MGL Avionics User Forum

I have a V 16 radio when I transmit the side tone has an echo in it. When I receive, it is perfectly clear. I have tried different headsets, cleaned all connections, and this testing has been done with the engine off. Can someone give me some help

This is usually caused by RF feedback - just a little not big enough to start the howling you get in bad cases.
Effectively transmitted signal is getting back into your microphone leads to the radio. Make sure you are using shielded cables and the shields are used in the correct manner (i.e. they are not used to conduct a signal).
A second possibility is a bad antenna match - the reflected energy (the signal not radiated by the antenna) gets back into the radio and causes considerable havoc inside the electronics. Your radio has a SWR meter built in (not hugely accurate but very useful for the purpose). Make sure your SWR number is less than 1.5 at any frequency when you transmit.

The swr is one when transmitting

Can I suggest that you check that your microphone gain is set appropriately. I was surprised by how much attenuation I needed on my V16 to get the audio paths stable. There's a procedure (in the manual I believe) about matching the sidetone volume of your voice to the comms volume. If your own voice when transmitting is noticeably quiter than non-TX general comms volume then your gain is too high. Don't forget, P1 and P2 are set independently.