In Need of info about Hobart TDU-292 welder

[metalurge]

I bought an old Hobart welder the other day, and I was wondering if anyone had a manual or wiring schematic for it. I'ts a Hobart model TDU-292 I called Hobart and asked them for a manual, but apparently for some reason they got rid of almost all of the schematics and manuals for their older machines . All they could tell me was that the welder was made in 1957, and they had just the first 5 pages of the manual on PDF for that model. No schematic and no other info.
The welder has a large knob on the front and a tag showing the settings for ac current numbered 1-5 Theres another tag on the front stating that the settings ABC or D were to be used only for Heliweld. I tested those settings with a volt meter and tried welding on those settings, all settings seem to put out only AC, no DC voltage.
So if anyone out there is familiar with this machine, please let me know what in the world these ABCD settings are suppose to do, and if someone has a complete manual, I'd appreciate a scanned copy of it.
Thanks

[metalurge]

Photos of new old Hobart TDU-292

[gizzardgutz]

What you have is an AC only machine unless it's been modified. Heliarc welding is what we used to call GTAW (gas tungsten arc welding), with the proper set up that machine will probably do aluminum.
http://www.hobartwelders.com/weldtal...on-this-welder