[GreenKeys] Model 28D typing unit question

[Nick England]

Many thanks to you, Jim and also to Don, Rice, and Larry - I hope this has
just been some idle fun on Saturday for you guys - I am enjoying learning
about these machines and continue to be in awe of the engineers who designed
such mechanical marvels.

I now understand that this 28D typing must have been set up for 7.0 unit
service in a KSR or ASR where the keyboard had the 163519  keyboard
drive/clutch shaft instead of the usual 154032. Now I know what to look for,
I'll try not to scratch my head so much the next time a typing unit won't
fit into my 28ASR.

Many thanks, guys - what a wonderful crew!
cheers,
Nick KD4CPL
---------------------------

----- Original Message ----- 
From: <jhhaynes at earthlink.net>
To: "Nick England" <nick at 3rdtech.com>
Cc: <greenKeys at mailman.qth.net>
Sent: Saturday, January 19, 2008 6:22 PM
Subject: Re: [GreenKeys] Model 28D typing unit question


>
>
> On Sat, 19 Jan 2008, Nick England wrote:
>
> > Anyway - 28D mystery keyboard driving gear looks like163503
> >                28A standard keyboard driving gear is 150441 (which
matches
> > all the manuals I have)
>
> I'm looking at 573-115-800TC Issue 3 May 1969.  It says
> 150441 is for 7.42 and 11.0 unit code
> 163503 is for 7.00 unit code, 50/75 Baud
> 178764 is for 7.00, 7.50 unit code
>
> On the keyboard the driving gear is part of the same piece that has the
> clutch.  The normal one i(Mark II) seems to be 151154  There is a 163519
> that is part of a mod kit (320236) to modify keyboard with distributor
> from 7.42 code to 7.00 unit code operating at 8.05 [sic] Baud.  Then on
> another page for Signal Generator Shaft Mechanism Mark III it says
> 154032 for 7.42 unit code, 163519 for 7.00 unit code, and 178787 for
> 7.50 unit code.
>
> What I can't explain is why any code other than 7.42 would be used on
> a Bell System unit.
>
> I didn't really get the picture where you are talking about contacts
> on the spacing drum associated with tab stops.  However it was normal
> in an ASR or a printer associated with tape sending to have contacts
> on the tab mechanism in the printer.  This was to open the circuit to
> the feed magnet on the tape reader so as to stop the tape reader long
> enough for the tab operation to complete before reading the next
> character from tape.  What a kluge!
>
>
>