garmin 530 + noise

[lbgjb]

all of a sudden noticing a once a second noise that 'disappears' when using radio, listening to music, or using intercom. turned everything off one at a time, and noticed the noise go away when the 530 turned off. came back on when turned on. it syncs with the clock on the 530--once per second. any thoughts on how to get rid of this annoying noise. larry

[sonny junell]

I had a similar problem with a KX-155 in my 172, And come to find out it was the transponder, i noticed it was in sync with the reply/interrogation light, I never fixed it, I didn't have the money! But my avionics guy told me to start with the anttena.

Good luck

[Sticky1]

The audio jacks should be isolated from ground.....(using the garmin audio panel)