they came out let me see I know to electrocute myself yeah that's all as long as it is a curve okay so I guess that's a not a very difficult repair so why am I not seeing all righty whoops like this okay I have to first figure out how to use it okay I just spent some time fits in with the buttons and finally after turning a few times back and forth it's a curved racer that's nice diode so that would be a simple repair and the hole by the way I'm not the first one to repair it the they had put a blade in here but I for his to stuff so it broke the other one so this is a beautiful repaired for Tahiti glued that part on so it's going to be pretty hard to remove it without breaking it No alright ok I have to break the plastic but it's dead anyhow and I'm thinking I might just use a piece of semi flexible tube in here that may be much easier I didn't have a clamps I just drilled right through okay that should work good enough this was nice machine to repair it I'll be right away a good transistor from a bad transistor yeah okay I guess the ducky a resistor once call - it's called a short-circuit apnea that's what it is for those who are not familiar with what a curve tracer is it's a basically a glorified IV tester Mix IV curves and this one is partly nicely made you have all kind of fixture to go on it you can test left or right and compare I have a whole collection here for example here on the right I'll put a holder and I'll just put a resistor so we're going to do an IV curve a resistor which is almost low and should give us a straight line so it's not that interesting but it's not cooperating with me here there we go so what you get is this is voltage and this is the intensity through the resistor and it's a straight line so of course you don't use it for resistors you use it for active components such as this diode and which gives much more interesting curves and no here you can see that in the front and positive voltage it conducts with a drop of a point two volts so it's a low voltage drop diode and it's an isolator on the other one on so it's a it's a nice rectifier one of the great feature of this instrument is that it can go to really high voltages and so let me crank it and 225 let's go to a hundred volts at which point this light illuminates tell me is getting dangerous and you have a key to defeat and the interlock are it wouldn't work and but so now I am going to try to look for the reverse breakdown voltage here and so I switched 20 volt per division and boom the diode turns on and now at minus 20 minus 60 and ha here's a breakdown of the diode so it's a really low turn on but the breakdown is actually fairly low 60 volts okay but let's switch to something even more interesting here let's put the transistor and here we go and for a transistor we are not in we are interested in the positive part of the curve so I'm going to drive it only positive so now with the transistor in it there is one more pin to attach the base so in regular mode you'll do anything to the base it just gives you the emitter collector current and when stop bias it's not conducting so here is the knob that controls the base current and if I start to raise it then I see the transistor starting to conduct and to saturate and of course what you do usually you don't raise it by hand and you want a family of curves so there is a nice integrated stepper here and that can raise the button for you and here it has two steps and then three four five six and more steps so here what you see is another nice feature of the curve tracer that it limits the participation of a transistor all by itself and this one is a power transistor so I can it's a 15 watt or more so I can go to 9 there you go and I see the whole series of curves of the transistor and so it gives you by how high that goes gives you the gain and it gives you the linearity or how high quality space and this is a very nice power transistor by the way and then also having an ability to go to high voltages is so let's put it to a hundred here and let's go to five hole per division okay ten volt per division and we're going to look for the breakdown of this transistor so it's a 40 volt and so it should happen yeah right right there loop there you go it happens at 50 no right on the money where it's predicted to so you get a pretty cool view of what your transistor is all in one shot so it's it's a nice and funny instrument to work with and this is the transistors I took out of the data i/o and which tested good at but hundred gain and it show that it's a very good transistor the way I'm set up here this is a 10 volt per division so this is a up to 80 volts right here to 90 volts so shows no sign of breakdown and this is what I thought was a bad transistor and it really is bad whoop ok so this is another transistor anymore and then I had a real high voltage transistor this one comes from a TV drive stage so it says 600 or 800 volt but you see the problem with these is that know they'll go forever in voltage but they trade that up finding almost no gain it's in the specs 810 and so it's just just nothing here you transistor but not good for what I want to lose it says it's a hundred volt transistor so that okay gain is exactly the same is not wipe the 100 volts 10 20 30 40 50 70 80 valid that's good because there is no more than 60 volt in a second so oh I think I can use it India as a replacement in the data i/o

Channel: CuriousMarc

Views: 20,085

Rating: 4.9644761 out of 5

Keywords: Tek, Tektronix, Test Equipment, Curve Tracer, 577, 576, Repair, Electronics, CuriousMarc, Vintage, Tutorial, Demo

Id: wXiR01HLhUA

Length: 11min 47sec (707 seconds)

Published: Mon Aug 29 2016