[GreenKeys] Model 28D typing unit question

[Don Robert House]

Nick,

The contacts and the springs with their associated tines are the  
horizontal tabulation kit that was added to the 28D
The 28D is the basic standard Bell System friction feed typing unit.  
The driving gearing should be for any of three
speeds with a 7.42 unit code.  Those being 60, 75, and 100 wpm.

I have forgotten what a 28A typing unit is used for.  In fact I don't  
remember working with a 28A.  We had 28D, 28E, 28L units.
in our shop.  Of course that was 1967 and a long time ago.

Someone else on here can probably tell you what the other gearing is  
for.

Nice to see your interest.

Old Don  K9TTY


On 19 Jan 2008, at 2:46 PM, Nick England wrote:

I am new to the mysterious ways of the Teletype and seeking
enlightenment ----

I have several Model 28 typing units on hand as I am in the process of
restoring a 28ASR.
One typing unit says "28D" and has differences that I am curious about
a) it has a different keyboard driving gear that won't mesh with my  
28KSR or
28ASR keyboard drive. Why this larger gear with more teeth?
b) On the right-hand (spacing) drum it has some tined keying mechanism  
(like
a security-light timer) that actuates switch contacts - Whazzat? I guess
some tab mechanism since the tines occur every 7 spaces?

photos at http://www.virhistory.com/ham/rtty-05.htm

cheers and thanks for all the great help you guys provide,
Nick KD4CPL
http://www.virhistory.com/ham/rtty.htm
---------------------------


_______________________________________________
GreenKeys mailing list
GreenKeys at mailman.qth.net
http://mailman.qth.net/mailman/listinfo/greenkeys