[GreenKeys] Just brought that Teletype home ? Do this FIRST

[John Nagle]

> Date: Mon, 26 Jun 2017 12:51:07 -0700
> From: Pete Lancashire<pete at petelancashire.com>
> Subject: [GreenKeys] Just brought that Teletype home ? Do this FIRST
> 
> Check the fuse(s) for the correct amperage !
> 
> In this case the motor fuse should be 2-1/4 Amps, even has a paper label
> saying such.
> 
> Fuse inside was 10 A.

     I've received a Model 15 with a 15A fuse in the fuse
holder.  It's supposed to be a 1.4 amp Fusetron slow-blow.

My electrical checklist for newly received Model 14/15 machines:

- Check for broken insulation, especially on the motor leads and
power cord. That may need replacement.

- Model 14 machines usually need a complete rewiring if they
still have the original varnished fabric insulation.  Model
15 machines use General Electric Deltabeston felted asbestos
insulation ("will not age or crack"), and it's usually fine.
But don't strip those wires and let the asbestos out;
cut them out entirely if you have to replace.

- I install a 3 amp breaker or fuse in all Model 14 machines.
They totally lack any built-in protection.

- Use ohmmeter to check for shorts between either side of
motor power and ground. Motor should be totally isolated
from ground.

- DC resistance of motor should be about 4 ohms.

- Check printer and keyboard cables. Resistance of the
printer should be around 55 or 220 ohms. Printer should
be isolated from keyboard and from ground.

- Turn motor counterclockwise to see if mechanism is
jammed.  Mechanism should cycle.

- Turn motor CCW until selector magnet moves freely.
Then apply a 9v battery to the printer connection.
The selector magnet should click.

- Using a GFCI and an outlet strip with a circuit breaker,
attempt a motor power-up from a safe distance.

- If the machine will run open, apply the 9V battery
again to see if the clutches will disengage and put the
machine in a normal idle.

			John Nagle