Tektronix 576 Curve Tracer Adapters

[NF6X]

I just bought a Tektronix 576 curve tracer on eBay, and I'm picking it up tomorrow. I'm gambling that it will be repairable; the listing shows it producing a trace on the CRT, so it's not entirely dead at least. Purchase price was negotiated down to $600, and it's within pick-up distance from me. The readouts are dark in the photos, but the readout intensity knob appears to be turned all the way down. Nothing appears obviously missing in the photos, though the offset mult counter knob looks a bit out of whack. Please wish me luck with it! As long as it doesn't have any fatal flaws like a burned out transformer, I think I'll be satisfied with it.

I'm browsing eBay for a basic set of test adapters for it, and there's one thing that is confusing me: Are there any electrical differences between the various dual-width transistor and FET adapters such as A1007, A1009, 013-0098-02, and 013-0099-02? Or do they simply have different markings on the top? Can I just get one of any of them and then add some tape markings if it isn't marked for both FETs and BJTs?

The machine includes the standard test fixture, but is missing the 337-1194-02 safety cover. I wonder if I might find a nice way to fabricate a replacement? I'd rather use the safety cover than bypass the interlock.

[perdrix]

The Annnn adapters were designed for the 370 series curve tracers - they do work with the 576 though.

You need to read the datasheets - the 013-0098-nn and 013-0099-nn are wired differently.

You can find those datasheets at the Tektronix wiki - e.g. https://w140.com/tekwiki/wiki/013-0099-00

HtH
David

[NF6X]

Thank you! The 013-0098-nn seem a lot less common than the 013-0099-nn.

[Stray Electron]

  Adapters for the Tek curve tracers are like GOLD on E-bay! 

   Give us an update on your CT after you check it out!

[NF6X]

Yeah, I've noticed! I may have spent as much on adapters as on the instrument itself, even with offers below asking price. I'm just putting my hand over my eyes and not adding the numbers together. So far I've ordered one axial diode adapter, one TO-220 and friends adapter, one TO-66, one combination TO-3/TO-66, and I think I have an offer on a TO-3. It's been a blur.

Uh, regarding the adapter datasheets for the 013-0098-nn and 013-0099-nn: I see that they have different PCB part numbers inside, but I don't see details of the wiring differences. I'll need to keep digging through the manual scans to see what I can learn. I see a number of the 99 adapters listed now, and I'm waiting to see if an offer gets accepted before I grab one. I don't think I see any 98 adapters at the moment.

Are the 202 series scope carts about the right size for the 576? That's what I infer from looking at tray dimensions on the Tek Wiki.

Edit: Aaaaaand my offer on a NOS "99" FETs adapter was accepted. I really don't want to add up all of the individual purchases. I guess I still need to find a "98" FET/BJT adapter.

[Stray Electron]

  Now you see why I paid over $1000 for my Tek 576.  It included a pile of adapters and they would have cost more than that to buy them individually.

   I hope your 576 doesn't have any broken knobs or you're going to be in for another surprise!

[NF6X]

Oh, it has some cracked knobs, and the left/right switch looks a bit bent. I have a replacement switch and a whole standard fixture sitting in my watch list in case I need them! For the knobs, I might bling it out with billet aluminum knobs turned on the lathe at work rather than replacing the originals... that would probably be cheaper! It's not as bad in the knob department as some listings I've seen. My biggest concern so far is the wonky looking div mult knob.

Oh, yeah, I guess I might as well link to the listing. I hope nobody looks at the photos and gives me any especially bad news!

https://www.ebay.com/itm/374466324163

[mawyatt]

Here's a link to various type adapters, we are delinquent in getting ours done

https://www.eevblog.com/forum/projects/smd-test-fixture-for-the-tektronix-576-curve-tracer/msg4553639/#msg4553639

Best,

[NF6X]

I saw that thread earlier today! It is inspirational. I take it for granted that I will make my own adapters eventually. I'm also interested in trying some tube (AKA valve) tracing.

[Stray Electron]

Oh, yeah, I guess I might as well link to the listing. I hope nobody looks at the photos and gives me any especially bad news!

https://www.ebay.com/itm/374466324163

   That one looks pretty good! It's probably the best looking one that I've seen on Ebay in several years.

    I had looked at some CTs that they sold in the past but I'm on the other side of the country and was afraid of what the shipping would cost.

[NF6X]

Oooh! You are filling me with hope!

