[GreenKeys] ok here is my RO 28 I am shoving keyboard into to go over on display at the

[Jim Haynes]

That one has a Western Union LESU instead of one by Teletype.  I once
traced out the wiring of that thing, but I don't know where I put the
diagram after I did it.

Teletype bought a lot of relays from Automatic Electric - the company was
not required to use the parent company's relays and other products.  It
was often easier to use products from other companies, because some
Western Electric items were only manufactured when they were needed;
and because the other companies were interested in selling their products
on the open market, so they had sales organizations and catalogs that
Western Electric lacked.

The polar relays you have there were designed by Western Union - see
Western Union Technical Review for January 1952, p. 29.  They chose
Automatic Electric to manufacture them, and A.E. was licensed to sell
them on the open market as well.  Teletype apparently thought that
relay was superior to the W.E. 255A, and it was certainly smaller.
A.E. was persuaded to make the relays with a base that made them
interchangeable with the 255A.  Later Western Electric came up with
a replacement for the 255A that used a mercury-wetted contact
assembly and was non-adjustable.


jhhaynes at earthlink dot net