[arm-allstar] How to test / validate my USB sound fob signal

[Matt Rhoades]

Greetings Hamvoip wizards!

My node radio, a baofeng UV-82 (purchased from George G back in 2018)
recently quit working.

The symptoms were that I could TX into my node radio and it was received by
the node, but TX out of the node radio is not happening.

I think it was reasonable to assume that the TX of this radio after 2.8
years of constant use had just finally failed, also the node radio won't
even TX when I press the PTT on the radio.  So I ordered a new UV-82 and
un-soldered the old and connected all the conductors to a new UV-82.

Sadly the new radio exhibits the same issue :-( - this leads me to think
that there is some issue with the PTT signal from the fob to the node radio
- as such I'm seeking a procedure to verify that the sound card is
correctly generating the proper signals, voltages etc.


Is there a basis of what signals on what pins should be seen in certain
conditions?


I want to use a multi-meter to measure pins on the DB-9 in node tx mode,
what signals should I see?  I don't even know what pins are used to send
the PTT signal etc, is there any documentation on validating that your
sound card is putting out the correct signals that I could follow?