Electrophysiology, transmitter noise

1 post / 0 new
bendbir's picture
Electrophysiology, transmitter noise

 I'm trying to identify the source of a 7.63Hz click that is occuring in an electrophysiology set up I'm using.  The setup uses two filterless differential amplifiers who's outputs are transmitted as left/right audio using an A/V transmitter.  I've attached an image of the noise viewed in audacity.

Has anyone encountered this sort of noise before, or have any idea what may be causing it?