Sidetone > 0 results in beacon/strobe noise

[CGameProgrammer]

This may not be a Dynon issue, but I've always had beacon and strobe noise coming through the radio; they both occur even with the intercom off. However yesterday I discovered that if I set sidetone volume to 0% then they go away completely. Of course that also means I have no sidetone when transmitting.

Is there a way to remedy this? I hate the beeps/clicks but I would like to retain sidetone.

To reiterate, this occurs even with the intercom off or with intercom squelch up to max. It's not an intercom issue.

 

[rvator51]

These are normally caused by ground loops. I would investigate how everything is grounded and see if I could fix them to eliminate this issue.

 

[kurtfly]

CGameProgrammer,
What kinda plane is this - Metal or Composite? If it is metal you should make sure your Mic and Headset jacks are isolated from airframe ground. They make nylon washers that keep the Mic and headset ground from contacting the airframe ground. If you do not have these you can temporary remove from panel and leave hanging, not touching the airframe.

Kurt

 

[CGameProgrammer]

It's a stainless steel frame and the jacks are mounted to a metal plate but they are using the supplied nylon insert and washer so they shouldn't be contacting the metal, but I can try removing the jacks from the mount and seeing if it makes a difference. Good idea.

 

[mmarien]

I have a composite plane and had the strobe noise in the headset. It wasn't loud but it was there. It's probably introduced through the radio antenna. My strobe power supply sat within a few feet of my radio antenna. I believe they now place the strobe power boxes out in the wing tip because of that problem. Another solution is to use LED stobe/nav lights. It eliminates the power box. Solved my problem plus reduced my empty weight by a few pounds.

 

[CGameProgrammer]

My beacons and strobes are both LEDs.

 

[jakej]

CGP - what type of wire are you using for the led strobes ?
Which brand of strobes did you use ?

 

[CGameProgrammer]

My strobes are these and the beacon is this. The strobe wiring is... I think just regular 18-gauge wire. I can't remember if it's shielded en route to the bus at the front.

 

[Raymo]

Your LED lights must use shielded wires. The MFG typically provides a diagram and wire type requirements.

I suggest reading the Bob Knuckles AeroElectric guide to help mitigate these types of issues ahead of time.

 

[CGameProgrammer]

But it's odd that the noise only comes in when sidetone is on.

 

[mmarien]

I have the AVEO Powerburst lights. The installation manual doesn't indicate that the wiring needs to be shielded. With a max 2A draw you wouldn't think they would give off any interference. Having said that, I used the old wiring which was shielded so I can't say from experience that they don't have interference. The shielding is only in the wing. From VP-X to the connection block under the seats and near the antenna the wiring is NOT shielded.

 

[CGameProgrammer]

By the way I removed both pilot and passenger jacks from the panels, let them hang while ensuring they weren't touching anything, and it had no effect on noise. So they seem to be adequately insulated.

 

[preid]

I built LED wingtip nav lights. The same lights have two different effects and they are based on the Driver to the LED's- 1 is quiet and no issue the other Driver (one supposedly better for noise) causes the noises to the headsets when on.
Same wiring, same lights different Driver. what LED's and Driver are you using?

 

[CGameProgrammer]

I posted links to the strobe and beacon in reply #7. The drivers are built in to them.

 

[preid]

One would think that there would be more than info@aveoengineering.com to contact support to see how they suggest you work around this..
That would be were I would take this troubleshooting, its either a grounding issue (can be tested with using a battery ground instead of the airframe) of a RFI issue from the light (tested by putting a handheld radio tuned to same frequency that is causing issue) this reminds me of a issue I had with HID that at 119.1 near tower (only in the air) I would get radio noise while Light powered on. Never figured it but it wouldnt do at any other frequency or on ground.. hasnt happened since I replaced with LED light. My point is the handheld picked up the noise when i put it near the light power supply (again the driver).

 

[swatson999]

Are you sure it's from the strobes/navs from Aveo? I have Aveo lights (no shielded wires needed) and no noise at all from them.

Have you turned off *everything* but the comm panel or radio, and then one by one turned on each piece of equipment? Sure it isn't something like the transponder replying?

That said, yes...where are you grounding the lights? On the airframe near the wingtip, or are you running a ground wire all the way back to something like a FOT off of the battery?

 

[CGameProgrammer]

The noise is from the lights, yes. They're each on their own circuit breaker and the noise not only occurs only when the light is on, but it exactly corresponds to when the strobes flash or when the beacon turns on (it's an LED blinking non-rotating beacon).

They are not grounded to the frame; they use ground wires that ultimately go to a little bus bar at the front that's connected to the battery. I believe the radio shares that bus, just for ground.

 

[swatson999]

OK...what kind of radio?

 

[CGameProgrammer]

Well it's the Dynon SkyView radio of course. More specifically the 25KHz version, the SV-COM-C25.

 

[mmarien]

They are not grounded to the frame; they use ground wires that ultimately go to a little bus bar at the front that's connected to the battery. I believe the radio shares that bus, just for ground.

Could be a ground loop. I used a different ground bar to ground the avionics. Ultimately they are connected to the same battery but slightly different circuits. Try grounding either the radio or the lights directly to the battery to see if that makes difference.