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If the sine wave isn't pretty???

Posted by TomWh on March 14, 2017 at 11:29:41:

Well maybe Michael will kick in? Well we know one thing for sure pretty sign waves are not on that scope.

OK I got the new scope to check phase angles on some motor controllers I have been building. So I decided to go after some hum on the phono stage. So I hooked up the scope to the right channel output before the avc. Not sure where I should be testing and what that picture tells us. Also the fluke 87 give about 23mv RMS and the scope is 150 pp those numbers do not equal after doing the math.

I have done very little scope work in the past. So anyone who wants to give me a step by step lesson on where they would check and what it should or should not look like I would be great full. Hum is a tricky thing.

Thanks Tom