[GreenKeys] [External] Just bought an Ebay ASR33 in the UK

[Jones, Douglas W]

From: ian parr <parrid at hotmail.com> -- Tuesday, February 4, 2025 11:29 AM
> I have finally managed to buy an ASR33 in the UK.
> It's in a bit of sorry state ...
> ...any suggestions or observations ...

It looks entirely reparable.  The one I fixed took more work:
-- https://homepage.cs.uiowa.edu/~dwjones/pdp8/UI-8/bugs.shtml#TTY33

Before you move it, beware:
a) Do not lift by the paper-tape reader or punch "outriggers."  These are fragile, not designed to carry the weight.  Lift by the front and back.
b) Do not tip on its back or side unless you install shipping screws and understand how to install them.
c) It is not hard to remove the top of the TTY from its pedestal.  4 screws that you access from below after removing the back of the pedestal.  Some TTYs have a power supply mounted in the pedestal.  This unplugs.
d) Once the top and pedestal are separated, the top would fit easily on a car seat, and aside from worrying about denting the metalwork, the pedestal is not delecate.

One of the annoying aspects of fixing these things is that Teletype Corporation liked using relatively obscure screws -- like 6-40 UNF.  6-32 UNC is common.  32 threads per inch.  6-40 is relatively rare, the same diameter, but 40 threads per inch.  This was no problem for the company, they made their own screws.  If you have the tools to make your own screws, it won't be a problem for you, but you can't buy these screws at the local discount store, they are relatively rare.

Many standard radio knobs will fit the line-local switch on the front.  The platten knob is harder, but there are people who've 3-D printed replacements.

You really can, with care and careful documentation, disassemble the thing almost all the way.  The worst part of reassembly is sticking all the springs back on their hooks.  I would avoid total disassembly, but if you break it down into large subassemblies, it is not difficult to clean, unstick, de-grease and re-lubricate the pieces.  I strongly recommend working incrementally, and make a point of labeling each part you remove.  I made a bunch of light cardboard tags that I tied with string to parts, so I could remember the order they were removed in and from where.  References page numbers and drawings in the manual are a useful way to work the labels.

If you have to remove the keyboard, bind the end plates to the sides with a few wraps of wire so they don't spring loose.  If you do let them get loose, reassembly is difficult (far from impossible, I had to do this to replace keycaps and one of the encoder blocks.)

                Doug Jones