I have the DCA55 and I’d say it was worth the splurge.
As someone who has killed many a cheapo tester, the sturdier & more accurate DCA55 is worth the money if you're looking for a long-term solution. I only wish it could also measure JFET Vp & Idss, as that would make it the standout option over cheaper testers. Unfortunately, only the DCA75 does that, and it's $130 vs. $60 for the DCA55I have the DCA55 and I’d say it was worth the splurge.
As someone who has killed many a cheapo tester, the sturdier & more accurate DCA55 is worth the money if you're looking for a long-term solution. I only wish it could also measure JFET Vp & Idss, as that would make it the standout option over cheaper testers. Unfortunately, only the DCA75 does that, and it's $130 vs. $60 for the DCA55
I do the same with a veroboard matcher and it works great! To more easily compare JFETs for matching, you can also calculate Rds(on) from:I contemplated getting a DCA75 when I was making my Aion Ares, but since I only use JFETs sparingly, it's more economical to just whip up a JFET tester on the breadboard when I need it.
I made myself a RG Special and carefully selected the two resistors like RG notes in his article. No math is involved, you just have to move the decimal over 1 place to get actual values.
I even use this tester for silicon transistors, which 99.9% of them show zero leakage, but the tester works great for silicon BJTs also.
I even installed a charge pump in the box and a 9 volt regulator so a battery going south won't affect the results.
Highly recommended and a super easy build!
We're big fans of the TC1! We have them all around the Cusack campus, great little tester for all sorts of things and super simple to use.
As discussed, it is not the perfect tester for germanium transistors. It will get you in the hFE ballpark (reporting higher from leakage). We'll sometimes use it as a second opinion or if we need to do a rapid test of a bunch of germanium. We use RG Keen's method as our primary test for sorting.
That's definitely good news to hear. Curious.... similar readings for hFE or Iceo and leakage (or both)? I was testing a few hundred transistors last week and the readings were not the same. In the ballpark, but definitely not the accuracy we wanted. That said, it was a terrible batch, almost all unacceptably leaky and we ended up rejecting the whole batch as less than 20% were useful and almost none in any of the "sweet spot" gain ranges.This is interesting to me as my personal tests, with a TC1 and breadboarded RG tester side by side, show striking parity between the two in almost every device I’ve ever tested.
Not accurately (or perhaps hit/miss is a better descriptor). It’s great for quick measurements of caps, resistors and silicon transistors. I’ve got this one and the TC-1, they’re almost identical. The TC-1 turns on and tests a bit faster but they’re both great for what they do. I think the DCA55/75 is about the only thing that measures GE transistors anything near accurately aside from long form with a DMM.Will that measure germanium leakage?