Reverse-engineered schematic of my 250 PSU (came with my Argonaut 505).
I bought a somewhat dilapidated Triton II from a CTARC boot sale. This somewhat dilapidated PSU came with it. It definitely had a DPO.
Said DPO fitted a second 2N3055 in parallel with the existing one. Parts of this job is nicely done, like the mounting of the heatsink and the two emitter resistors.
Other bits are just plain ugly, like this solder joint.
Also, he removed the over current SCR, and fitted that humungous 2N3670 16A SCR straight across the output -- proving that he doesn't understand the Ten-Tec SCR which shuts down the voltage regulator without popping any fuses. But he left the gate unconnected to anything but a pull-up resistor, so maybe he never finished the project. Who knows.
I first thought he might have added the second 2N3055 to spread the heat out a bit, but the shenanigans with the SCR tells me that he was trying to get more current -- which is strange, because the transformer can only deliver what it's rated for. And in any case, it would have been a helluva lot simpler to just fit a 2N6258 transistor like the 252 PSU uses.
Anyway it's back to stock and back together now. Ready to work with a (100W) Triton I, and not a 200W Triton II or Triton IV.
I made this copy waybackwhen, from Jacques ZS1PL's documentation of his 251 PSU (he had an Argonaut 509).
This came with my Triton IV. It's unmolested, it works, all good.
Swapped this one for a Yaesu FT-DX-400 I saved out of an estate. Again, there are some signs of a DPO, but nothing too egregious.
The 262M was designed to work with the Triton IV (540 and 544), so it's good for just over 225W DC, also it has a VOX facility built in (maybe there was no space in the Triton IV for VOX?).
The strange thing about the 262M is that there are no manuals or schematics anywhere on the internet. Some investigation shows that the control PCB is identical to the one in the 251, and some tracing confirms that this is just a scaled-up 251. Differences are a BDY58 pass transistor, two ceramic capacitors on the incoming mains to ground, 19000uF 25V for C1, 1000uF 25V for C2, and (obviously)a heftier transformer. Some components on the PCB might have slightly different values, I did not check. My unit has some rewiring on the mains side, the on/off switch loop through the power connector's been dyked out, but I assume it was there when the PSU left the factory.
The incandescent bulb behind the meter is wired between AC and R1, and the R1 terminal is also grounded. R1 is fairly large (2W?) and 470R.
The VOX board is 90406, with a uA747 dual 741 and 10 transistors. Some of the pins (3, 5, 8, 11, 14) are cut off and don't go through the PCB (there are no holes).
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