Thanks for the suggestions, everyone.toggle quoted messageShow quoted text
Vic, your issue sounds the most like mine of the things I haven't at least tenatively rulled out. I notice that I am confused, though. If the resistor wasn't adequate, shouldn't it go into ptt even without the mic like it would without the one for the key socket?
On Wednesday, September 25, 2019, Vic WA4THR via Groups.Io wrote:
On my V4 board there was enough drop when I plugged the mic in to cause the uBitX to cycle in and out of transmit. The internal Arduino resistor was not up to holding the 5v signal above the keying threshold, which I could monitor using the KD8CEC software. I added an external 5v dropping resistor and have had no issues since.
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