[GreenKeys] Are there any telephone switchers in the group?

[Chuck Rehor]

Brenda and team,
I am also VERY interested in all aspects of central telephone equipment
(wireline and wireless)!

I am very interested in designing and building a small 2-digit Step-By-Step
switch. Someday.

Another goal in life is to build a small 5ESS switch for analog, coin
phones and ISDN. I want to have my Model 33 be the ROP (Read-Only Printer)
like they were long ago. Unfortunetly I have not been able to get my 33 in
any kind of working condition at all.

If there is anyone in the Chicagoland area that would be willing to help me
with that part of my project, please let me know!!! I’m willing to pay!

Chuck
W9CFR

On Sun, Feb 16, 2025 at 8:52 AM Russ Miller <wa3frp at gmail.com> wrote:

> Since this is Greenkeys, I’ll branch off to the teleprinter exchanges that
> I worked on in the 1960s to 1980s.
>
> My first job,  after college,  was with Western Union Telegraph Company in
> Philadelphia where I was the engineer assigned to the Telex Exchange.
>
> I knew little about Central Office technology. All I had was an interest
> in Teletype machines and RTTY.  But, there I was, responsible for an ITT
> CSR-4 Telex Exchange.  The CSR stood for Circuit Switch Reed as the
> exchange, manufactured at ITT Milan, TN, used reed relays for the
> directional matrix. Imagine an entire floor of an office building filled by
> a Telex Exchange Central Office. Over 1200 direct subscribers using both
> polar and loop switching plus over 600 trunk circuits!  The clatter was
> similar to a number 5 crossbar machine but more compact. The Western Union
> Technical Review has an article about the CSR-4 in July 1966.
>
> 73
> Russ WA3FRP
> i-Telex 834328 WUTMPAM CHIL
> Sent from my iPhone
>
> On Feb 15, 2025, at 9:59 PM, Brenda Gentry via GreenKeys <
> greenkeys at mailman.qth.net> wrote:
>
> 
>
> Are there any greenkeyers who also take interest in telephone central
> office switching?
>
>   B. Gentry   KA2IVY
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> https://teletype.net/gksearch
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> >>> 1998-to-2001 greenkeys archive:
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