oscillation of recorded sound

Hi all!
I record my vinyl LP’s to Audacity then save them as mp3 files, BUT the sound oscillates in volume. I’ts kind of like the ocean waves…It drives me crazy to sit for a couple of hours and record only to have this crappy sound quality. How do I fix it?
Ichabod1

Do you hear the “oscillation” within Audacity or only after you export to MP3? What version of Audacity are you using, what computer and operating system, and what turntable?

– Bill

… and how is the turntable connected to your computer?