[GreenKeys] auto cr/lf

[WA3FRP at aol.com]

Eugene,
 
Two things may be involved here:  Non-overline and auto  CR/LF. 
 
If the problem occurs on ever line regardless of length, you need to remove  
or disable  non-overline.  You can usually do this by swapping  the universal 
codebars in slots 5 and 38 of the stunt box.  See details  below for 
particulars.  
 
If "Miss Sweden" is longer than 73 characters long in some places, then  
automatic CR/LF also needs to be disabled.  You can easily do this by  removing 
the "bit from the horse's mouth"  -  also know as mod kit  157514.  Look at the 
right side of the line printer above the   piston used to slow the carriage 
when CR is selected to the spacing drum – the  round metal object that slowly 
turns as the carriage spaces across the  page.  The description is below.  
Simply remove the screw and the  "bit" and automatic CR-LF will be disabled.
 
Now the details...  
 
 
      What is Non-overline?
 
 
On a normal Teletype machine, when  someone hits CR, the carriage will 
automatically come back but will not turn up  a new line.  This is a nice feature  
for RTTY Art but a real problem if you are trying to copy a weak signal and you 
 are already receiving partially garbled text. 
Fortunately, the Model 28 machines  can be easily converted to avoid 
overlining. This change requires no new parts  and can easily converted back to 
factory stock in a few minutes. 
Here are the steps to make the  change: 
    1.  Remove the roll of  paper 
    2.  With the motor running, look at  the top of the stunt box. 
    3.  Hit the CR key and some slot  will show activity.  This should  be 
slot 5, counting from right to left as you stand in front of the  machine. 
    4.  Hit the LF key and two slots  should show activity.  These  should be 
slots 38 and 40, counting from right to left as you stand in front  of the 
machine. 
    5.  Leave slot 40  alone. 
    6.  Remove the LP and take out the  stunt box (after disabling all 
power). 
    7.  Swap the universal code bars in  slots 5 and 38 and reassemble the 
machine.

Now, when the CR key is pressed,  nothing happens.  When the LF key is  
pressed, both CR and LF occur at the same time. 
You will still have to hit the CR  key when you are transmitting.  The  CR 
character still needs to be sent to the distant machine.  It may seem awkward to 
type the CR key  and have nothing happen. But, the simplicity of this change, 
the fact that no  additional parts are needed and that it works so well are 
huge  benefits. 
What is Automatic CR/LF? 
The first step is to check to see  that the “0” codebar is already 
installed.  Most, but not all, Model 28s have this feature installed.  You can easily 
check this by looking  under the left ribbon spool.  There  should be 9 code 
bars and the second from the bottom should be labeled “0”.    If it’s there -- 
fine.  If it’s not there, contact me for the  parts kit needed to add this 
feature. 
Next, look at the right side of the  line printer near the piston used to 
slow the carriage when CR is selected.  Look through the spacing drum – the  
round metal object that slowly turns as the carriage spaces across the  page.  
Using a lot of light, look at  the 12 o’clock position, through the top inside of 
 the spacing drum to see something that looks like a horse-head.  There could 
be something in the horse’s  mouth.  If it looks like a bit, then  you 
already have mod kit 157514 installed.  If not, you need mod kit 157514 installed. 
Next check to see if stunt box slots  4 and 39 contain parts.   You  can 
check this in the same way that you checked for motion when installing  
non-overline.  Remember, the slots  count from right to left when standing in front of 
the machine.  You probably don’t have anything in  these two slows and will 
need to obtain two uncoded function bars, part number  153440 and two sets of 
slot parts, part number 153916.. 
When you have the needed parts,  start the installation by adding mod kit 
157514 to the “horse’s  mouth”. 
The next step is to remove the stunt  box and add the parts to slots 4 and 
39.  Before you do this, you will need to code the uncoded code bar by  breaking 
off all of the tines except for one.   This is going to look like a very  
strange code bar when you are finished. The one tine that remains is in the zero  
level, non-selected position.  There  is a good picture of the function bars 
and how they are coded along with an  overview of the stunt box in the 
Teletype brochure that you can find at the www  dot rtty dot com website. This will 
take a while to download.  Page 12 of 20 has a good picture of the  code bars. 
If you don’t have access to this  document, break off all ten tines at the 
top of the code bar and three of the  four tines at the bottom of the code bar.  
The one tine that remains is in the upper right quadrant of the four  tines 
that are clustered together. 
Once you have the slot parts and the  code bar installed, and the stunt box 
and LP are all back in place, the checkout  is pretty easy.  First confirm that 
 spacing over to the extreme right hand margin causes an automatic CR and  
LF.  Then go back and count the  exact point when this occurs.  By  standard, 
you should get 73 characters on a line an automatic return on  character 74. If 
this is set correctly, you are finished.  
To adjust the return character,  locate the spacing drum and the five bolts 
holding the front and rear rings to  the spacing drum.  Going clockwise,  you 
will see that the first, third and fifth are all round-head bolts.  The second 
and fourth are hex-head  bolts.  You have to slightly loosen,  but not remove, 
the first, second, third and fifth bolts to adjust the right  hand margin 
adjustment. .Take a screwdriver and slightly move the rear ring that  is attached 
to the spacing drum.  Move the ring counterclockwise to lengthen the line 
length. You don’t  have to move the ring very far so go slowly.  Temporarily 
tighten the bolts that you  loosened and try the line length test until you get 
the desired line  length. 
73 
Russ WA3FRP