Tuesday, July 17, 2018

Cosmetic items added to ASR 33 and some work done on model 15 teletype


Today I drove up to visit RTTY Electronics, the world's largest business providing teletype parts, service and refurbished machines. I picked up the missing pieces for my ASR 33:
  • Local/Off/Line switch knob
  • Platen knob
  • Faceplate (Teletype logo)
All parts now installed, plus I have a spare rubber cap for the hammer that slams the type wheel against the paper.

The remaining part I need to finish the restoration is the 'arm with bushing' that snapped off. This part is used to adjust the spring tension that is applied to drive paper tape through the punch. I bought a spare perforator on eBay but won't have that until Thursday. 


I visited Marc's basement today for a short time and reinstalled the functional bail rod and related mechanisms into my printer. After making adjustments per the Teletype manual, it was time to remount the type carriage and make some tests. 

Hand rotating the mechanism while manipulating the state of the selector magnet armature allowed me to key in various codes, to verify whether each appears to work properly before running the machine under motor power. I tried these codes:

  • 01110 to encode the letter C
  • 01000 to encode a line feed
  • 00010 to encode a carrier return
  • 00100 to encode a space
  • 00000 to encode a chatter null

I did indeed fix the spacing clutch, so the carrier stays at its current position. What I discovered is that my main clutch that should be moving the function and print bails back and forth is not engaging. That means no printing, no chatter, no functions, just a quietly turning main shaft and the vanes trying to select characters based on the incoming code. 

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