Model 28 Teletype back in business

You can see a video of this machine working at Model 28 Typing (odysee.com)

This thing is quite complicated mechanically, and it took a bit of doing to find the manuals, find what manuals applied, how to find things in the manuals, then learn the terminology, and so on. The problem turned out to be a broken part that needed replaced. The broken part was responsible for resetting the keyboard after a key was pressed, so you could press a key once, then manually had to reset the code bars to press a key again.

Doing this required disassembling the major components, then disassembling the ‘signal generator’, which is the assembly attached to the large geared shaft

This assembly has a bunch of tiny parts and I am surprised I didn’t lose anything. Reassembly took quite a bit of fiddling with adjustments, fortunately the manuals run though these and I got a better understanding of what all this stuff does.

While I had it apart, I did disassemble the main drive gears to determine the speed of this machine. The nylon (ivory color) gear in the center is one gear that determines speed, but the part number isn’t visible when assembled. Disassembling this permitted me to pack the roller bearings with grease and find the part number – 195997 found in 573-116-800TC-iss3-7012. The speed of this machine is 100WPM.

Now that it is working mechanically, I can start trying to figure out how to interface this with a computer. 100WPM is not common on amateur radio, so getting this to work directly on the air wont be practical, but I can use it indirectly with fldigi and send text to it as a way to print text. This does get me interested in a machine that I can use directly on the air, maybe a Teletype Model 15 at some point.

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