Hi. I have a Becker AR4201 in my powered aircraft (sorry, I know this group is for glider pilots but I can see that there are some Becker radio experts on here)
When the intercom is switched on there is a 'hiss' in the headphones,engine running or not, but louder with the engine running. I am using Bose anr and Pelltor headsets. When I shield the mic (by putting it in my mouth)the 'hiss' disapears. Is this something to do with the mic setting - SF16 ? Or something else?