[GreenKeys] Is this a typo?

[w9ddd at tapr.org]

Hmm, I didn't scroll down to see if they listed pull bar versions for switch operation.  I did note that the charts list the pallet p/n, the pallet/pull bar assy and just the pull bar. So perhaps that's how you get the pull bar numbers for the selector.  

FRXD I had had some pull bar switches, but I never paid attention to the fact that the reader had multiple contacts in each of the five switch stacks which were wired up to decode certain charters.  

The LRXD (commonly called RT set) had a set of external relays that performed the same functions as the FRXD reader when used as a replacement for the FRXD.

John, W9DDD


> On Jun 12, 2021, at 11:42 PM, Jim Haynes <jhhaynes at earthlink.net> wrote:
> 
> I have never seen one, nor even a picture of one, but I have a good
> guess what a Model 14 non-typing selector is.  I'm guessing it is like
> a Model 14 printer but with switch contacts mounted above the ends of
> the pull bars so that a contact closes when a particular character
> is received.  This would be a forerunner of the SOTUS, lacking the
> ability to detect character sequences but that could be done by relays
> outside the unit.
> 
> In Western Union Plan 21-A the "way" operating table had a 2B printer
> with contacts above the pull bars.  "way" means a multistation line
> with the ability to poll the stations for traffic and to blind stations
> from receiving traffic not intended for them.  In this system the
> printer also served to print the messages, but the pullbar contacts
> were used to control polling and print blinding.  Relays in the table
> detected the character sequences used for these control functions.
> 
> Also you will sometimes see pictures of the FRXD machines with pullbar
> contacts.
> 
> It seems like a simple thing to just mount contacts where the pull bars
> can operate them.  But for some reason Walt Zenner got a patent on a
> special pull bar, hook shaped, for this purpose. patent 2,323,438
> of 1943.  Supposed to provide quick action of the switch, and to not
> load the pull bars.
> 
>    ---
> 
>    "Ya can argue all ya wanna, but it's dif'rent than it was."
>    "No it ain't! No it ain't!  But ya gotta know the territory."
>        Meredith Willson, The Music Man