Woo hoo! Whoops, what a doozy. 43 volts is good yes!!
Thanks Nick, spot on.
Yep, "that's good enough for Australia"
BTW that Tenma DMM in your picture should be the UNI-T UT139C. I have one. Pretty good features for the price and a big read out. Reliable measuring vs my Fluke 87V and Brymen BM257s. Little slow auto-ranging in resistance mode, but not too slow, in all other modes fast enough. But I don't like the short 15sec back-light auto off, the small print blue letters around the switch, and all those function signaling beep sounds.
Look well into such models including the Rigol DS1054Z, check their reviews and options costs, also think in terms of a signal generator's cost too. All those mentioned are smoother displaying faster capturing newer gen "economic" category scopes. You will keep this tool for many years to come and it will teach you a ton because you will be able to actually see and analyze your signals now, wow! Try make a balanced long term standing buy.
More R3x value will do, you are near. If you now got 9.1k replace with one 11k resistor or two 22k resistors in parallel for 11k. Can hide one at the bottom side. That should give useful 30.5V to 35.7V adjust range with the 2.56mA current you probably now got in the Vref.
Do try 10k R3x that you got in hand for now. It will maybe suffice for your TP1-TP2 adjust needs. I can't be sure of the exact JFET current you now got in the Vref. I am speculating it from your results but there is some tolerance. The other channel might not need something else even, depends on what Q3x JFET IDSS it chanced.
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