Tektronix 575 Curve Tracer - Page 1
Forum section: electronics / testgear

author: JuiceKing
author_rank: Regular Contributor
timestamp: September 25, 2014, 10:44:43 pm
content: It lives!I had been looking for one of these for a long time, and finally found a nice one for not too much money on eBay few weeks ago. It was easy to clean up and needed just a little TLC inside and some new tubes in the power supply and horizontal amplifier to get it back into spec. What a magnificent beast.

author: Vgkid
author_rank: Super Contributor
timestamp: September 25, 2014, 10:53:34 pm
content: Nice, I was using one in school last year.

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: September 25, 2014, 10:54:34 pm
content: Not sure about its performance but I must say it is a beautiful retro piece of gear!

author: radhaz
author_rank: Regular Contributor
timestamp: September 25, 2014, 11:18:47 pm
content: Excellent looking piece.

author: nctnico
author_rank: Super Contributor
timestamp: September 25, 2014, 11:24:31 pm
content: That looks really neat & clean! Oh and I can't help noticing Christmas came early

author: bigsky
author_rank: Regular Contributor
timestamp: September 25, 2014, 11:35:35 pm
content: What an absolutely gorgeous piece of kit! It looks like it is brand new - bright, shiny, and clean - but I'd reckon it is 50 years old. Well done!

author: Martin.M
author_rank: Frequent Contributor
timestamp: September 29, 2014, 05:28:41 pm
content: Quote from: Alexei.Polkhanov on September 25, 2014, 10:54:34 pmIt can load the poor transistor with up to 200W power. One mistake on the buttons and it will be fried...The max. UC is for the regular model 200V, with option 122c up to 400V.This is a Classic Tek, nice, useful and with a very long lifemy 575 is the 400V Type.greetingsMartin

author: nctnico
author_rank: Super Contributor
timestamp: September 29, 2014, 05:41:03 pm
content: And yet I'm wondering why a transistor curve tracer is filled with tubes. The designers at Tektronix must be evil

author: Martin.M
author_rank: Frequent Contributor
timestamp: September 29, 2014, 06:08:21 pm
content: Tek 575 was build in the 60ts, this time the (germanium-) transistors was not good enough for the laboratory class.and - this Scope is over 50 years old and still working, means: never again we will get a quality like thatgreetingsMartin

author: SeanB
author_rank: Super Contributor
timestamp: September 29, 2014, 06:57:06 pm
content: I have Motorola data books from 1970, and the Germanium transistors were truly poor compared to the modern ones, most would struggle to get to 30V with leakage under 1mA, and the power devices were even worse, some proclaimed low leakage of 10mA. 400V was a dream, and only available in some then ultra expensive and exotic silicon devices, with horrid spread. Highest power device was a PNP 30v darlington transistor array, capable of handling 60A, with an impressive size, and even more impressive price. IIRC leakage at 30V was quoted as "Under 100mA". So, yes, to get good results and 400v you needed hot cathodes, and good design to make it stable.

author: Martin.M
author_rank: Frequent Contributor
timestamp: September 29, 2014, 08:04:51 pm
content: the little Tek below the 575 is a Sony-Tektronix Type323.Build from 1967, transistor .... up to 5mc. a trustful calibratet mini Tek.... it was a pay of more then 900$ that time.The transistors inside, when you look in the service manual, allover is to read "selected from..." and this was the way to build that.Using this fat 575 to select all of them575 have a brother 570 "characteristic curve tracer" to do the same with tubes..To see a very lot of hot kathodes use simply my homepage. I am collecting and restoring them, it`s my hobby.greetingsMartin

author: JuiceKing
author_rank: Regular Contributor
timestamp: September 29, 2014, 11:52:51 pm
content: Nice one, Martin. The 400V version is to "die" for!Over the weekend, I did some more testing of common modern transistors as well as neon and tungsten lamps. Some screen shots are here:https://www.flickr.com/photos/the-maestros/sets/72157647634831747/The few Germanium semiconductors I have are all tied up in working/potentially repairable gear, but I'll hunt for such exotica next time I go to the flea market.- Ken

author: Excavatoree
author_rank: Frequent Contributor
timestamp: September 30, 2014, 12:57:47 am
content: Nice examples, guys.Mine are bit crustier - but serve my purposes. I have a 575 and a spare, and the 577 that oddly doesn't get used as much as the 575.Now, I feel obsessed to find a 400V version. There will be no staircase full of curve tracers.

