New Radio whine

[yankee-flyer]

I just moved the Dynon readout wires out of the tunnel in an effort to reduce spurious radio noise. I routed them over to the chart box so the computer plug could be stored there. NOW I have an RPM-related whine -- frequency goes up with RPM) that I DIDN'T have before. I'm guessing the cause is a loop of 16-18 inches of coiled wires between the radio and the chart box. Any thoughts? I'm about ready to chop off those rarely use readout wires!..
Thanks
Wayne 120240/143WM

 

[BigJohn]

Hi Wayne,

Why not just shorten the wires so no coil is necessary? Or, keep the whole run to the plug short, within the avionics bay. Check my blog for 10/20/2010 to see how I did it.

John

 

[Mich48041]

Early versions had the PC data going through the Control board to the tunnel. In later versions, the PC serial port is attached to the back of the Dynon D-180 with 6" wires. I assume that your wires are connected to the Control Board. Those wires can be removed from the Control Board and the serial port can be connected directly to the back of the Dynon D-180 EFIS 25-pin D-Sub pins 9, 10, and 22.
9 = white / black (ground)
10 = white / orange
22 = white / yellow
The data wires should be kept away from wires going to the engine.
The serial port can be mounted on the underside of the instrument panel like this:
http://www.vansairforce.com/community/showpost.php?p=478132&postcount=12
or like this:
http://www.vansairforce.com/community/showpost.php?p=533492&postcount=3
Joe Gores

 

[spriteah]

you could try a 2200uf Capacitor near the radio.

Jim