[Bret L]

The more I think about these things, the more I am convinced that
you, too, need to think about these things.

Every hi-fi, pro audio and MI electronics repair shop had one of
these or of the copies that sprang up once the basic patent ran out.
They used them for phasing out transformers, measuring their turns
ratios, checking speaker polarity and the proper operation of
crossovers, and whatever else might be needed in a shop of such a
unit. If the neighbors had the ballgame up too loud, if the station
broadcasting the game was on the lower end of the dial they would hook
a long wire up to the output and swamp out their radio with RF or
create a nasty heterodyne howl. They were sufficiently low in
distortion that they could be used with the early distortion
measurement sets which didn't have their own generators, or be used to
drive an amplifier if one needed variable frequency AC for a few or
few dozen watts.

Utility isn't the main reason I write of them here. It's the elegance
of their design and the excellence of their manufacture. Most of the
ones that haven't been destroyed or dumpstered by idiot institutions
still work. And they will still work, perhaps with new electrolytic
caps and a few new resistors and an occasional new tube, when I am
dead and buried.

I get a certain satisfaction out of that.