Hello World,
At last I managed to grab a 575 curve tracer. Wanted one so badly ever since I started getting into old glowing Tek scopes, 4 years ago or something. However too rare (one pops up every year or two) and way too pricey for me (500 Euros usually...). But what do you know, this one popped up at only 100 Euros ! As always good deals disappears within minutes literally, and since I saw this one 3 hours after the ad went on-line, I was toast... but tried my luck anyway, immediately offering 50% more to the seller, 150 Euros... he phoned me saying I was the highest "bidder", and the deal was done ! Next day he had another old guy happy to offer him 500 to steal it from me, but luckily the seller was honest enough to refuse the offer, and sticked with me, phew that was close !
Spent another 150 in petrol and tolls as the thing was 450kms away from me ! But either you are motivated or you aren't !
At 300 Euros once back home, it's still well worth it. And I can just pretend I was nearby to visit some friend or family or whatever... so as far as I am concerned it cost me only 150
Anyway, so happy to have a 575, I am over the moon. Definitely the master piece in my collection of glowing Tek boat anchors.
Not only was it cheap, but it also comes with many hours of fun to restore it !
Indeed this poor 575 is in need of an incredible amount of TLC... so many things wrong with it.
However it basically "works" and there are no show stoppers, blown transformer or defective CRT... nothing of the sort, which is the most important !
I guess I could keep it for parts and look for another one in better condition, but they are too rare and expensive that I might as well wait for years and pay 500 for the next unit... nope.
So it time wise, or financially-wise... it's much cheaper and faster to just try to resurrect this one.
I am no magician so it will never be in concourse condition, but neither is my goal so that's fine.
Goal is to make it perfect electrically, make it a usable instrument, calibrated, accurate, as it should, and tackle the numerous mechanical and cosmetic issues as best I can. However I intend to take all my time and do the best job possible.
It's the basic 200 Volts version not the 400V one, but hey you can't have it all. That doesn't keep me from loving it to bits.
I have powered it up for an entire day, playing with it extensively, and discovered en route its numerous problems.
So I am creating this thread now, so as to log all the problems that need to be addressed, while I still remember them.. but probably won't have time to restore it immediately as so many other priorities currently, but I am really eager to start on it so am hoping it will see some action in the coming months.
Due to the varied nature of the problems that need fixing, and the sheer amount of them... what I am thinking is that the restoration will not be linear. I will probably look for the low hanging fruits first, that require little disassemby of the unit, as well as fixing the electrical side of things, then only move on to the nuts and bolt restoration to tackle the cosmetic side of things. Something like that...
Anyway, so let's list all its problems now.
E X T E R I O R- Rusty screws all over, and on the metal work on the cabinet panel, carry handles.
- Carry handles need refreshing, looking sad as they always do. Looks leather buy looking more closely at the back of the leather... I am not so sure ! Looks like fake leather fabric, I don't know... Tek did make real leather handles (have some on my Type 317 scopes). Regardless, think I might redo them in real leather, possibly in black (type 317 had them black) rather then blue.
- RHS panel, top side, toward the front. The entire area between the front edge and the front of the little compartment that hold the owners booklet, is caved in. Doesn't show well on pictures, but it is...
- [ FIXED ] Door for aforementioned compartment: it is jammed closed. Only way to open it is to pry it 
Problem I think is that it's misaligned, it's crooked. One edge of the door is hitting the panel. Don't know why just now. Given the panel is caved in in this area, I guess the instrument took a big hit that might have distorted the hinge for the door. Anyway, it needs some metal work to straighten things out...- [ FIXED ] - Bottom right corner of the test panel (where you shove the transistor under test) is bent outwards, corner is sticking out, also causing the binding post present here, to be misaligned wrt to its two brothers above him. Panel seems to be soft aluminium so should not be too difficult to straighten.- CRT bezel: bottom right stud is missing. This is one is no quick fix as it requires to take the entire face plate off !
So this will be done towards the end of the process, when I do the nuts and bolt restoration.
- [ FIXED ] - Knobs: the one used for the " Series Resistor " setting, in the "Base Step Generator " section of the front panel... is not the correct one ! Basic shape/ style is correct, but the colour is wrong, it's dark grey instead of black. Also it has a hole in the center as if it was meant to carry a secondary red know atop of it.- " Steps / Sec " Toggle switch: its bat is bent, along two axis. Nothing dramatic but one you know about it it bothers you no end !
Not sure how feasible ti is to straighten it... too tiny to grad it firmly I think. Might be easier to just replace it, if I can find one somewhere...
