thebest1 - try this
1) Set your background color to white.
2) Copy then paste as transparent selection.
3) Rotate right 90 degrees.
4) Do a smart resize down to 30 - 40% or there abouts
The jaggies all disappear on the resize.
Basics -
Get the original picture.
Rotate or whatever is needed to get a nice side on view.
Create new layer.
Use a single pixel brush to do the letters.
Resize using pixel resize by 200%
Smooth out tidy up letters.
Then follow above instructions (1 - 4) but changing the resize as appropriate.