[Champ]

I have a D10, D10A, PSE PM1000II intercom, Garmin GNC 300XL gps/comm set up and installed a MakerPlane AMX-2A mini audio panel to get the audio outputs from the D10 & D10A to the intercom (since the 1000II does not have aux inputs). This works well but I am getting noise from the D10A. The D10 is noise free.

I replaced the Dynons audio leads with shielded cables, grounded the shields at the AMX-2A (per MakerPlane instructions) and even pulled these out of the short wire bundle they were in (at Dynon's suggestion) - still no joy.

Still waiting for a response from MakerPlane on the Dynon noise.

Dynon have suggested I send the D10A back for test but I want to see if anyone on VAF has had a similar problem and what they did about it before I do this.

 

[Dynon]

Dennis,
Almost all audio issues are ground issues.

First test is always to verify you have a great ground. Grab a 14 gauge wire, and touch it to a good ground on the D10A (one of the case studs or the shell of the DSUB connector in the back) and then touch it to a great ground on the intercom (often just the case). High chance the noise will go away.

Another option is if your D10A has a battery, is to pull the breaker for the D10A and run off the battery. If that fixes the noise, then again that points to a ground issue.

--Ian
Dynon Avionics

 

[Champ]

Thanks Ian I'll give that a try tomorrow.

 

[Champ]

Success

At Ian's suggestion I pulled the breaker to the D10A and the noise went away with the D10A running on it's internal battery.

Then with the breaker in I disconnected the D10A power ground but it remained on - Hmmm? So I figured it must be getting another ground thru a different source. After checking schematics and my old installation notes I found that someone at Garmin (he shall remain nameless) told me to ground the RS232 shielded altitude run to the GTX327 transponder at both ends. I pulled the shield ground connection at the D10A and the noise went away!