Yie, yie yie!
From olden days, it always excites me to see the key, a good ground,
and a 117vac plug
connected so intimately!
Many years ago I started collecting stuff to make something like you
have in your hands, but
fear and common sense always made me chicken out.
I Googled for a while, and the following is the closest I could find,
and it isn't
even a 117N7, but a 50C5 with a heater series resistor.
http://www.kb7tbt.com/manuals/Ham%20...0Designs.p df
Sit on a dry wooden chair, with your feet off the ground, and one hand
in your pocket.
Good luck,
Old Chief Lynn, W7LTQ