[GreenKeys] Model 14 typing errors - lubrication problem? Misadjusted? Wrong selector magnet wiring?

[Jim Haynes]

Is it a Western Union machine or Bell System or otherwise?  I've had
a similar problem with several Western Union machines.  Had to take
the selector apart and found a green varnish-like substance on the
separator plates.  Apparently W.U. used some lubricant that was not
compatible with the plating on the metal.  Or at least the W.U. facility
where those machines came from.

Back in earlier times we were told to use non-detergent oil because
detergent oil would turn the springs green.  Which means some chemical
reaction with the nickel plating that Teletype used on practically
everything.  Nickel compounds tend to be green.  Perhaps modern oil
detergents don't have that reaction, or maybe it was an old myth to
begin with.  It's hard to find non-detergent engine oil these days.

Is it a holding magnet selector or a pulling magnet selector?  The
holding magnet selectors are designed to have the coils in series or in
parallel for 20ma or 60ma line current.  The pulling magnet selectors
are designed to have the coils in series for 60ma line current.

You could put a rheostat in series with the line and measure the current
at which the selector magnet pulls in and at which it drops out to see
if that is centered on 30ma.



jhhaynes at earthlink dot net