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Re: sBitx Mic input - assist request

 

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QD1 is toast, the base to emitter voltage is too high!

Recheck and if you find Voltage between base-emitter is much more that say 0.7 volts then replace the transistor and you audio will be back.

Raj, vu2zap

On 09/03/2025 9:32 PM, WF4RC Carroll via groups.io wrote:

I have a new sBitxV3 board only. Everything is working except the Mic input. I started experimenting with some microphone I had and the recorded transmission has lots of noise and very low audio. I measure 2.1v on mic input tip. I think it should be 5v. Can anyone guide me as to what the issue may be and where I should look. Here are my measurements/ calculations.?
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