Czechoslovak T100 too high loop current

Karski99 · #1

Hello, I am a novice when it comes to teleprinters, I recently purchased a t100 produced in Czechoslovakia under a Siemens license. I would like to connect it to the i-telex network and have it work with the tgs-1 dudek encryption machine. After connecting to the encryption machine, the indicator on it went off the scale, so I checked the current in the loop with a multimeter and it was 68.7 mA. The voltage across capacitor c1 (replaced) is 72V. I also checked the resistors and all except the one I replaced 39k, are correct. I would be very grateful if you could help me regulate the current in the loop. Best regards.

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#2

Hello Karski99,

welcome here at the forum and teleprinter enthusiasts. Do you have a name, how we can call you?

Please give us a bit more details about your setup to get a better understanding of your situation. How do you provide your line current?
I don’t know anything about your encryption unit. I would also recommend to use your equipment without encryption unit in the first step. After your teleprinter is running well you can install your encryption unit.

General info: Usually the line current will be adjusted with a serial resistor. E.g. at the i-Telex TW39 card there is a 1,2 k resistor (if I remember right). Maybe you can provide a sketch of your setup.

Karski99 · #3

Good evening sir, thank you very much for your answer, my name is Maciej Piekarski. It is highly probable that I made a mistake, that the teletypewriter is damaged, most likely the problem lies with the encryption machine (probably bad connection, damaged resistor, or lack of support for FSG), a novice's error. You are right that I should first check communication with another device. The parts to build a communication interface with the computer will arrive on Monday, then I will check carefully whether the teletype is working. Kind regards Maciej.

#4

Hello Maciej,

I hope it’s okay to call you with your first name only. (We are not very formal here.) Don’t worry only people which don’t work make no mistakes.

There are only a few people in the forum using a Zbrojovka T100 but basically it’s the same like the Siemens T100, at least the mechanical part. As I heard the electric parts were replaced by cheaper ones and prone to fail.

I guess you are from Poland and I’m not sure if you can read the German articles but I hope Google Translate can help you to find information about your teleprinter. If you need something, please let us know. I guess you have found the manual?

In the first step I would recommend to check if the machine is running in local mode. Later you can try to run it with external line e.g. i-Telex, Pi-Telex, ...

#5

Hello Maciej,
welcome to the forum.
Mostly bad relay contacts and broken coils cause problems with the Czech machines. They are of poor quality compared to the
original German made control units.
Do you have the schematic of the control unit?
Please read this thread: https://telexforum.de/viewtopic.php?t=3 ... o&start=10

There you can find also the schematic for the dialler unit (FSG NL).

Good luck!

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