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Soft ticking noise

J

jjhoneck

Well Known Member
On our last few flights, before start up and after shut down, we have been able to hear a soft, cyclical ticking sound in our ANR headsets.

It is cycling at about one tick every 1.3 seconds, give or take. It is very soft, and cannot be heard without headsets on or when the engine is running.

I've tried turning everything off (strobes, radios, etc.) and it is still present. We did not notice this until the last few flights.

The last thing I did to the plane was to install a Commitlift high output dual USB port in the back cockpit. We did not hear the ticking sound before this addition. The port is working fine, it's doing a great job keeping our tablet and phones juiced up in flight, and seems like an unlikely source, but who knows?

Any theories?
 
Simple check would be to remove power from the USB hub. The polling rate for USB is much higher than 1.3 seconds but you never know...
 
I get a little clock tick from my Dynon D180 and from the Gns430. Can't hear it with the engine running.

Something to look at...

Don
 
A memorable flight included some ticking in the headset. I was approaching the Olympics opening ceremony at Salt Lake. Turned to see F16's missiles locked. ATC said turn right a little. Jet core was pushing me at 350knots ground speed. I went around to the right as advised. George B. was happy watching soccer in the stands. Glad the Lightspeeds are sensitive to that RF frequency...
Later, I had Customs tell me they plotted my course from the moment I lifted of Boise that evening. They had a borrowed AWACS up high. I just love technology inflight.
 
Are you anywhere near a radar? Either ATC or weather. I have noted some ANR headsets will give a slight click or chirp as the radar beam sweeps past.
 
AFS

Jay I have the same thing on my AFS3500. It appears to be the clock. I was sitting there after shutdown writing down my Hobb and Tach numbers and noticed a very faint tick. Thought about as nothing was on but the EFIS. As I was thinking and looking at the screen I noticed the tick matched the seconds clicking off on the clock in the upper left corner.
 
GrayHawk said:
Are you hearing any 'tocks' or is it just 'ticks'? :)
Click to expand...

lol!

Last night we heard a little buzzing sound momentarily, too. Unlike the clock tick sound, it was seemingly random.

Since I just ran a power wire back to the USB charging ports, and that wire runs alongside the wires leading to my headphone jacks, and the USB port itself is adjacent to both headphone jacks, I'm going to try pulling the power to the port (as someone upstream suggested) to see if it goes away.

The sounds are not audible in flight, so it's not a huge deal. Mostly I'm just curious why it would be so perfectly cyclical.
 
jjhoneck said:
lol!

Last night we heard a little buzzing sound momentarily, too. Unlike the clock tick sound, it was seemingly random.

Since I just ran a power wire back to the USB charging ports, and that wire runs alongside the wires leading to my headphone jacks, and the USB port itself is adjacent to both headphone jacks, I'm going to try pulling the power to the port (as someone upstream suggested) to see if it goes away.

The sounds are not audible in flight, so it's not a huge deal. Mostly I'm just curious why it would be so perfectly cyclical.
Click to expand...

I had a similar issue with my headset. Eventually, i unplugged the headset and the noise was still there. It turns out that a mode s- es transponder puts out more rf than my old mode-c. This was picked up by the headset cables and demodulated by the unpowered electronics in the headset. Apparently Cirrus has this problem and the headset manufacturers are dealing with it.
 
flightlogic said:
Sam, the chirp is a really fast sweep when it emanates from a sidewinder missile.
Click to expand...

Actually, unless things have changed recently, Sidewinders are heat seekers. They don't emit a signal outside the missile or the fighter carrying it.
 
Last edited:
Pete, I was waiting for someone to catch that...
You get the award for up earliest and careful reader.
In truth, I never saw Torch 52. Torch 51 was on VHF, same as me.
I could see him at my 8 o:clock. I am presuming the missile lock sound in my Chinese Lightspeed headsets was from Torch 52 at my six. Anyway, I was dumb enough to think it was all pretty exciting. That 421 Cessna would have been easy to hit.
Back to the thread.... lots of noises with a repetitive nature are capable of getting into our noise cancelling headsets these days. We are indeed flying with lots of RF and digital signals onboard. The cool part is that it is self correcting. As you age, you won't hear it anymore.
 
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