[GreenKeys] auto cr/lf

[Don Robert House]

Eugene,

Give the number to TELEMECHANICS in New Jersey.  Also the guy on our  
website that has lots of parts.  I can get one for you when I get to  
the museum, however I do not know when I will be there next.

Don

http://www.nadcomm.com (see the bottom of the home page for Teletype  
Supplies.)


On 21 Aug 2006, at 7:51 PM, Eugene Hertz wrote:

Wow! Thanks for the explanation. I will take some time to digest and  
poke around. Amazing, these machines are. Question on the  
overstrike.  Right now when I send a CR to the printer, the carriage  
returns but I do not automatically get a LF.  Does this mean that the  
art requiring overstrike will work properly? Your explanation seem to  
indicate that a CR sent to the printer should do nothing at all if I  
have that right.

On the auto CR/LF - this will take me some time to hash out.  I will  
probably set one of my machines (either the ASR or KSR) for this and  
leave the other with the auto so I can copy both.

Thanks again. I hope I can follow along!

While I have some folks attention, I am still looking for a little "h- 
shaped" lever that resets the reset bail on the 28ASR typing reperf.  
Part number is 159880. It is lifted by the cam on the K/KT/T knob.

Please let me know if you might have one of these.
thanks!
Eugene

-----Original Message-----
From: WA3FRP at aol.com [mailto:WA3FRP at aol.com]
Sent: Sunday, August 20, 2006 09:20 PM
To: ehertz at tcaf.org, greenkeys at mailman.qth.net
Subject: Re: [GreenKeys] auto cr/lf

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:

Remove the roll of paperWith the motor running, look at the top of  
the stunt box.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.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.Leave slot 40 alone.Remove the  
LP and take out the stunt box (after disabling all power).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








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