I can offer something on this...
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On 21-Feb-03 at 13:28 Eric Smith wrote:
>George writes:
>> Hi, I have just bought a nice clean TELEX machine, it's a TTY-32,
>> 5-level coding,
>> with what looks like a phone line hookup, dial-type phone.
>>
>> I wonder if anybody knows what the modem standard is for this, and/or
>> any phone number I could call to test this thingy out!
Now I'm glad I spent those years with Western Union's Field Service division (when they still had one), fixing those things.
The Model 32 Telex machine did not operate on a standard phone line. It required a dedicated hookup to a specially-equipped Western Union central office. The normal interface was high-voltage DC, 60mA current loop. In the case of longer-than-typical cable pair length, a polar adapter was employed to create a differential DC interface.
The later Model 32's were equipped with TLA's (Telex Line Adapters) which used FSK, as you've already guessed. I don't recall the frequencies involved exactly, but 2200/2000Hz Mark/Space wants to stick in my head for some reason.
The Telex network, as far as I know, is long dead in the United States, and some other of the more industrialized countries, replaced pretty much by the Internet and FAXes. The Telex-ready Model 32's ran at around 67WPM (Words per Minute)/50 baud. Amateur Radio RTTY standard calls for 60WPM/45.5 baud.
In other words, you've got yourself a true museum piece there. You may be able to, if you wanted, convert it for ham radio use. However, you would need to change the motor gearing to bring the speed down a notch. Finding the necessary gear would be an adventure at best, though I can suggest a couple of possible sources if you want to try this.
Enjoy!
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies --
http://www.bluefeathertech.com
ARS KC7GR (Formerly WD6EOS) since 12-77 -- kyrrin_at_bluefeathertech.com
"I'll get a life when someone demonstrates that it would be superior
to what I have now..." (Taki Kogoma, aka Gym Z. Quirk)
Received on Sat Feb 22 2003 - 08:48:00 GMT