Transponder whine?

[imwithtuxedo]

Turned on my transponder today with engine off and it was making an audible whine when turned on. Not sure if I’ve turned it on without the engine running. Thoughts on the cause?

 

[NavAir]

Is the whine coming from the transponder itself, or is it electrical noise being picked up by the audio panel or one of the radios and heard through the speaker?

 

[imwithtuxedo]

Is the whine coming from the transponder itself, or is it electrical noise being picked up by the audio panel or one of the radios and heard through the speaker?

Transponder itself.

 

[Salty]

Turned on my transponder today with engine off and it was making an audible whine when turned on. Not sure if I’ve turned it on without the engine running. Thoughts on the cause?

I hear it, but it's difficult to hear over all the other racket.

 

[idahoflier]

Sounds like a noisy switching supply in the xpndr...

 

[Clip4]

Was that video made in 1990?

 

[Sinistar]

I think I just pulled out the same model this summer for ADSB. Make me a tempting offer. Its just sitting in a box....like about 9,000 other old transponders.

 

[imwithtuxedo]

I think I just pulled out the same model this summer for ADSB. Make me a tempting offer. Its just sitting in a box....like about 9,000 other old transponders.

I might hit you up on that.

 

[Doug Reid]

Are you sure your electric turn coordinator is not running ?

 

[weirdjim]

Where is the wife when this is going on?

Jim

 

[mkosmo]

Is there a fan in the transponder that may be causing it?