author: Excavatoree
author_rank: Frequent Contributor
timestamp: September 30, 2014, 01:00:34 am
content: My apologies - technically, mine are "crustier" then these fine examples, but that does seem to imply that those are "crusty," which is not the case. I should have said those are pristine, mine are a bit crusty.

author: lowimpedance
author_rank: Super Contributor
timestamp: September 30, 2014, 01:05:35 am
content: Just love that glow, nice vintage kit. I assume it also has that vintage smell when 'glowing' !.

author: SeanB
author_rank: Super Contributor
timestamp: September 30, 2014, 06:39:33 pm
content: Quote from: JuiceKing on September 29, 2014, 11:52:51 pmI have some NOS germanium transistors if you PM me with a postal address to send them to you. Might be a while though as SAPO is still on strike, so mail is very slow, even for South Africa.

author: Martin.M
author_rank: Frequent Contributor
timestamp: September 30, 2014, 06:51:16 pm
content: Quote from: JuiceKing on September 29, 2014, 11:52:51 pmhello Ken,the complete Tek Show is another:Put the 575 on a scope cart 500/53 and on the ground stage the hughe 175 Extension to provide0 - 20 V collector voltage, 200 A maximum collector current0 - 100 V collector voltage, 40 A maximum collector currentSo the oldie can destroy all kind of Transistors and rectifiers, including the very large typesThis set is one of the most powerful ever made by Tek.greetingsMartin

author: xwarp
author_rank: Frequent Contributor
timestamp: November 29, 2014, 10:19:22 pm
content: Quote from: JuiceKing on September 25, 2014, 10:44:43 pmWould you mind posting the set up and trnasistor part number you tested?I just received one of these 575's and it has some issues that need looking at.I've already replaced a couple of 6al5's and 6au6's.Thanks!

author: JuiceKing
author_rank: Regular Contributor
timestamp: November 30, 2014, 12:09:44 am
content: Quote from: xwarp on November 29, 2014, 10:19:22 pmClick on the trace pictures to go to the original in Flickr. I have a bunch in a collection there, each with the name of the part under test and the set up parameters in the comments under the image.Good luck!- Ken

author: JuiceKing
author_rank: Regular Contributor
timestamp: January 09, 2015, 06:52:20 pm
content: Quote from: SeanB on September 30, 2014, 06:39:33 pmSeanB very kindly did send me those germanium transistors and diodes from South Africa, and they arrived here in Massachusetts this week!I started with one, unmarked power transistor that looked inviting. Through trial and error I determined that that it is NPN and identified the terminals. I compared it with a modern silicon power transistor.Results are here:Power NPN (Unmarked Germanium)byKen Schwarz, on FlickrClick on the image to look at the series of comparative shots. You can see that the beta of this Germanium transistor is higher, with similar linearity at higher collector voltages, but a smaller saturation region. With this nice Germanium transistor, I was cautious with the power and didn't explore thermal runaway conditions.Many thanks again, Sean!- Ken

author: SeanB
author_rank: Super Contributor
timestamp: January 09, 2015, 07:04:20 pm
content: Some were silicon transistors, I did find a board with old Ge transistors, I will have to cut some out for you, came out of an old Compet calculator.

author: JuiceKing
author_rank: Regular Contributor
timestamp: February 07, 2015, 05:49:14 pm
content: Quote from: SeanB on January 09, 2015, 07:04:20 pmI did some more testing. It turns out these ones I traced were silicon BJTs after all.- Ken