Strange Noise in Headsets

[woneill]

Following the assumption that anything's possible (could it be the SV700/PM3000) and a bunch of very smart aviators hang out hear, let me ask if anyone has any ideas for me to try.

- Plane is a CTLS with SV700s + PM3000 intercomm.

- Noise sounds like a buzz. Not static. Both headsets.

- Starts off intermittent on departure climb with full power - almost thought it was Morse Code VOR id at first.

- Becomes more constant the further from airport I go. AND departure control gets increasing harder to hear.

- 15 miles out I completely lose ability to hear departure over the noise nor can they hear me. I turn back.

- Pick them up again in 2 miles.

- Approaching airport the noise subsides but doesn't disappear and voices return much as with departure sequence.

- Reducing power from WOT to 4800RPM also noticeably reduces noise.

- On the ground the noise is gone.

- The above has happened on the last 2 flights.

- So, near the airport, communication with tower & departure is possible. The noise is just very annoying.

- The noise finally overcomes the ability to communicate around 15nm out.

The plane is always hangared and no mx or changes (except updating SKYVIEW databases) since the issue began.

Any thoughts or ideas welcome.

 

[dynonsupport]

Does the volume of the buzz change when you change the volume on your radio?

 

[woneill]

I didn't try volume.

Squelch has no effect.

 

[jakej]

Won

What I'd do first to eliminate causes is 1. unplug both headsets and use only one then try another one - who knows it could be one bad mic?
2. Turn everything else off except radio & SV's, PM3000 too as it should default to com 1. 
3. Go fly, then turn on avionics one at a time to see if one of then is creating the problems, who knows something obviously has changed and a connection may have broken etc.
Good luck, these sorts of issues can be a pita to sort out.

HTH

Jake J

 

[preid]

Won;
I'll support JakeJ #1- I have two expensive ANR headsets and I heard clicking sounds when in the air but not the ground, near the airport (tower) I would get a thump.. thump, probably like your Morse code. Everything was resolved except for the morse code near the tower (3-7 miles out) the volume remains the same except when I would transmit- Replaced the headset and all but the morse code has disappeared. But that is only at one frequency so I can live with it.
I can see if maybe the firmware 3.3 did something but not the database, unless that is what you meant. I can see the firmware because there may be some interconnectivity issue with the new Audio feature, although doubtful but possible.
Grab a different headset and fly around the pattern, hopefully that will be better, I feel for you on this!

 

[airguy]

Cellphone turned on?

I can hear my cellphone transmitting through my Bose X's if I forget to turn it off, the data packet pulses could be mistaken for a Morse-Code like sound.