It's a 1965 transistorized oscilloscope. I got it off ebay, and I did have a trace for a moment once, then shorted the AC somehow when wiring on a new plug, other things could have happened right before that too. I really don't know how it's aged or history. It looks incredible inside,very clean and gold and silver everywhere.I should have re-capped it 1st.
Here's the PSU
http://w140.com/tek_422_ac_powersupply.pdf
big schematic on p35
Since then I re-capped the PSU side, which is fully detachable from the rest of the scope. However I notice a bunch of voltages are way off. Wrote them all down. (some transistors aren't on ) All the main transformer voltages are also high. My household AC is at 123V. So I wired the T601 for 125V, before it was for 115V. It barely lowered any regulated voltages.
The -12V rail is -13.9, and with 100Ohm load went to -14.4V
The +12V rail is 17.7V, never loaded it yet
They should be +/-0.25V
The un-regulated 55V rail should be about 61V, I'm at 81V
So I put it on the auto-transformer, and the +12v at 17.7 pretty much stayed above 16-17V until I was under 80VAC for less, I check in more detail again later.
I had just put in a new D622, a 9V1 Zener, it's the reference voltage for the -12V reg. .It and the other 22V zener D655 both read fine.
For now , on T601 on page 35, I have un-soldered all windings except the -12V reg. So I'm going to apply an external +12V to R634 for the base and collector of Q633/34. Then see if the -12V reg. works or not, and check with the auto-trans too, if not.
Also, I modeled the PSU in LTspice, and it regulates just fine. However I really don't get where some of the listed voltages on the schematic come from. And even in the circuit theory part of the pdf. They have the top of the 9V zener at -6.9V on the sch., but say -6.4V in the text (on p12). But neither of those even makes sense for a 9V zener and a 390ohm resistor across 12V. LTspice agrees with me.
In real life it measures -4.6V, with -13.9V as (-12V) rail. and the 9V1 zener at 9.25V
Here's the PSU
http://w140.com/tek_422_ac_powersupply.pdf
big schematic on p35
Since then I re-capped the PSU side, which is fully detachable from the rest of the scope. However I notice a bunch of voltages are way off. Wrote them all down. (some transistors aren't on ) All the main transformer voltages are also high. My household AC is at 123V. So I wired the T601 for 125V, before it was for 115V. It barely lowered any regulated voltages.
The -12V rail is -13.9, and with 100Ohm load went to -14.4V
The +12V rail is 17.7V, never loaded it yet
They should be +/-0.25V
The un-regulated 55V rail should be about 61V, I'm at 81V
So I put it on the auto-transformer, and the +12v at 17.7 pretty much stayed above 16-17V until I was under 80VAC for less, I check in more detail again later.
I had just put in a new D622, a 9V1 Zener, it's the reference voltage for the -12V reg. .It and the other 22V zener D655 both read fine.
For now , on T601 on page 35, I have un-soldered all windings except the -12V reg. So I'm going to apply an external +12V to R634 for the base and collector of Q633/34. Then see if the -12V reg. works or not, and check with the auto-trans too, if not.
Also, I modeled the PSU in LTspice, and it regulates just fine. However I really don't get where some of the listed voltages on the schematic come from. And even in the circuit theory part of the pdf. They have the top of the 9V zener at -6.9V on the sch., but say -6.4V in the text (on p12). But neither of those even makes sense for a 9V zener and a 390ohm resistor across 12V. LTspice agrees with me.
In real life it measures -4.6V, with -13.9V as (-12V) rail. and the 9V1 zener at 9.25V