- Corrosion and crustiness on and around and under all the washers and locking nuts for all the toggle switches and push-buttons. Looks horrible.
I N T E R I O R- [ FIXED ] - Chassis, top, right side : missing the long stiffener/beam that runs from the front to the back of the instrument.- [ FIXED ] - Chassis, left side, between back panel and lower deck : missing one of the three screws that secure the triangular stiffener.- Chassis, left side, lower deck: missing a large panel with lots of printing on it, that covers the area where the rectifiers and collector voltage power stuff is located. Including a picture taken fro Tekwiki that show what this panel looked like... hoping I reproduce this panel.
- [ FIXED ] - CRT: its neck is completely lose, the mechanism that's responsible for rotating the CRT / neck is in bits. Looking at the exploded views in the service manual, I am missing the piece that grabs the neck. Well apparently it may not be "missing" but "only" disintegrated. Apparently it's a know / recurrent problem on these old Tek machines. This part was made of some rubbery lie material that disintegrates over time. As a result the neck is lose and it is therefore impossible to orientate the CRT properly. Luckily it seems like standard part common to all 500 scopes, not just the curve tracer, so I should be able to pinch this part from one of my 500 scopes. If not, I gather someone in Germany makes these parts, so I should be covered...- Upper deck, center line, rear. There is a vertical piece of aluminium where a couple Germanium power trannies are mounted, kinda serves as a heatsink. There a few rubber grommets running through that heatsink. They look bad and some are missing. Well, the split in two and both halves migrated down the wire. They look kinda generic so hoping one can still buy them new today.
- These two Germanium transistors look rather crusty... hoping the oxidation has not migrated inside the case... however did a quick search and believe it or not these ancient trannies are still available, not new of course, but old stock.
- Cooling fan : slow to start and a bit noisy. Needs lubricating of course but from similar experience on my type 317, the slow start maybe caused by something more subtle that's not as obvious... I still have not managed to fi xthe slow start issue on this bloody 317 !
E L E C T R I C A L- Wafer switch, setting range for collector voltage (either 0-20V or 0 to 200V). Huge damage to the outer most wafer, as obviously that's the most accessible. Luckily it broke " cleanly ", just one big chunk, not small debris. Also the broken part is still with us as it is held in the vicinity by wires that were soldered to it, phew.
- Toggle switch : " Mode " switch for the Base Step Generator. Has 3 positions : OFF, " Single " and " Repetitive ". The latter is what you want 99,999% of the time. Sadly if you flip the switch to this position, it won't stay there, doesn't lock into place, the bat immediately falls back down to the " OFF " position. The tip (in contact with the bat) of the corresponding moving contact in the switch, is broken, metal fatigue. In the pictures below you can see the tip of the contact massively bent, begging for life. Hanging in there with just a few iron atoms... I barely touched it and it snapped right off. I kept the broken bit just in case I manage to solder it back into place, or to use as a template to replace this contact using another contact from god knows what apparatus. An old beefy relay of some kind. I think it's not a lost cause, but still not a quick and easy fix.
- Power socket : the instrument still has its original USA style socket. However a modern European power cord was also fitted, for convenience. Problem is, guy who did it did very poor job, a dangerous one even. He soldered the wires from the cord, straight to the terminals at the back of the original socket... the quality of the solder joints leave a lot to be desired ! Also, the insulation of the blue wire has a big cut in it, exposed copper ! And to top it all... guy didn't seem to believe it was worth connecting the earth wire at all !
So all that needs redoing properly. Might get rid of the cord, remove the USA socket and replace it with a modern IEC socket, as it's more practical. I hate instruments with hardwired power cords (or whatever cord at the back of the unit), they drive me nuts.
- [ FIXED ] - Now on to actually testing the operation of the 575, with a transistor plugged in. I can display a set of curves, however they look weird. Other than the obvious orientation problem because of the loose CRT, what bothers me is the lack of vertical line on the left, joining all the curves... i.e. the linear region of the transistors. It's just not there at all ?! 
All I see are the horizontal / saturated parts of the curves. On their left all I see are curled wiggly lines connecting the left edge of each curve together ?! Definitely not right..OK I think that's about it as far as problems go. Did it from the top of my head but I think it's a complete list... well of course I may well discover more problems later on, as I work on it... but that's all I noticed in this "first pass" so to speak.
Now for the pics illustrating all that, hopefully in a similar order to the text, to make it easier to follow...
Home
Help
Search
Login
Register
