RF since connecting audio

[AlanR]

Hi
When I first installed my twin Skyviews I didn't connect the audio wiring for whatever reason and the comm, a Trig TY91 worked fine with no RF or anything like that.
I have now wired both Skyviews to the Trig TY91 and receive the audio warnings and messages all fine except that I now get an occasional and annoying 'Whoop, whoop' sound through my headset. I don't get it all the time, nothing in the cruise or normal flight but for some strange reason I hear it mainly when I am in the pattern and about to land.
I have grounded each Skyview unit casing.

All ideas to solve this much appreciated.

Alan.

 

[Dynon]

Does it sound like an alert? Or some kind of interference? We have the AOA tones, but they're more like beeps, not whoops. Most everything else is voice. If you export your user data logs, there now a separate alert log that can help you figure out what any quick self-clearing alerts might be if they're generic and you don't have a chance to see it before it auto-clears.

 

[AlanR]

No I think it it is interference of some kind. It doesn't seem like an alert or the AOA.....it is just two 'whoop whoops' and then silence and then again 'whoop whoop' a few minutes later
Sometimes it is very faint and other times it is quite loud. I have found that if I recycle the avionics master it gets rid of it for a while then it comes back.
It has only started though since I wired the audible warnings to the Skyviews.
I am at a loss at the moment.....

 

[JTD]

Had it happen to me today. Was working on a engine problem and had run the backup battery down by accident. When I would turn on avionics master I would get a whoop whoop sound in the headset. Thought it was a ELT at first.   Shut everything off and pulled both com circuit breakers. Avionics master back on and got the whoop whoop again. Only lasted three whoops. It had to come from Skyview audio as nothing else is connected.  I think it might be related to a low battery and a battery condition fault.

 

[AlanR]

Hi Tim,
No help I know but at least somone else is getting it and not just me. The noise has to be from the Skyview audio, but what is causing it is the mystery.

Hmmm...Backup battery fault?..Do you think?.... Mine is a fairly recent twin Skyview installation and I haven't got around to carrying out the full backup battery test yet. I don't get a battery fault icon showing so I don't believe it is run down or flat, although I do get the caution warning that a battery test is needed at some point. Would this cause a 'whoop, whoop' though?...I can't see anything in the manual that says so.

 

[jakej]

Simple check - unplug the battery

 

[AlanR]

Yes, thanks, disconnect the battery maybe is the next step if that is the only lead on the problem I have. A bit of a pain to get at it on my installation though.

 

[preid]

Do you have two screens? one has battery the other not? if "yes" turn off the one with the battery attached and see if it does it with the powered (non battery backup) screen. Thats assuming that both screens have audio connected of course

 

[Dynon]

Any chance you can record it? Maybe hold up your phone mic to your headset to capture the audio in a video? Other than AOA, I think the basically every other alert is words. And AOA is more of a beeping/geiger counter sound and not really anything I'd describe as a whoop.

 

[AlanR]

Do you have two screens? one has battery the other not? if "yes" turn off the one with the battery attached and see if it does it with the powered (non battery backup) screen. Thats assuming that both screens have audio connected of course 

Yes that is the setup one with battery and one without and both have audio...Good thought, thanks, that is easier than struggling to disconnect and then reconnect the backup battery.
I will try that...

 

[AlanR]

Any chance you can record it? Maybe hold up your phone mic to your headset to capture the audio in a video? Other than AOA, I think the basically every other alert is words. And AOA is more of a beeping/geiger counter sound and not really anything I'd describe as a whoop.

Thanks for the idea.... I can try I suppose if all else fails but may be a bit difficult to do due to the noise being intermittent.

 

[c4c]

Strobes?

 

[AlanR]

Strobes?

No strobes was my first thought when this happened but with them turned off I still got it.
The strange thing is I did two one hour flights on Wednesday and I didn't get the 'whoop, whoop' at all..not even once and I haven't changed anything at all! As I said previously it is so intermittent. Another day it seems it will do it all the time...I just don't get it.

 

[Pilotlight11]

I have experienced what I think is the same thing. Next time you hear it, switch your transponder to standby. When i first experience it I learned by accident that flip/flopping the freq and then going back to the original would stop the noise (which I actually described as - like the interference one gets from a rotating beacon when your alternator is dead and your battery is low). I've posted another thread about a popping noise created by the 261 in my headset. There may or may not be a connection, but switching to standby fixes that noise - and obviously is not a viable solution.

 

[AlanR]

I have experienced what I think is the same thing. Next time you hear it, switch your transponder to standby.  When i first experience it I learned by accident that flip/flopping the freq and then going back to the original would stop the noise (which I actually described as - like the interference one gets from a rotating beacon when your alternator is dead and your battery is low).  I've posted another thread about a popping noise created by the 261 in my headset.  There may or may not be a connection, but switching to standby fixes that noise - and obviously is not a viable solution.

Ok thanks for the train of thought.An avionics guy has also suggested transponder. If I can pinpoint it I can then work on a solution afterwards.
The thing that gets me though is I didn't have this until I connected up the Skyview audio!

 

[AlanR]

Well I tried switching off the Skyview that has the backup battery connected to it......still got the 'whoop, whoop'.
Tried turning the transponder off....still got the 'whoop, whoop'.
Not all the time I might add, just occasionally.
I am now thinking of 'ground loop' from the ground wires which I connected to the Skyview cases when I wired the audio.
Any other suggestions, ideas/theories that anyone has would be gratefully appreciated and taken on board.

Alan

 

[Dynon]

Are any visible alerts firing when you hear the sound? You can also export your user data logs and check the alert log to see if anything is listed there at those times.

 

[AlanR]

No I have no visible alerts when I hear the sound.

I will need check up on how to export user data logs and check the alert log. Unsure how to do that without reading up on it.

 

[jakej]

AlanR

I could try troubleshooting this issue with you offline if you wish, just pm me.