MGL Avionics User Forum

I have a couple of issues happening to which I have done as much trouble shooting as I know how.
The first issue is that I have noise that seems to be associated with EFIS screens. It is a ticking static noise that changes when I flip through the different EFIS screens. I have Tried several different combinations of grounding between EFIS, V16 and Razer head to no avail. I do have the AUX audio from EFIS hooked up into the V16 for EFIS audio.

The second issue iv had is the tower is always complaining that I sound "scratchy" and they can hardly understand me. I have gone through and followed the recommended set up techniques. Tune to an unused freq. and adjust mic gain until the levels are the same as TX ect. Antenna grounding plane was as per instructions and all coax, antennas ect all were matched up by MGL.

The aircraft is a SPA Panther all metal and yes it is a very loud cockpit. with take off power all bets are off as for hearing anything over the radio. I am using the Bose A20 with a leather mic muff as well.
Any help would be awesome!

Have you disabled the aux audio input from the EFIS to determine whether that's the source of noise? I tried running an MX1 audio into a V16 aux and it was massively noisy.
Re. comm mic quality. What mic gain did you arrive at for A20? I was surprised at the degree of attenuation needed; something like -12dB or more.

How is reception and can you hear other stations clearly? It may be worth testing the antenna coax for connectivity and no shorts between the shield and the core.

Another item to check is all of the audio cables and that the shields are grounded at the radio end only and that the jack plugs for the microphone and headset are electrically isolated from the airframe by the plastic special mounting washers.

Switch your V16 so sidetone from antenna (if it is set to modulator). This effectively switches a receiver directly into the antenna feed and you hear what you are transmitting. ATC will get the same signal. It sounds like you may have some RF leaking into your audio (microphone and leads) when you transmit. That can easily lead to distortion of your signal and in bad cases you will get whistling or howling. In mild cases it may sound like you are talking in a bathroom (somewhat echo-y).

andynoiseboy wrote: ↑Mon Jan 15, 2024 1:57 pm Have you disabled the aux audio input from the EFIS to determine whether that's the source of noise? I tried running an MX1 audio into a V16 aux and it was massively noisy.
Re. comm mic quality. What mic gain did you arrive at for A20? I was surprised at the degree of attenuation needed; something like -12dB or more.

With this disabled it is a lot quieter but noise is still there. Mic gain seems to be in the -3db range to match the transmit audio. Going to experiment with switching off the modulator like he said below and see if that changes anything. Be awhile before I get back to it cause I’m on vacation currently.