Vic, I seem to have found an old set of posts by you where you talked about your issue and fix. Did you end up disconnecting the built in pull up resistor? The value you quoted makes me think you added to it rather than replaced it.toggle quoted messageShow quoted text
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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