After struggling on placement I finally ground down some 5/8 aluminum nuts and was able to achieve the best fit yet. You can’t see it but there is a ground down nut on the inside and outside of the aft bulkhead which keeps the antenna pointed nearly straight aft. There was *just* enough thread left to get the lock washer and nut on.
The only downside I can see right now it that the additional weight of the required noise filter (seen above as the metal piece on the other side of the bulkhead) and the cable flopping around. I’m going to need to tidy that up.
Antenna cable doesn’t interfere with the elevator pushrod.
Doesn’t interfere with the empennage fairing either.