Identify active transducer - on the hard

[meridian28]

Is there a way to identify a working depth transducer when out of the water?

[double u]

usually you can feel the pulses when u put your hand on them & hear a faint "ticking"

[clownfishsydney]

I read the other day if you put petroleum jelly on the sounder it will work out of water. Have not tried it yet to see if it works.