There's also a schematic for the TELEX polar adapter (thanks to Don House)
Hi Dennis,
I'll forward you a copy of the schematic directly to your email address. I don't think that GREENKEYS will allow me to send this schematic as an attachment.
First of all the Telex service was 50 baud as opposed to Amateur Radio RTTY which is 45.45 Baud.
Second, the keyboard is slightly different. An Amateur Radio RTTY machine used uppercase S as BELL while you will see that your Telex machine used uppercase J as BELL. Uppercase D on an Amateur Radio RTTY machine is $ while a Telex machine uses uppercase D as the WRU or request for answerback.
Third, the Telex service had two different ways to connect a Telex machine to the Telex exchange. The first was loop or local which was 60 ma. This would match the interface provided by the standard RTTY converter such as the HAL ST-6 where the power to supply the loop current comes from the RTTY Converter. But there was a second mode called polar or Long Distance (LD) that operates at 35 MA, ground return. You will need to see if there is a polar adapter in your Telex machine. If yes, you need to remove it.
An alternative to converting your Telex machine to Amateur Radio RTTY operation is to join the i-Telex network. Here is a link to information about this worldwide network of individuals using old Telex machines and communicating via the Internet.
https://www.i-telex.net/
73
Russ WA3FRP
Telex 834-328 WUTMPAM CHIL
On Mon, Jul 13, 2026 at 6:44 PM Dennis Kwasny via GreenKeys <
[email protected]> wrote:
>
Hello to all,
I acquired a model 32 ASR that was used in western union telex service. I would like to try to restore and use it for amateur radio RTTY. The motor runs but I believe the call control unit is not operational and there does not appear to be any loop current to the selector magnets so the keyboard is not functioning at this time.
I have tried to locate schematics (Navy Radio site) for the machine, but to no avail. Paul Cembura (Mr. Teletype) has told me that these machines were proprietary to western union so there isn’t any schematic information from teletype corp.
My questions are:
Does anyone have schematics or wiring diagrams for a western union model 32 they would be willing to share?
Does anyone know what speed and baud rate the machine might have operated at when it was used by western union?
Appreciate any help in advance.
Dennis
WA8ZRK
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