I have had a couple of setbacks lately.
First, after finishing the intercom, I noticed a bit of crackling noise with the headset noise reduction activated.
I found out that it was coming from the transponder, and that it was a common issue with Bose ANR headsets and ADS-B out transponders.
First I tried temporary installing a different type of transponder antenna, but that didn’t help.
As far as I could tell from various newsgroups, the only solution was to move the antenna further away from the intercom.
So I plugged the original hole and moved the antenna 1 frame further aft.
It didn’t cancel the noise completely, but it is barely noticeable now.
Another issue I came across, was the upper cowl inlet ducts.
I have been postponing them for to long, mostly because I knew the left duct would interfere with the forward prop governor.
The first thing I did was to drill and cleco them to the upper cowl.
Well, it didn’t really take that long to trim it to fit around the governor, but unfortunately I need to trim the forward baffles to fit around the ducts as well.
For now they have been glued to the cowling, then I’ll worry about the baffles next…