I'm rolling right along with this project. Cid Vance sent me a decent cabinet and a nice front panel. I'll probably start building this thing next week. Dumb question time.
I have a DX-20 that was modified with a 3-wire power plug AND a ground lug. I've seen AT-1 xtrs modified with a simple polarized plug. The original was "non-polarized" and had no ground lug. I would prefer to go with a 2-wire polarized and add a ground lug. I've converted a hallicrafters WR-600 to polarized 2-wire, but that was AC/DC to begin with.
Should I tie the "ground" side of a "modern" polarized AC plug to the AT-1 chassis and add a ground lug to the chassis or go with a 3-wire?
My confusion is with the original AT-1 wiring which uses a non-polarized AC plug and NO ground lug. Since the main function of the "reborn" AT-1 will be as an exciter, it will have to be at the same ground potential as the 813 amp regardless.
Mike, you must be extra careful with everything you're doing with this project. Check with us often.
To answer your question, DO NOT connect either side of a two wire polarized line cord to the chassis or any other ground. Connect the hot leg of the cord to your fuse then to the on-off switch then to one primary lead of the power xfmr. The neutral leg (this is the wide blade on the plug) gets connected directly to the other primary lead of the power xfmr NOWHERE ELSE. You can then connect the chassis to the station's metal ground point with a separate piece of wire. OR, you can install a three wire grounding line cord in the chassis. Connect the black (hot) and white (neutral) wires of the cord the same way I described above. Connect the green ground wire of the line cord to the chassis with a ground lug.
DON"T get creative with connecting the power cord to your project. Follow my directions.
Fred