There is a GTC-1212A curve tracer a Goodwill product on ebay right now selling for $169.95 plus 16.45 shipping. Very little information is available for this unit, but if you look close I would guess its the same as the Leader LTC-905, which has all kinds of free info information including the service manual online. This might be worth checking our as Leader Test equipment is well made.

It took about a year of looking before I scored on that. It was marked "parts only", although it did come with the 177 test fixture. The left/right switch is broken (I've seen that happen quite often with that unit). Turned out to be pretty much functional, although I still have to go through it. For most quick test work I usually use a 7ctn1 plugin on one of my 7000 mainframes. That works great for low power devices.

I always buy test equipment marked "parts only" on ebay. I've only been really skunked a couple of times; most items require minimal or no repair (I've had a couple of items where the only repair needed was flipping a switch). The worst deals come from sellers who know exactly what they're looking at. Right now I have around $100K (original list price) of test equipment surrounding me that I payed somewhat less then a penny on the dollar. That's part of the fun for me.

If you want a guarantee of a working unit you're going to pay significantly more. I do think that DCA75 looks pretty good.

The 570 and 575 are serious machines and valuable still today. We actually used the 570 as a Cathode Ager for modern image tube manufacturing.

The 575 can be used with all semiconductors. Actually used mine to test silicon die/wafers of multiple diodes. The 575 can also be used similar to a Huntington Tracker.
Both instruments have dual channelS so you can compare and match d.u.t.

I collect Tektronix 500 series and still use them, (my 547 every day). Like my Simpson 260, they are still useful. They take a lot of space, generate a lot of heat, and costly to run, but they have big knobs, markings easy to read, and are easy to use.

What's wrong with a homemade octopus?
That's all the early Huntrons were basically.

https://www.youtube.com/watch?v=Gwo3pEH7hUE

I also looked at building the octopus but that would limit me in comparing power transistors and testing transistors / diodes at higher voltage levels. I thought a "3 wire type" curve tracer can also perform as a signature analysis tool similar to the Huntron using the C-E test output?


I looked at the GTC-1212A curve tracer and I agree that it's probably a Leader LTC-905. I was thinking about getting the Leader since I have the manual and calibration guide but I got my hands on a clean Heathkit IT-3121. I thought the Heathkit had slightly more options in case I wanted the flexibility and would be easier to maintain. Unfortunately, after I received the unit, the unit did not work as designed but did manage to send out the ever familiar smoke signals... Ughhh... maybe I should have bought a factory made Leader.

Steve,
Would you be able to post a pic of the staircase wave your unit generates? I would like to compare that waveform to my unit. My horizontal steps look a little odd.

Thank you

Here ya go. Note that the scope input needs to be DC coupled on the input to get nice squared off lines. With AC coupling, capacitor affects alter the waveform as in second image. All settings on the Heathkit were set to C with the exception of the step selector which was set to volts. The scope was hooked up to the Base and Emitter jacks on the Heathkit.

Steve

Thanks for posting the setup and the waveforms. I didn't have a "C" labeled setting on my 3121. Looks like my traces will need some work. The first pic is using the cal setup and the second one has the settings you've suggested.