Semiconductor Curve Tracers

[nevetslab]

I was wondering who out there is using Semiconductor Curve Tracers and what manufacturer's have you found to be acceptable/easy to use. I still have my B & K Precision 501 that I had purchased back in 1975, and is here in my shop, though I haven't used it since the late 70's or early 80's. Probably still works, would no doubt need some service on the rotary controls.

Still looking for help in figuring out what has caused the baseline shift on my Hameg HM8042 which I just posted an update to the thread I began back in November 2022, when I sampled several possible replacement Digital Encoders for this instrument.

I looked on ebay a couple days ago to see what was out there for other quality Industry Curve Tracers. Most selling for the price you'd pay for a decent used car. Well beyond my budget.

[dmeek]

I have Tektronix 577 I got for a very good price many years ago. I also have a 7CT1 plug-in for the 7000 Series Not as powerful but still useful and not as
expensive these days. I think I paid $100. You would need a timebase with external horizontal amp input or you can plug it in the horizontal slot.

[mozz]

DCA75 might be able to do it. I have the DCA55 and have the 75 model on my want list.

[drewl]

Tek 576 in the lab at work.
We've had one of these in three places I've worked.

[Mars Amp Repair]

I worked at Echostar for a few years about 8yrs ago or so, that makes the set-top boxes for Dish as well as the LNB's for the dish itself. Of course they had whatever test equipment they needed in the labs there. I was working 'qualifying' components which meant doing a billion tests on items like electrolytic capacitors to inductors to semi-conductors, solely for the purpose of verifying the manufacturers specs. It as basically the equivalent of a Grunt job in electronics. The job no engineer wanted to do.
Many of the components they sourced from foreign parts mfg's were not rated properly, and owing to the millions of boxes they mfg'd and distributed, they couldn't afford to have parts going bad.
I believe they created that department owing to all the faulty electrolytic caps that we all have experienced which I believe were sourced from Taiwan, but don't really recall. ANYWAY to make a long story longer, they had one of the Tektronix 576 curve tracers that albeit quite old, we used in one of the tests for semiconductors...PHEW.
It was an interesting job and I was amazed that some of the tests on something as simple as an inductor could take MONTHS to complete. It actually bored the hell out of me as I wanted more instant gratification like repairing an amp .
You could get thru a couple of weeks of testing one component and be told that one measurement out of hundreds that you made was suspected of somehow being corrupted, and told to start all over again!
UHGGG!
Anyway, part of the past & I did learn a lot being my first, and only, job in an actual lab.

[nevetslab]

DCA75 might be able to do it. I have the DCA55 and have the 75 model on my want list.

While this Atlas DCA75 looks on the flimsy side of what I'm used to, immediate limitations being the very short midget-sized EZ-Hook Test Clips, they could be extended with a connector to serve as a better interface. I downloaded the manual for it and the instrument IS very affordable, so I might just pick one up to see if it has merit relative to what I'm used to. My present Hameg HM8042 is still in the repair-status with a baseline issue in its' limited voltage range sweep max of 40VDC, and has a new Current offset that increases with voltage on the baseline (seen without a component inserted).

I did own a TEK 7CT1 which was in the collection of Tek instruments on my well-equipped Tek Scope Cart that had my 7834 Storage Scope & lots of plugins, TM504 mainframe with AA501/SG505's, DMM's and PS503, and other gear on that one rollaround test station. Still trying to find the chap I was working for where it was parked, and now has disappeared along with my gear and tools. Sigh...

A Tek 576 was one of my desired proper curve tracers, though I've never had one. We had a Tek 575 curve tracer at BGW Systems when they were in business (spent 22 years with them), though that instrument left you wanting something better.

[nevetslab]

I worked at Echostar for a few years about 8yrs ago or so, that makes the set-top boxes for Dish as well as the LNB's for the dish itself. Of course they had whatever test equipment they needed in the labs there. I was working 'qualifying' components which meant doing a billion tests on items like electrolytic capacitors to inductors to semi-conductors, solely for the purpose of verifying the manufacturers specs. It as basically the equivalent of a Grunt job in electronics. The job no engineer wanted to do.
Many of the components they sourced from foreign parts mfg's were not rated properly, and owing to the millions of boxes they mfg'd and distributed, they couldn't afford to have parts going bad.
I believe they created that department owing to all the faulty electrolytic caps that we all have experienced which I believe were sourced from Taiwan, but don't really recall. ANYWAY to make a long story longer, they had one of the Tektronix 576 curve tracers that albeit quite old, we used in one of the tests for semiconductors...PHEW.
It was an interesting job and I was amazed that some of the tests on something as simple as an inductor could take MONTHS to complete. It actually bored the hell out of me as I wanted more instant gratification like repairing an amp .
You could get thru a couple of weeks of testing one component and be told that one measurement out of hundreds that you made was suspected of somehow being corrupted, and told to start all over again!
UHGGG!
Anyway, part of the past & I did learn a lot being my first, and only, job in an actual lab.

