[GreenKeys] Model 15 parts wanted

[John Nagle]

> From: Gary Schulz <gary.schulz at ubnt.com>
> Subject: [GreenKeys] Model 15 parts wanted
> 
> This is my first posting to the greenkeys list.  I am attempting to
> resurrect my model 15KSR and other accessories that I last used for RTTY
> circa 1978.  This equipment has been left getting pretty dusty ever since
> that time.  I just brought it all home and I am wondering what the proper
> sequence is to bring this machine up after all those years.  There is no
> rust on any of it but it is covered with a heavy layer of dust which has
> accumulated on all the oiled areas.  Some of the cords are getting a little
> stiff and I don't want to cause further harm.  Do you need to worry about
> the capacitors going bad like you do on all the other old radio equipment I
> have restored?  I presume these are for motor start and other related
> functions.

   If there's no rust, just dust, it should be straightforward to get it
going.  Here's the cleaning procedure I use:

   http://www.aetherltd.com/refurbishing15.html

There are links to the Model 15 manuals on that page.  After
cleaning, you have to re-oil everything, for which there is a
procedure in the manual.  You'll need oil. This is much discussed,
but the lightest grade of synthetic motor oil is a good choice.
Do NOT use WD-40.  You also need lithium grease and a small
grease gun, and for the gears that tend to throw off grease,
Lucas Red N' Tacky Grease.

If both of those tests work, it's usually safe to power up.

A Model 15 doesn't need any capacitors to operate.  They're just
for RF suppression.  If they're shorted or leaking, cut them out
of circuit for now.  Later, replace them with modern capacitors.
Early capacitor technology wasn't very good.

If the power cord is cracked, replace it.  I use rubberized
3-wire cord to match the original, attach the grounding
conductor to the machine frame, and put a big rubberized
modern 3-prong plug on the end.  The internal wiring in
a Model 15, except for the motor leads, external cords, and
anything somebody added on, is General Electric Deltabeston felted
asbestos ("will not age or crack", said the advertising, and
it doesn't) and should be intact.

Basic mechanical checks before powerup:

- Turn the motor fan counterclockwise and watch the mechanism
cycle.  See if anything jams.
- Lift each typebar up to printing position and see that it
moves freely and falls back.
- Gently push the selector magnet armature against the
selector magnet and hold it there.  Turn the motor fan
counterclockwise.  After a few turns, the clutch should drop
out and the printer mechanism will stop moving except for the
shafts.  Then release the selector magnet armature and keep
cranking. The print mechanism should start cycling again.

If those three tests work, things are in good enough shape
to run the machine on motor power.

Blow out the motor with compressed air, check its resistance
(which should be about 4 ohms), add a few drops of oil to the
two oil fillers on the shaft (one is inside the fan, which
is a reason to buy that long precision oiler I recommend)
and power it up cautiously.

Using an outlet with a GFCI, or a standalone GFCI, is recommended.
A small amount of arcing in the starting switch during the
first second of motor start is normal. After that, the
motor should not arc at all.  If you smell any ozone after
a few minutes of motor run, the motor starting switch needs work.

Once you get through the basics above, it's time to find something
to connect the machine to.  That's another subject.

				John Nagle