I was wondering if anyone could tell my why my PS would drop voltage with it only pulling about 5-10 amps. I have replaced all the "pass transistors"? (TO-3)
Have a look at the unregulated side (at regulator input / filter caps) under load. Things will never work right if voltage is already taking a nosedive there - I imagine it should always remain above 15-16 V or so, with manageable ripple (AC). If it doesn't, look at transformer connections and filter caps, or the classic corroded fuse holder.
Otherwise you'll have to look more into the regulator and current limiting. The current sense resistor may have gone high or a transistor gone leaky, making total current gain insufficient under load. At up to 46 A continuous and 52 A peak, I imagine you'd need a total beta of about 50000, so driving the pass transistors would already take a moderately beefy Darlington or two transistors.
This page has a PS-52KX schematic, I guess that's what you need. Mind you, linear regulated power supplies tend to be fairly similar either way.
So looks like this one is based around the trusty µA723 regulator IC driving a TIP41C (check that one) which in turn drives 4x 2N3771 via a thermal cutout (check its resistance) and individual 2.2 ohm base resistors (check those). If you can't find anything, check every other resistor and diode, and generally inspect solder joints.
Interesting. This one seems to generate an elevated supply voltage that's basically "propped up" on top of main unregulated supply in order to feed the µA723 and TIP41C. Makes sense as it gives them the necessary voltage headroom while keeping pass transistor dissipation to a minimum. That 1000µ/16 filter cap for the aux supply may have seen better days by this point, though I don't think this would cause the voltage to sag this badly.
Otherwise you'll have to look more into the regulator and current limiting. The current sense resistor may have gone high or a transistor gone leaky, making total current gain insufficient under load. At up to 46 A continuous and 52 A peak, I imagine you'd need a total beta of about 50000, so driving the pass transistors would already take a moderately beefy Darlington or two transistors.
This page has a PS-52KX schematic, I guess that's what you need. Mind you, linear regulated power supplies tend to be fairly similar either way.
So looks like this one is based around the trusty µA723 regulator IC driving a TIP41C (check that one) which in turn drives 4x 2N3771 via a thermal cutout (check its resistance) and individual 2.2 ohm base resistors (check those). If you can't find anything, check every other resistor and diode, and generally inspect solder joints.
Interesting. This one seems to generate an elevated supply voltage that's basically "propped up" on top of main unregulated supply in order to feed the µA723 and TIP41C. Makes sense as it gives them the necessary voltage headroom while keeping pass transistor dissipation to a minimum. That 1000µ/16 filter cap for the aux supply may have seen better days by this point, though I don't think this would cause the voltage to sag this badly.