[mawyatt]

I saw that thread earlier today! It is inspirational. I take it for granted that I will make my own adapters eventually. I'm also interested in trying some tube (AKA valve) tracing.

Here's what we've done in the meantime which has "delayed" finishing the Tek 577 adapter fixture. This allowed us to "get what we needed done" with the 577 with the DIY Large Gator Clips and Small Clips shown.

The larger Gator clips were made by soldering a Banana post from a male Banana plug to a large Gator clip, the smaller clips were small clips, wires and Banana plugs. This was stuff we already had, so quickly solved our adapter/fixture problem at the time.

Best,

[NF6X]

Very nice! Simple and functional. 

[David Aurora]

Welcome to the club 

I've only got one official adapter (the BJT one mentioned), otherwise I've either been using short banana to alligator leads or connecting to external test jigs I made up with banana cables. Prices on used jigs are just stupid with shipping to Australia on top.

That said, I just got a handful of these boards made up and they arrived earlier today. The plan is to always have some of these base boards pre-wired so any time I need a different jig I just make a board with whatever sockets are required, connect it to one of these and stick it in a box.

[NF6X]

Nice idea. I like it. Maybe I'll do something like that, too?

[David Aurora]

Here's a link to various type adapters, we are delinquent in getting ours done

https://www.eevblog.com/forum/projects/smd-test-fixture-for-the-tektronix-576-curve-tracer/msg4553639/#msg4553639

Best,

Those little clamps for the SMD test pads are genius! I was trying to think of a good solution for that

[David Aurora]

Nice idea. I like it. Maybe I'll do something like that, too?

I think the good thing with rolling your own is that once you have the template you get lots of options, not just in terms of sockets but also in terms of filtering/probing/etc.

For example, with some stuff I'm doing I need fixtures in external boxes, but noise getting into the base connections becomes a problem so I'm using adapters to jump between coax and banana and it all gets bulky. So DIY adaptor boards opens things up to having shielded breakout boxes, or adding fuses, or whatever

[mawyatt]

Here's a link to various type adapters, we are delinquent in getting ours done

https://www.eevblog.com/forum/projects/smd-test-fixture-for-the-tektronix-576-curve-tracer/msg4553639/#msg4553639

Best,

Those little clamps for the SMD test pads are genius! I was trying to think of a good solution for that

Thanks, get the clamps with the pad that slides, this will allow greater use with small to larger SDM devices.

https://www.aliexpress.us/item/3256801104879812.html?spm=a2g0o.order_list.order_list_main.40.2ad118023rLHET&gatewayAdapt=glo2usa&_randl_shipto=US

We've had this ready to go for some time now, but haven't sent the PCB files off, waiting for another PCB fab to bundle up the order to save on shipping. That and we don't have an immediate need for the adapter/fixture now, however that may change soon 

Best,

[NF6X]

I picked up my new curve tracer on my way to work this morning. Well, "on my way" means a 2 hour detour in this case. Here are the physical issues I see so far:

• The left/right switch lever is bent, but it still seems to flip just fine.
• The offset mult knob is bashed in and flapping in the breeze. I'll need to get in there to determine the extent of damage.
• There is some knob crackage, but not as bad as many I've seen listed.
• It's going to be covered with dog fur from the back seat of my truck by the time I get it home tonight. 

[jonpaul]

Bonjour cher Monsieur

Bravo on the 576, a classic!

Used for SMPS design and consulting since 1980, found at Silicon Valley AARL ham radio Fleas.

we replaced the useless and awkward safety cover, the red warning light is enough.

Built a lot of DIY adapters with acrylic sheet and bannana plugs.

Some of the original TEK adapter sockets fail, eg the thin spring copper 4 wire contacts on the axial diode clip.

can take photos, happy to assist, contact me via PM if you like

Bon Soirée

Jon

see the groups.io tekscopes and tekscopes2 forums and Tek wiki W140 for manuals.mm

[NF6X]

Thank you!

Ugh, it sure frustrates me that I am stuck inside at work instead of playing with my new 576. Are any of you familiar with what should be behind that offset mult knob? If it's just a potentiomenter and counting dial mounted to the panel with a plastic bushing, then maybe my bashed one will just be a matter of fabricating a new bushing. But if that knob is supposed to be on a PCB-mounted potentiometer, then I'm worried about how much damage I might find inside.

