Having issues interfacing mtr2000 to a cm108 fob.
Using B4 cos line ,the MTR will Ptt but no rx indication.
If I remove the cos line off the MTR and fake the cos line to the fob,it works. Using the MARTI port ,unit has no wireline card.
Thought about isolating the B4 with a 4n32 optical device.
Any thoughts?
Bruce
Ve3bv
I think it is wise to buffer the in/out of the sound fob no matter what.
OPTO-ISOLATE if you really fee the need. I do on PC using the parallel port just because it takes so little to booger the computer up or even toast it through that port.
But my guess is that the voltage is not within threshold values from current sinking in active circuit so buffering it some way, even with a 2n2222/3904/3906 should be enough.