[GreenKeys] M 32 & i-Telex

[Russ Miller]

I believe that the Line Interface Box provided a loopback capability that
was used in testing from the central office to confirm that the leased line
was operational.

The terminal adapter TLX-1 converted the two tone signals (called F1-F2
inside Western Union) on the leased line TLX-1 to DC signalling.

A little background...

Starting in the late 1950s, loop signaling was offered in two different
configurations for Western Union Telex in the United States. The first
option, sometimes called local or loop service, provided a 60 milliampere
loop circuit from the exchange to the customer teleprinter. The second
option, sometimes called long distance or polar, was used when a 60
milliampere connection could not be achieved, provided a ground return
polar circuit using 35 milliamperes on separate send and receive wires.

By the 1970s, under pressure from the Bell operating companies wanting to
modernize their cable plant and lower the adjacent circuit noise that these
telex circuits sometimes caused, Western Union migrated customers to a
third option called F1-F2. This F1-F2 option replaced the DC voltage of the
local and long distance options with modems at the exchange and
subscriber ends of the Telex circuit. This is where the TLX-1 was used.

Russ WA3FRP
i-Telex 834328 WUTMPAM CHIL

On Thu, Apr 15, 2021 at 11:22 PM Yahoo <j-mcclurg at sbcglobal.net> wrote:

> Well I got the 32 home and am now trying to get the thing cleaned up!!
>
> One thing I am NEEDING is the Print Hammer Head,  I have gotten a couple
> of ideas from others but would like to find one.
>
> I think that some one made up some awhile back but do not have any info on
> who it was.  If someone does know/is that person can you please drop me a
> line one one??
>
> I will have the machine out cleaning Friday and will post some pictures of
> what I have.
>
> The Pedestal  contained two boxes, one is a Line Interface Box Model
> 13551-B w/a manual (!) in the lid dated May 1980!!  The other is a Terminal
> Adapter TLX-1.  Both from Western Union.
>
> If anyone has any ideas on what/how they were used I would like to know
> just to see how they "Did it in the Day"...
>
> Looking to find/get/order a set of Cards for a i-Telex, Does anyone know
> if there is a set here in the States that need a good home??  I can order
> them from Germany but the wait time is out of site for shipping............
>
> Thanks,
>
> Chuck
> N7UVZ
> HH 11998
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