[GreenKeys] i-Telex, revisited...

[Jeffrey D Angus]

Two things about i-Telex.
1. The machines run at 50 Baud, i..e. 66 WPM.
     This why I'm working on an electronic dual speed control for my
     LO-15b. To switch back and forth from 60 to 66 WPM easily.
2. Now I'm NOT positive about this, but the TTY port on the TW39 card
     is set up to talk to what it expects for a machine on the line.

The Lorenz Lo-15b that I have, using the Lorenz dialer unit does some
things differently.
1. 5-7 mA idling current. i.e. On Hook, this lets the CO know that there
     is a machine at the far end.
2. When you hit the AT (call button) the line current jumps up to 40 Ma.
3. There is a short break signal, 20 mS,  at this point that unlocks the 
dial.
4. When the circuit to the other machine is completed, the CO switches
     (reverses) the line polarity. This closes the power relay to the TTY
     machine and entire machine starts up.
5. When the call is completed (disconnected) the CO switches the line
     polarity again, and the power relay turns the power to the machine
     off.

I'll have to ask Henning if that is how the TW39 port operates.

The reason I mention this is I'm not sure what the standard Western
Union was using when a machine was connected for TWX service.


-- 
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com