Wondering if I’m doing something wrong with this transistor matching.
Tried my other DMM to confirm and apparently while it’s a $15 cheapie it does more sensitive mV readings than my Fluke (or I just can’t figure out the manual ranges on the Fluke.) But both meters are showing me 50mv differences between just about every transistor I test. (with the 2n3906’s I’m seeing between 54.5 and 55.7mv) From what I’ve seen on here from @ctorp (My build progress) and what Kassu posted on his blog https://kassu2000.blogspot.com/2015/10/transistor-matching.html ) I was expecting smaller differences.
But…I also tried swapping my reference for one of a set of matched values (i.e. one that tested as 55.0mv) and put in another that measured the same…and I’m still seeing 55mv difference between them even though they both measured 55mv against the reference I used.
I’m suspecting the value I’m seeing is more just a difference in measurement accuracy from my DMM’s than a difference in the transistors. And questioning if I did something wrong. But I used two 100k resistors that both measured the same and have checked the circuit a few times. I’m just using a 1n4148 for the diode…none of the articles I read were specific about what diode to use since it’s just about the voltage drop apparently…