[jonpaul]

the damaged control for offset is a Beckman Helipot 10 turn précision wirewound, with matching special 10t dial.  Most likely bent control shaft and ruined pot and turn counter dial.
They are 1979s classics, used,in a lot of mil and industrial, still made.  That control is seldom if ever used.

Check out Vintage Tektronix museum and Q service in Greece


Turn on carefully use Variac first time. look, listen smell for.PSU, HV faults.
Exercise all controls need cleaning.


Usual fail points.....CRT due to poor shipping package, or user misuse ( burning), loose CRT socket or nect pins, failing HV transformers and HV multiplier,
Scale factor   light pipe lamps ( hard to replace)

Left right switch is from Switchcraft.

Bon chance

Jon

[NF6X]

Good news! The 10-turn pot and counting knob both appear to be undamaged. The plastic bezel thingy which secures them to the front panel broke, and I ought to be able to fabricate a suitable replacement. Maybe I'll 3D print something, or maybe I'll turn something out of delrin. I'm not yet sure about why they made that plastic bezel thingy instead of mounting the pot directly in a smaller front panel hole.

[tautech]

Good news! The 10-turn pot and counting knob both appear to be undamaged. The plastic bezel thingy which secures them to the front panel broke, and I ought to be able to fabricate a suitable replacement. Maybe I'll 3D print something, or maybe I'll turn something out of delrin. I'm not yet sure about why they made that plastic bezel thingy instead of mounting the pot directly in a smaller front panel hole.

Check if Sphere have them:
https://www.sphere.bc.ca/test/tek-parts/tekpots.html

[NF6X]

It works!

I temporarily kludged the 10-turn pot to not short out anything nearby, brought the power up with a variac, and tried out a random diode I had laying about. I'm sure there will be things to fix, and I bet I'll need to calibrate everything. But it lives! As I suspected, the readout intensity knob just needed to be turned up to bring the readouts to life. I see some dead "pixels", so maybe I'll need to dig into the readout bulbs?

I'll start ordering necessities like tin/lead/silver solder. I'd like to find one of the safety covers so I don't have to fabricate one from scratch. I have one of the FET adapters sitting my in PO box waiting for me to pick it up already, and I still don't know how the other FET/BJT adapter differs. The only one I see listed is part of an expensive lot of 4 adapters.

[jonpaul]

Rebonjour NF6X:

Solder: The special silver alloy solder is used on the Tek ceramic terminal strips. A small roll is usually located inside the cabinet.

All the other solder joints are normal 60/40 or 63/37 Sn/Pb solder.

Cover Interlock: It is easy to open the   front porch and short or add a small toggle switch to defeat the HV cover interlock.

Fixtures:  test fixtures, original TEK, DIY acrylic two level  with banna plugs and test sockets.

Last  ... 576 with a typical TO-220 BJT.

Enjoy!


Jon

PS: These decades old TEK have plastic bushings, knobs, control whose plastic deteriorates and brittles, thue easy to break.

Most susceptible are the large contriol for V/H scale, steps, etc the Volts/power selector and the focus/intens

[Stray Electron]

It works!

I temporarily kludged the 10-turn pot to not short out anything nearby, brought the power up with a variac, and tried out a random diode I had laying about. I'm sure there will be things to fix, and I bet I'll need to calibrate everything. But it lives! As I suspected, the readout intensity knob just needed to be turned up to bring the readouts to life. I see some dead "pixels", so maybe I'll need to dig into the readout bulbs?

I'll start ordering necessities like tin/lead/silver solder. I'd like to find one of the safety covers so I don't have to fabricate one from scratch. I have one of the FET adapters sitting my in PO box waiting for me to pick it up already, and I still don't know how the other FET/BJT adapter differs. The only one I see listed is part of an expensive lot of 4 adapters.

   That's great news!  You'll like using that lead/tin/silver solder.  I now use that for everything. If you watch E-Greed rolls of the stuff still turn up there occasionally that don't cost both arms and both legs. My CT is missing the safety cover and someone installed a bypass switch on it and I'm satisfied using it that way.  If I allowed some ignorant parts-changer monkey to use the CT then I would be more worried about the missing cover but I learned LONG AGO not to touch any circuit under power.

[NF6X]

Those are some nice shop-made adapters there. I spent some stupid money (again, not adding it up) on several original adapters out of laziness, but I expect that I'll make a bunch more adapters of my own.

