Dennis Yancey asked the group “Has anyone used a dynamic mic on the uBITx?” Dave WI6R responded with a guide for modifying the uBITx to use a Dynamic Mic:
Substituting a Dynamic Mic
Replacing R63 with a Zero Ohm resistor and putting a 10K potentiometer at the Mic input should allow a Dynamic Mic to work now with a Mic Gain Control. Also, R60 that supplies Mic BIAS to the Electret-Condenser Mic needs to be removed. If there is not enough gain after this mod, you might have to reduce the value of R64 to maybe 470 Ohms or so.
If you cannot look at your transmitted signal on a scope at least listen to your audio on another receiver to verify you are not causing distortion.