[GreenKeys] Questions Re: Model 15 TTY

[Jim Cooper]

On 14 Mar 2021 at 3:05, AA6RK via GreenKeys wrote:

>  I need help/advice starting the
> machine. 

basic first step:  turn the motor (in the proper 
direction!) by hand by turning the motor fan ... 
be sure there is nothing binding, jamming or 
'snapping' ...  watch all the levers, etc. and be 
sure they are moving as expected. 

Next create a "local loop" which historically 
has been a 120vDC source, a 5k (big watts) 
limiting resistor (adjust actual value to get 60mA 
in the loop).  It does not have to be very 'hefty' 
as you are only using 60mA (remember, watts 
are volts times amps ...  which is a mere 7.2 watts). 

Once you have 60mA in the loop, insert the M-15 
selector magnet AND keyboard contacts in series 
with the loop.  The selector magnet should pull up 
and when you rotate the motor by hand nothing 
much should happen except the main shaft turning. 

Press the R key on the keyboard and rotate the 
motor by hand again; you should see the selector 
magnet drop out (on space) and pull up (on mark). 
The baudot code for R is alternating space and mark, 
which should exercise all the levers and vanes in the 
printer.  If all is working well, the R code will be set 
up on the horizontal vanes at the front of the printer, 
and the R typebar will drop and be pulled up to hit 
the platen (won't really hit, as you are turning the motor 
slowly by hand).

If the R performs properly, then type Y - which is the 
opposite alternating code from R.  Keep turning the 
motor by hand and be sure the Y typebar gets selected. 

If all that works, you can turn on the motor and repeat 
at 'full speed' under power. 

de w2jc