I don't think any of the shaft couplings are broken on mine yet. Yet. The display offset knob is not only missing a chunk, but the higher numbers on the clear skirt are smudged to the point of being unreadable. Rather than trying to keep this machine looking factory new, I think I'll upgrade any plastic stuff that I need to replace. I'm not sure what I'll do about the display offset knob, but I have a plan for the broken plastic 10-turn pot mounting cup: I have some brass round bar that is big enough, and I'll turn a deluxe replacement on the lathe at work next week! That part doesn't function as an insulator; the pot shaft is grounded to the front panel anyway by the rectangular plate that goes on the inside of the panel. I'm calling it a cup instead of a bezel now, because I found it in the manual and that is what Tektronix called it. I guess they might have done that because the front panel was too thick to get the turns counter to fit the pot properly?

I'd rather have a functional safety cover in place than routinely bypassing the interlock, but I'll bypass it for some careful testing before I get around to making a replacement cover. I gather from the manual that the early production models had an interlock bypass button? I presume that Tek's lawyers had a fit over that and made them change it.

[Johnny10]

There are so many great threads on the 576 on this forum.

And once you get one, you will want another !

[NF6X]

I'd think that I'd want a 577 for my second one, with its sexy storage screen.

[jonpaul]

Rebonjour had both 577 and 576.


577 has a store and nonstore version
the storage CRT is easily damaged by inexperienced users and burnin. With today's digital cameras and mobiles the storage features are not as valuable.

The 577 test fixtures include a rare opamp tester.

The 576, 577 voltage and current ranges are different.

576 has 20A pulsed capabilities and a special 100A pulsed current front porch

The protection cover is a poor design, delicate and awkward to use.

As we always start with the volts variables at zero, there is no exposed votage till we turn up the controls.

Finally the interlock switch mechanical is not reliable and may take fiddling to get the closed cover to release the interlock.

Guaranted disappointing!

Enjoy

Jon

[NF6X]

I have other equipment with storage displays. I just like the things, regardless of practicality.

[David Aurora]

I got a bulk lot of interlock bypass keys at a pretty good price, you should be able to find similar in your area:

https://shop.coles.com.au/a/national/product/coles-toothpicks

 

(Obviously never stick your fingers near a test fixture or show the work experience kid where you keep the box of toothpicks, but yeah- just jamming one through the hole works fine)

[CatalinaWOW]

You can find a file for 3D printing the safety cover here.

https://www.eevblog.com/forum/testgear/replacement-knobs-feet-and-fittings-for-test-equipment/msg3504168/?topicseen#msg3504168

[NF6X]

Thank you! I'll take a look at the cover.

I made a replacement for the broken plastic mounting cup out of brass, and I also made a spanner socket for the Kilo counting knob nut out of some 1144 steel. I had to get creative with the mounting cup dimensions, since I didn't have enough of the plastic cup left to measure all of its details. I am happy with how it turned out.

[CatalinaWOW]

That looks really elegant.  Only problem is that everyone will want one.

[NF6X]

Thank you! I think it will outlast the plastic one.

I considered just 3D printing a replacement, but the side walls of the mounting cup are pretty thin. I think the layers might separate under mounting tension. Then I considered turning one out of delrin... and then I remembered that lovely brass round bar I had left over from another project.

[David Aurora]

Thank you! I'll take a look at the cover.

I made a replacement for the broken plastic mounting cup out of brass, and I also made a spanner socket for the Kilo counting knob nut out of some 1144 steel. I had to get creative with the mounting cup dimensions, since I didn't have enough of the plastic cup left to measure all of its details. I am happy with how it turned out.

Oh snap! That looks killer!

[SoundTech-LG]

So did you get it all fixed up???  I spent some time gluing in the CUP tonight with JB Weld.
https://www.eevblog.com/forum/testgear/type-576-an-interesting-day/new/#new

[SoundTech-LG]

That brass cup redesign is a real Beauty!!! I want one!  But I already JB Welded the plastic one in there 

[pac1085]

That brass cup is really nice. I made a 3d model of the plastic one, seems to work fine, since a 576 I bought also had the thing flapping in the breeze like that... still need to find the knob for the tip of the thing though.  Looks like a Kilo / clarostat 461 but more $$ than I want to spend for a function I barely ever use.

https://www.printables.com/model/907974-tektronix-576-offset-multiplier-mounting-ring

[dxhydro]

Hello, Hope your 576 is well!
Were you able to find a mounting "cup" for the 10-turn pot?
I had seen 3d printing info and somebody else had turned one out of brass.
Just wondering if you have a line on replacement before I have one made.
Thanks! DX