Currently just connector friction, not ideal as if you look closely you can see the weight of the power cable swinging the Pi3 to left. I tried a USB cable, but that added a lot of noise, I’ve yet to add the ferrites you suggested. If I don’t add a usb cable, I’ll support the Pi3 in some way, but for now it work, and work well.
edit And make sure you have a good hook… minor damage to my dongle to antenna connector