The Mystery has been solved.
I did not originally think the transistors used would be an issue but.............
The Wiki Schematic specifies a TIP47 and says 20-120VDC on the power supply.
I am using a US Teletype supply that puts out 120VDC
The Schematic in the PCB folder
https://github.com/fablab-wue/piTelex.s ... master/PCB
Specifies a TIP41C and just lists the power as VDD no voltage range.
I decided to look up the Datasheet specification of TIP41C and TIP47 and the solution was very very simple.
TIP41C is rated for 100VDC and TIP47 is rated for 250VDC. The T41C will not work with a 120VDC supply.
I removed the TIP47 from the Project board and put it in the pi-TW39 and now "It works"
So the TIP41C should only be used if the power supply puts out less than 100VDC and the side effect of pushing too much voltage thru is echoing in the line. Surprising that it didn't cook the TIP41C and that it somewhat worked.
JD
BjoernS hat geschrieben: ↑Do 21. Jul 2022, 17:18
Hi Joey
Before I forget you ...
JoeyD hat geschrieben: ↑Do 21. Jul 2022, 04:06
Who is the technical person for the Pi-Telex TW39?
Jochen (JKde) designed most if not all of the electronics available on the project page.
As much as I'd like to assist you in this matter, my electronics knowledge isn't deep enough yet, sorry.
I can help as soon as the signal touches the Pi's GPIO pins.
But some users here are very good with electronics, they may be able to assist you. It might make sense to open a separate thread for this.
Best regards
Björn
Dafür sind deine Bugreports und Tests viel zu nützlich. Von der Dokuarbeit ganz zu schweigen. (Achtung Schleimspur 
)
Habe nichts hinzuzufügen.
)