Awl --

Guess what.... of course it didn't lite up! Seems like the sodium bulbs
were mixed in with the metal halide bulbs, in the hardware store, and I was
just looking for "70W".

The Q is: Did it harm the ballast? The bulb was in there for a few
minutes, while I mucked around (25 feet up in a tree), tryna figger stuff
out, before I noticed the "MH" designation on the bulb... A short length of
the glass stem glowed very slightly.

So, I disconnected the fixture (70 W) from power altogether, until I can
(hopefully) exchange the bulb.
I doubt the bulb was harmed. Man, these things aren't cheap.... almost $22
for the metal halide bulb.

These bulbs are really inneresting in design. Not sure what does what, but
the insides are neat.
I assume most of these bulbs are similar to regular ole fluorescents in
principle, where the atom at hand needs to be vaporized, then ionized
(ignited), then kept in a steady state current.
--
EA