[GreenKeys] Repair help on ATD-233 (model 33 ASR) [Richard Barrow]

[Richard Barrow]

Thank you guys so much for the assistance. The training manual I've found
on the retrowagon as well as Curious Marc's videos has been instrumental to
furthering my understanding of this machine, I appreciate the references.
This machine is an ASR and as a result there is chaff everywhere in the
machine. There is a bit bucket that seems to work surprisingly well built
into the carrying caddy.

The first problem I intend to troubleshoot is the output of random
characters while in Local mode the selector coil seems to vibrate when the
switch is both in the off and local position. I haven't put an
oscilloscope on it but It sounds like a 60hz square wave leading me to
believe It may be a filtering issue in the power supply. In line mode it
seems to be working, running open when the modem is unplugged and remaining
silent when plugged in and the distributor actuating for one cycle when I
type a key. I will have to consult the wiring diagrams and test the outputs
on an oscilloscope.

I was planning on buying the serial converter from DeRamp as I have bought
a few other of his products and I'm very happy with them.

Will the shipping screws impede the operation of the printer mechanism?

On Mon, Jan 30, 2023 at 11:30 AM WAYNE <teletypeparts at comcast.net> wrote:

> Richard,
>
> Welcome to the group!
>
> Curious Marc is a good site to watch.  He goes into great detail.
>
> Another site is the wiki site set up by Jeff Albrecht for me and new
> owners.
>
> https://wiki.theretrowagon.com/wiki/Teletype_Model_33
>
> Less detail than Marc's but some helps.
>
> Main thing to remember is most 33 issues can be found by VISUAL means.  A
> lot of looking.  Congealed grease and oil is common in machines not run in
> a long time.
>
> Dont take the keyboard apart!
>
> Some pics of your machine might help.  I am guessing its a KSR, no tape
> punch or tape reader.
>
> Also if its portable the printer is likely held in by its shipping
> screws.  Normally the printer is help in by gravity alone.  It sits in 4
> rubber mounts.
>
> Send some pics and make no adjustments.
>
> 73,
>
> Wayne
> KB1FDW
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20230130/7e8da903/attachment.html>