[GreenKeys] Model 28D typing unit question

[Nick England]

Hi Larry - I think I understand about different speed gearsets coupling the
motor shaft to the typing unit, but that's not what is bugging me.

This mystery gear goes from the typing unit to the keyboard - why would the
keyboard run at a different speed than the typing unit??? And what model
keyboard shaft meshes with this mystery gear??
Anyway - 28D mystery keyboard driving gear looks like163503
                28A standard keyboard driving gear is 150441 (which matches
all the manuals I have)

Both of these are phenolic gears located on the typing unit main shaft and
are supposed to mesh with the keyboard signal generator drive shaft (154032
I think).

cheers,
Nick, still mystified

----- Original Message ----- 
From: "Larry Tighe" <larryradio at worldnet.att.net>
To: "Nick England" <nick at 3rdtech.com>
Sent: Saturday, January 19, 2008 4:07 PM
Subject: Re: [GreenKeys] Model 28D typing unit question


> Different gears for different speeds.  I think there were different gears
of
> "plastic" for a given speed that would not mesh with the steel
> equivilents.....
>
> The motor and the driveshafts had to have matching sets for a given speed.
> Can you get the numbers off of the gear and let us know??
>
> lar
> ----- Original Message ----- 
> From: "Nick England" <nick at 3rdtech.com>
> To: <greenKeys at mailman.qth.net>
> Sent: Saturday, January 19, 2008 15:46
> Subject: [GreenKeys] Model 28D typing unit question
>
>
> >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
> > ---------------------------
> >
> >
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>