I never had the funds when I had come upon a reasonable deal for a TEK 576, and in spite of it's age, they're still very appealing to me. I've owned several Tek 5030/5031 instruments, which looks like the same CRT used in the 576. Same fiber optic readout system adjacent to the large CRT. I know there are some 576's that have been modified for use as a Vacuum Tube Curver Tracer besides being used over a very wide range of voltage/power levels with semi's if you have all the additional options for that instrument. I'm a big fan of Tektronix, and have invested in a lot of 7000 series instruments. Work horses that, with care and feeding, last decades!! My kind of gear!

[mauman]

+1 on the DCA 75, it's pretty slick using the USB interface and their app. I've had good experiences ordering Peak products directly from their factory in the UK, even though I'm in the US. Here's a video rundown on a slightly older version of the DCA 75: https://youtu.be/cWqeyn17Vac

[nevetslab]

+1 on the DCA 75, it's pretty slick using the USB interface and their app. I've had good experiences ordering Peak products directly from their factory in the UK, even though I'm in the US. Here's a video rundown on a slightly older version of the DCA 75: https://youtu.be/cWqeyn17Vac

I watched that YouTube video yesterday, then ordered one of these from Walmart, which should arrive this Saturday. I'll install the USB Interface on my laptop (WIN 10 O/S). I'll end up replacing the short leads to their mini EZ-Hook terminals to a connector so I can extend it to make it more flexible and fixtured. Even though the voltage range is VERY limited relative to a proper Curve Tracer in the mulit-thousands of dollars class, it still LOOKS VERY capable.

I will continue digging into my Hameg HM8042 for a solution to the error found in the baseline. And see if I have what I need to construct an extender cable into the Hameg Mainframe HM8001-2. I do have a couple Vector 3690-6 12" Male/Female 22/44 pin Extender cards that I think mate with the system. I have something else on the bench at the moment to verify this WILL extend it out past the front of the mainframe. I'll report what I find and create with the little cute DCA 75 after I see how it works with the USB interface.

[GoldtoneWorkshop]

I have the DCA75 and it's a great go/no go for transistors, especially small signal ones. It will however pass transistors that actually fail at higher voltage, which can be misleading. I also have a Tek 576 that is in great condition overall, but arrived without the high voltage settings working. Gotta dive into it on a day off at some point to see where the fault lies. The protective cover was bypassed on the one I have, but the light still illuminates to show that the collector supply voltage is disabled. Can't wait to get it working!

[mozz]

I would order from Newark. Be afraid of a fake from Walmart.
Don't cut the mini clips off the DCA75. They are high quality units, clips, the unit is not flimsy. I have tested 1000's of small signal transistors germanium/silicon with it. Get a zif socket and solder it to the perf board with the solder pads underneath. Then make 3 loops or 3 pins which to attach the clips. I have also soldered a transistor socket for TO-5 so i don't have to bend leads. You can wire the zif socket many ways if you need certain spacing. Also recommend a good lithium battery so you won't have to open it to change it too often.

[nevetslab]

I would order from Newark. Be afraid of a fake from Walmart. .

Opps. Too late. Have you heard of any 'fakes' of this DCA 75 out there?

Sounds like a good solution with the ZIF Socket. Seems like I have a spare of those around here someplace. Good suggestion on the Lithium battery.

[mozz]

Not really heard of that item being faked but you never know. I try to stay away from Amazon and Ebay when dealing with electronics. I think Walmart is just trying to get a piece of online shipping action by advertising lower prices. Where they are buying from or whether they are an authorized seller i don't know.

[nevetslab]

Last Saturday, I got emails from Walmart indicating they had delivered my DCA 75 Curve Tracer. I was home all day, though never did go outside, while the front door was open, screen door closed. I found the email Sunday morning, then went to look. Nothing anywhere on either floor, nor at any of the other apartments. I had received an updated email from Walmart stating the package would be delivered late Monday and not Saturday. When I got home from the shop on Monday, I found the package in my mailbox, it having been shipped via USPS with a tracking code, which explains WHAT that package shipping notice I got from USPS was about. So much for Walmart's shipping intelligence.

The USB cable (USB-B) has at the other end a small connector that I first thought might be USB-C until I looked at it close. Unique connector, NOT USB-C. The USB Software loaded into a USB-B Thumbdrive. I haven't yet loaded it into my laptop.

I did look briefly at the unmarked 2SK1058's and 2SJ162 parts I had received, prior to getting the Exicon ECX10N20 and ECX10P20 parts on the DCA 75. They appeared to be functional parts, though no idea who the mfgr is. Print on the part bodies very faint. I'll know more when I get the software installed, and then also check them and the Exicon parts on the now-restored Hameg HM8042 Curve Tracer. Odd not to have specific cable/connectors labeled, and instead the instrument tells you what is connected to the three different colored wires/connectors.

Onward