Re: Understanding Spurious Emissions

Howard Fidel

The overdrive occurs in the audio drive to the mixer.  There is no gain control for the microphone. I found on my board that the gain was too low. You can look at the mixer input with a scope and see when the audio starts clipping (I didn't validate this). Another test is if your audio reports are clean, you probably are okay, if you start to distort due to compression, you are over driving. I can't overdrive on my board because I put an AGC on the mic and its output swing is limited.

On 6/21/2018 9:59 AM, KE0GYC wrote:
Thanks for the concise explanation!

As for overdriving your audio, is this something that can be solved by dialing down RV1 to reasonable levels, or are the spurs created before that stage?

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