GTN 750 and PMA 9000Ex audio panel.
Sidetone seems to vary with selected frequency. With local approach/departure frequency of 120.75 selected, all is normal. When switching to frequency 130.xx and ?up, then there is very loud sidetone. It sounds asif the mic is open and picks up all the cabin noise. It makes for difficult transmitting. No complaints from ATC.
I am puzzled why it changes with frequency. Hope someone can help. No similar issues with the GNC 255 #2 radio.
Is there a way to enter configuration mode (GTN 750) while in flight to play around with side tone and Mic gain settings?
Also, I cannot find any information about these settings (com, sidetone, Mic gain etc) in any GTN750 manual that I can find on line. Anyone knows where I can find this info?
Thanks.
Johan
Sidetone seems to vary with selected frequency. With local approach/departure frequency of 120.75 selected, all is normal. When switching to frequency 130.xx and ?up, then there is very loud sidetone. It sounds asif the mic is open and picks up all the cabin noise. It makes for difficult transmitting. No complaints from ATC.
I am puzzled why it changes with frequency. Hope someone can help. No similar issues with the GNC 255 #2 radio.
Is there a way to enter configuration mode (GTN 750) while in flight to play around with side tone and Mic gain settings?
Also, I cannot find any information about these settings (com, sidetone, Mic gain etc) in any GTN750 manual that I can find on line. Anyone knows where I can find this info?
Thanks.
Johan